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Posted to commits@mahout.apache.org by gs...@apache.org on 2009/12/18 00:22:41 UTC

svn commit: r891983 [42/47] - in /lucene/mahout/trunk: ./ core/ core/src/main/java/org/apache/mahout/cf/taste/hadoop/item/ core/src/main/java/org/apache/mahout/clustering/ core/src/main/java/org/apache/mahout/clustering/canopy/ core/src/main/java/org/a...

Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Blas.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Blas.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Blas.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Blas.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,244 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.matrix.DoubleMatrix1D;
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public interface Blas {
+
+  /**
+   * Assigns the result of a function to each cell; <tt>x[row,col] = function(x[row,col])</tt>.
+   *
+   * @param A        the matrix to modify.
+   * @param function a function object taking as argument the current cell's value.
+   * @see org.apache.mahout.math.jet.math.Functions
+   */
+  void assign(DoubleMatrix2D A, org.apache.mahout.math.function.DoubleFunction function);
+
+  /**
+   * Assigns the result of a function to each cell; <tt>x[row,col] = function(x[row,col],y[row,col])</tt>.
+   *
+   * @param x        the matrix to modify.
+   * @param y        the secondary matrix to operate on.
+   * @param function a function object taking as first argument the current cell's value of <tt>this</tt>, and as second
+   *                 argument the current cell's value of <tt>y</tt>,
+   * @return <tt>this</tt> (for convenience only).
+   * @throws IllegalArgumentException if <tt>x.columns() != y.columns() || x.rows() != y.rows()</tt>
+   * @see org.apache.mahout.math.jet.math.Functions
+   */
+  void assign(DoubleMatrix2D x, DoubleMatrix2D y, org.apache.mahout.math.function.DoubleDoubleFunction function);
+
+  /**
+   * Returns the sum of absolute values; <tt>|x[0]| + |x[1]| + ... </tt>. In fact equivalent to
+   * <tt>x.aggregate(Functions.plus, org.apache.mahout.math.jet.math.Functions.abs)</tt>.
+   *
+   * @param x the first vector.
+   */
+  double dasum(DoubleMatrix1D x);
+
+  /**
+   * Combined vector scaling; <tt>y = y + alpha*x</tt>. In fact equivalent to <tt>y.assign(x,org.apache.mahout.math.jet.math.Functions.plusMult(alpha))</tt>.
+   *
+   * @param alpha a scale factor.
+   * @param x     the first source vector.
+   * @param y     the second source vector, this is also the vector where results are stored.
+   * @throws IllegalArgumentException <tt>x.size() != y.size()</tt>..
+   */
+  void daxpy(double alpha, DoubleMatrix1D x, DoubleMatrix1D y);
+
+  /**
+   * Combined matrix scaling; <tt>B = B + alpha*A</tt>. In fact equivalent to <tt>B.assign(A,org.apache.mahout.math.jet.math.Functions.plusMult(alpha))</tt>.
+   *
+   * @param alpha a scale factor.
+   * @param A     the first source matrix.
+   * @param B     the second source matrix, this is also the matrix where results are stored.
+   * @throws IllegalArgumentException if <tt>A.columns() != B.columns() || A.rows() != B.rows()</tt>.
+   */
+  void daxpy(double alpha, DoubleMatrix2D A, DoubleMatrix2D B);
+
+  /**
+   * Vector assignment (copying); <tt>y = x</tt>. In fact equivalent to <tt>y.assign(x)</tt>.
+   *
+   * @param x the source vector.
+   * @param y the destination vector.
+   * @throws IllegalArgumentException <tt>x.size() != y.size()</tt>.
+   */
+  void dcopy(DoubleMatrix1D x, DoubleMatrix1D y);
+
+  /**
+   * Matrix assignment (copying); <tt>B = A</tt>. In fact equivalent to <tt>B.assign(A)</tt>.
+   *
+   * @param A the source matrix.
+   * @param B the destination matrix.
+   * @throws IllegalArgumentException if <tt>A.columns() != B.columns() || A.rows() != B.rows()</tt>.
+   */
+  void dcopy(DoubleMatrix2D A, DoubleMatrix2D B);
+
+  /**
+   * Returns the dot product of two vectors x and y, which is <tt>Sum(x[i]*y[i])</tt>. In fact equivalent to
+   * <tt>x.zDotProduct(y)</tt>.
+   *
+   * @param x the first vector.
+   * @param y the second vector.
+   * @return the sum of products.
+   * @throws IllegalArgumentException if <tt>x.size() != y.size()</tt>.
+   */
+  double ddot(DoubleMatrix1D x, DoubleMatrix1D y);
+
+  /**
+   * Generalized linear algebraic matrix-matrix multiply; <tt>C = alpha*A*B + beta*C</tt>. In fact equivalent to
+   * <tt>A.zMult(B,C,alpha,beta,transposeA,transposeB)</tt>. Note: Matrix shape conformance is checked <i>after</i>
+   * potential transpositions.
+   *
+   * @param transposeA set this flag to indicate that the multiplication shall be performed on A'.
+   * @param transposeB set this flag to indicate that the multiplication shall be performed on B'.
+   * @param alpha      a scale factor.
+   * @param A          the first source matrix.
+   * @param B          the second source matrix.
+   * @param beta       a scale factor.
+   * @param C          the third source matrix, this is also the matrix where results are stored.
+   * @throws IllegalArgumentException if <tt>B.rows() != A.columns()</tt>.
+   * @throws IllegalArgumentException if <tt>C.rows() != A.rows() || C.columns() != B.columns()</tt>.
+   * @throws IllegalArgumentException if <tt>A == C || B == C</tt>.
+   */
+  void dgemm(boolean transposeA, boolean transposeB, double alpha, DoubleMatrix2D A, DoubleMatrix2D B, double beta,
+             DoubleMatrix2D C);
+
+  /**
+   * Generalized linear algebraic matrix-vector multiply; <tt>y = alpha*A*x + beta*y</tt>. In fact equivalent to
+   * <tt>A.zMult(x,y,alpha,beta,transposeA)</tt>. Note: Matrix shape conformance is checked <i>after</i> potential
+   * transpositions.
+   *
+   * @param transposeA set this flag to indicate that the multiplication shall be performed on A'.
+   * @param alpha      a scale factor.
+   * @param A          the source matrix.
+   * @param x          the first source vector.
+   * @param beta       a scale factor.
+   * @param y          the second source vector, this is also the vector where results are stored.
+   * @throws IllegalArgumentException <tt>A.columns() != x.size() || A.rows() != y.size())</tt>..
+   */
+  void dgemv(boolean transposeA, double alpha, DoubleMatrix2D A, DoubleMatrix1D x, double beta, DoubleMatrix1D y);
+
+  /**
+   * Performs a rank 1 update; <tt>A = A + alpha*x*y'</tt>. Example:
+   * <pre>
+   * A = { {6,5}, {7,6} }, x = {1,2}, y = {3,4}, alpha = 1 -->
+   * A = { {9,9}, {13,14} }
+   * </pre>
+   *
+   * @param alpha a scalar.
+   * @param x     an m element vector.
+   * @param y     an n element vector.
+   * @param A     an m by n matrix.
+   */
+  void dger(double alpha, DoubleMatrix1D x, DoubleMatrix1D y, DoubleMatrix2D A);
+
+  /**
+   * Return the 2-norm; <tt>sqrt(x[0]^2 + x[1]^2 + ...)</tt>. In fact equivalent to
+   * <tt>Math.sqrt(Algebra.DEFAULT.norm2(x))</tt>.
+   *
+   * @param x the vector.
+   */
+  double dnrm2(DoubleMatrix1D x);
+
+  /**
+   * Applies a givens plane rotation to (x,y); <tt>x = c*x + s*y; y = c*y - s*x</tt>.
+   *
+   * @param x the first vector.
+   * @param y the second vector.
+   * @param c the cosine of the angle of rotation.
+   * @param s the sine of the angle of rotation.
+   */
+  void drot(DoubleMatrix1D x, DoubleMatrix1D y, double c, double s);
+
+  /**
+   * Constructs a Givens plane rotation for <tt>(a,b)</tt>. Taken from the LINPACK translation from FORTRAN to Java,
+   * interface slightly modified. In the LINPACK listing DROTG is attributed to Jack Dongarra
+   *
+   * @param a      rotational elimination parameter a.
+   * @param b      rotational elimination parameter b.
+   * @param rotvec Must be at least of length 4. On output contains the values <tt>{a,b,c,s}</tt>.
+   */
+  void drotg(double a, double b, double[] rotvec);
+
+  /**
+   * Vector scaling; <tt>x = alpha*x</tt>. In fact equivalent to <tt>x.assign(Functions.mult(alpha))</tt>.
+   *
+   * @param alpha a scale factor.
+   * @param x     the first vector.
+   */
+  void dscal(double alpha, DoubleMatrix1D x);
+
+  /**
+   * Matrix scaling; <tt>A = alpha*A</tt>. In fact equivalent to <tt>A.assign(Functions.mult(alpha))</tt>.
+   *
+   * @param alpha a scale factor.
+   * @param A     the matrix.
+   */
+  void dscal(double alpha, DoubleMatrix2D A);
+
+  /**
+   * Swaps the elements of two vectors; <tt>y <==> x</tt>. In fact equivalent to <tt>y.swap(x)</tt>.
+   *
+   * @param x the first vector.
+   * @param y the second vector.
+   * @throws IllegalArgumentException <tt>x.size() != y.size()</tt>.
+   */
+  void dswap(DoubleMatrix1D x, DoubleMatrix1D y);
+
+  /**
+   * Swaps the elements of two matrices; <tt>B <==> A</tt>.
+   *
+   * @param x the first matrix.
+   * @param y the second matrix.
+   * @throws IllegalArgumentException if <tt>A.columns() != B.columns() || A.rows() != B.rows()</tt>.
+   */
+  void dswap(DoubleMatrix2D x, DoubleMatrix2D y);
+
+  /**
+   * Symmetric matrix-vector multiplication; <tt>y = alpha*A*x + beta*y</tt>. Where alpha and beta are scalars, x and y
+   * are n element vectors and A is an n by n symmetric matrix. A can be in upper or lower triangular format.
+   *
+   * @param isUpperTriangular is A upper triangular or lower triangular part to be used?
+   * @param alpha             scaling factor.
+   * @param A                 the source matrix.
+   * @param x                 the first source vector.
+   * @param beta              scaling factor.
+   * @param y                 the second vector holding source and destination.
+   */
+  void dsymv(boolean isUpperTriangular, double alpha, DoubleMatrix2D A, DoubleMatrix1D x, double beta,
+             DoubleMatrix1D y);
+
+  /**
+   * Triangular matrix-vector multiplication; <tt>x = A*x</tt> or <tt>x = A'*x</tt>. Where x is an n element vector and
+   * A is an n by n unit, or non-unit, upper or lower triangular matrix.
+   *
+   * @param isUpperTriangular is A upper triangular or lower triangular?
+   * @param transposeA        set this flag to indicate that the multiplication shall be performed on A'.
+   * @param isUnitTriangular  true --> A is assumed to be unit triangular; false --> A is not assumed to be unit
+   *                          triangular
+   * @param A                 the source matrix.
+   * @param x                 the vector holding source and destination.
+   */
+  void dtrmv(boolean isUpperTriangular, boolean transposeA, boolean isUnitTriangular, DoubleMatrix2D A,
+             DoubleMatrix1D x);
+
+  /**
+   * Returns the index of largest absolute value; <tt>i such that |x[i]| == max(|x[0]|,|x[1]|,...).</tt>.
+   *
+   * @param x the vector to search through.
+   * @return the index of largest absolute value (-1 if x is empty).
+   */
+  int idamax(DoubleMatrix1D x);
+
+
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Blas.java
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Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/CholeskyDecomposition.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/CholeskyDecomposition.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/CholeskyDecomposition.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/CholeskyDecomposition.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,228 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.jet.math.Functions;
+import org.apache.mahout.math.matrix.DoubleFactory2D;
+import org.apache.mahout.math.matrix.DoubleMatrix1D;
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public class CholeskyDecomposition implements java.io.Serializable {
+
+  /** Array for internal storage of decomposition. */
+  //private double[][] L;
+  private final DoubleMatrix2D L;
+
+  /** Row and column dimension (square matrix). */
+  private final int n;
+
+  /** Symmetric and positive definite flag. */
+  private boolean isSymmetricPositiveDefinite;
+
+  /**
+   * Constructs and returns a new Cholesky decomposition object for a symmetric and positive definite matrix; The
+   * decomposed matrices can be retrieved via instance methods of the returned decomposition object.
+   *
+   * @param A Square, symmetric matrix.
+   * @return Structure to access <tt>L</tt> and <tt>isSymmetricPositiveDefinite</tt> flag.
+   * @throws IllegalArgumentException if <tt>A</tt> is not square.
+   */
+  public CholeskyDecomposition(DoubleMatrix2D A) {
+    Property.DEFAULT.checkSquare(A);
+    // Initialize.
+    //double[][] A = Arg.getArray();
+
+    n = A.rows();
+    //L = new double[n][n];
+    L = A.like(n, n);
+    isSymmetricPositiveDefinite = (A.columns() == n);
+
+    //precompute and cache some views to avoid regenerating them time and again
+    DoubleMatrix1D[] Lrows = new DoubleMatrix1D[n];
+    for (int j = 0; j < n; j++) {
+      Lrows[j] = L.viewRow(j);
+    }
+
+    // Main loop.
+    for (int j = 0; j < n; j++) {
+      //double[] Lrowj = L[j];
+      //DoubleMatrix1D Lrowj = L.viewRow(j);
+      double d = 0.0;
+      for (int k = 0; k < j; k++) {
+        //double[] Lrowk = L[k];
+        double s = Lrows[k].zDotProduct(Lrows[j], 0, k);
+        /*
+        DoubleMatrix1D Lrowk = L.viewRow(k);
+        double s = 0.0;
+        for (int i = 0; i < k; i++) {
+           s += Lrowk.getQuick(i)*Lrowj.getQuick(i);
+        }
+        */
+        s = (A.getQuick(j, k) - s) / L.getQuick(k, k);
+        Lrows[j].setQuick(k, s);
+        d += s * s;
+        isSymmetricPositiveDefinite = isSymmetricPositiveDefinite && (A.getQuick(k, j) == A.getQuick(j, k));
+      }
+      d = A.getQuick(j, j) - d;
+      isSymmetricPositiveDefinite = isSymmetricPositiveDefinite && (d > 0.0);
+      L.setQuick(j, j, Math.sqrt(Math.max(d, 0.0)));
+
+      for (int k = j + 1; k < n; k++) {
+        L.setQuick(j, k, 0.0);
+      }
+    }
+  }
+
+  /**
+   * Returns the triangular factor, <tt>L</tt>.
+   *
+   * @return <tt>L</tt>
+   */
+  public DoubleMatrix2D getL() {
+    return L;
+  }
+
+  /**
+   * Returns whether the matrix <tt>A</tt> is symmetric and positive definite.
+   *
+   * @return true if <tt>A</tt> is symmetric and positive definite; false otherwise
+   */
+  public boolean isSymmetricPositiveDefinite() {
+    return isSymmetricPositiveDefinite;
+  }
+
+  /**
+   * Solves <tt>A*X = B</tt>; returns <tt>X</tt>.
+   *
+   * @param B A Matrix with as many rows as <tt>A</tt> and any number of columns.
+   * @return <tt>X</tt> so that <tt>L*L'*X = B</tt>.
+   * @throws IllegalArgumentException if <tt>B.rows() != A.rows()</tt>.
+   * @throws IllegalArgumentException if <tt>!isSymmetricPositiveDefinite()</tt>.
+   */
+  public DoubleMatrix2D solve(DoubleMatrix2D B) {
+    // Copy right hand side.
+    DoubleMatrix2D X = B.copy();
+    int nx = B.columns();
+
+    // fix by MG Ferreira <mg...@webmail.co.za>
+    // old code is in method xxxSolveBuggy()
+    for (int c = 0; c < nx; c++) {
+      // Solve L*Y = B;
+      for (int i = 0; i < n; i++) {
+        double sum = B.getQuick(i, c);
+        for (int k = i - 1; k >= 0; k--) {
+          sum -= L.getQuick(i, k) * X.getQuick(k, c);
+        }
+        X.setQuick(i, c, sum / L.getQuick(i, i));
+      }
+
+      // Solve L'*X = Y;
+      for (int i = n - 1; i >= 0; i--) {
+        double sum = X.getQuick(i, c);
+        for (int k = i + 1; k < n; k++) {
+          sum -= L.getQuick(k, i) * X.getQuick(k, c);
+        }
+        X.setQuick(i, c, sum / L.getQuick(i, i));
+      }
+    }
+
+    return X;
+  }
+
+  /**
+   * Solves <tt>A*X = B</tt>; returns <tt>X</tt>.
+   *
+   * @param B A Matrix with as many rows as <tt>A</tt> and any number of columns.
+   * @return <tt>X</tt> so that <tt>L*L'*X = B</tt>.
+   * @throws IllegalArgumentException if <tt>B.rows() != A.rows()</tt>.
+   * @throws IllegalArgumentException if <tt>!isSymmetricPositiveDefinite()</tt>.
+   */
+  private DoubleMatrix2D XXXsolveBuggy(DoubleMatrix2D B) {
+    if (B.rows() != n) {
+      throw new IllegalArgumentException("Matrix row dimensions must agree.");
+    }
+    if (!isSymmetricPositiveDefinite) {
+      throw new IllegalArgumentException("Matrix is not symmetric positive definite.");
+    }
+
+    // Copy right hand side.
+    DoubleMatrix2D X = B.copy();
+    //int nx = B.columns();
+
+    // precompute and cache some views to avoid regenerating them time and again
+    DoubleMatrix1D[] Xrows = new DoubleMatrix1D[n];
+    for (int k = 0; k < n; k++) {
+      Xrows[k] = X.viewRow(k);
+    }
+
+    // Solve L*Y = B;
+    for (int k = 0; k < n; k++) {
+      for (int i = k + 1; i < n; i++) {
+        // X[i,j] -= X[k,j]*L[i,k]
+        Xrows[i].assign(Xrows[k], Functions.minusMult(L.getQuick(i, k)));
+      }
+      Xrows[k].assign(Functions.div(L.getQuick(k, k)));
+    }
+
+    // Solve L'*X = Y;
+    for (int k = n - 1; k >= 0; k--) {
+      Xrows[k].assign(Functions.div(L.getQuick(k, k)));
+      for (int i = 0; i < k; i++) {
+        // X[i,j] -= X[k,j]*L[k,i]
+        Xrows[i].assign(Xrows[k], Functions.minusMult(L.getQuick(k, i)));
+      }
+    }
+    return X;
+  }
+
+  /**
+   * Returns a String with (propertyName, propertyValue) pairs. Useful for debugging or to quickly get the rough
+   * picture. For example,
+   * <pre>
+   * rank          : 3
+   * trace         : 0
+   * </pre>
+   */
+  public String toString() {
+    StringBuilder buf = new StringBuilder();
+
+    buf.append("--------------------------------------------------------------------------\n");
+    buf.append("CholeskyDecomposition(A) --> isSymmetricPositiveDefinite(A), L, inverse(A)\n");
+    buf.append("--------------------------------------------------------------------------\n");
+
+    buf.append("isSymmetricPositiveDefinite = ");
+    String unknown = "Illegal operation or error: ";
+    try {
+      buf.append(String.valueOf(this.isSymmetricPositiveDefinite()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\nL = ");
+    try {
+      buf.append(String.valueOf(this.getL()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\ninverse(A) = ");
+    try {
+      buf.append(String.valueOf(this.solve(DoubleFactory2D.dense.identity(L.rows()))));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    return buf.toString();
+  }
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/CholeskyDecomposition.java
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Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Diagonal.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Diagonal.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Diagonal.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Diagonal.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,35 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** For diagonal matrices we can often do better. */
+class Diagonal {
+
+  private Diagonal() {
+  }
+
+  /**
+   * Modifies A to hold its inverse.
+   *
+   * @return isNonSingular.
+   * @throws IllegalArgumentException if <tt>x.size() != y.size()</tt>.
+   */
+  public static boolean inverse(DoubleMatrix2D A) {
+    Property.DEFAULT.checkSquare(A);
+    boolean isNonSingular = true;
+    for (int i = A.rows(); --i >= 0;) {
+      double v = A.getQuick(i, i);
+      isNonSingular &= (v != 0);
+      A.setQuick(i, i, 1 / v);
+    }
+    return isNonSingular;
+  }
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Diagonal.java
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Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/EigenvalueDecomposition.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/EigenvalueDecomposition.java?rev=891983&view=auto
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--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/EigenvalueDecomposition.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/EigenvalueDecomposition.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,969 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.matrix.DoubleFactory1D;
+import org.apache.mahout.math.matrix.DoubleFactory2D;
+import org.apache.mahout.math.matrix.DoubleMatrix1D;
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public class EigenvalueDecomposition implements java.io.Serializable {
+
+  /** Row and column dimension (square matrix). */
+  private final int n;
+
+  /** Arrays for internal storage of eigenvalues. */
+  private final double[] d, e;
+
+  /** Array for internal storage of eigenvectors. */
+  private final double[][] V;
+
+  /** Array for internal storage of nonsymmetric Hessenberg form. */
+  private double[][] H;
+
+  /** Working storage for nonsymmetric algorithm. */
+  private double[] ort;
+
+  // Complex scalar division.
+
+  private transient double cdivr, cdivi;
+
+  /**
+   * Constructs and returns a new eigenvalue decomposition object; The decomposed matrices can be retrieved via instance
+   * methods of the returned decomposition object. Checks for symmetry, then constructs the eigenvalue decomposition.
+   *
+   * @param A A square matrix.
+   * @return A decomposition object to access <tt>D</tt> and <tt>V</tt>.
+   * @throws IllegalArgumentException if <tt>A</tt> is not square.
+   */
+  public EigenvalueDecomposition(DoubleMatrix2D A) {
+    Property.DEFAULT.checkSquare(A);
+
+    n = A.columns();
+    V = new double[n][n];
+    d = new double[n];
+    e = new double[n];
+
+    boolean issymmetric = Property.DEFAULT.isSymmetric(A);
+
+    if (issymmetric) {
+      for (int i = 0; i < n; i++) {
+        for (int j = 0; j < n; j++) {
+          V[i][j] = A.getQuick(i, j);
+        }
+      }
+
+      // Tridiagonalize.
+      tred2();
+
+      // Diagonalize.
+      tql2();
+
+    } else {
+      H = new double[n][n];
+      ort = new double[n];
+
+      for (int j = 0; j < n; j++) {
+        for (int i = 0; i < n; i++) {
+          H[i][j] = A.getQuick(i, j);
+        }
+      }
+
+      // Reduce to Hessenberg form.
+      orthes();
+
+      // Reduce Hessenberg to real Schur form.
+      hqr2();
+    }
+  }
+
+  private void cdiv(double xr, double xi, double yr, double yi) {
+    double r, d;
+    if (Math.abs(yr) > Math.abs(yi)) {
+      r = yi / yr;
+      d = yr + r * yi;
+      cdivr = (xr + r * xi) / d;
+      cdivi = (xi - r * xr) / d;
+    } else {
+      r = yr / yi;
+      d = yi + r * yr;
+      cdivr = (r * xr + xi) / d;
+      cdivi = (r * xi - xr) / d;
+    }
+  }
+
+  /**
+   * Returns the block diagonal eigenvalue matrix, <tt>D</tt>.
+   *
+   * @return <tt>D</tt>
+   */
+  public DoubleMatrix2D getD() {
+    double[][] D = new double[n][n];
+    for (int i = 0; i < n; i++) {
+      for (int j = 0; j < n; j++) {
+        D[i][j] = 0.0;
+      }
+      D[i][i] = d[i];
+      if (e[i] > 0) {
+        D[i][i + 1] = e[i];
+      } else if (e[i] < 0) {
+        D[i][i - 1] = e[i];
+      }
+    }
+    return DoubleFactory2D.dense.make(D);
+  }
+
+  /**
+   * Returns the imaginary parts of the eigenvalues.
+   *
+   * @return imag(diag(D))
+   */
+  public DoubleMatrix1D getImagEigenvalues() {
+    return DoubleFactory1D.dense.make(e);
+  }
+
+  /**
+   * Returns the real parts of the eigenvalues.
+   *
+   * @return real(diag(D))
+   */
+  public DoubleMatrix1D getRealEigenvalues() {
+    return DoubleFactory1D.dense.make(d);
+  }
+
+  /**
+   * Returns the eigenvector matrix, <tt>V</tt>
+   *
+   * @return <tt>V</tt>
+   */
+  public DoubleMatrix2D getV() {
+    return DoubleFactory2D.dense.make(V);
+  }
+
+  /** Nonsymmetric reduction from Hessenberg to real Schur form. */
+  private void hqr2() {
+    //  This is derived from the Algol procedure hqr2,
+    //  by Martin and Wilkinson, Handbook for Auto. Comp.,
+    //  Vol.ii-Linear Algebra, and the corresponding
+    //  Fortran subroutine in EISPACK.
+
+    // Initialize
+
+    int nn = this.n;
+    int n = nn - 1;
+    int low = 0;
+    int high = nn - 1;
+    double eps = Math.pow(2.0, -52.0);
+
+    // Store roots isolated by balanc and compute matrix norm
+
+    double norm = 0.0;
+    for (int i = 0; i < nn; i++) {
+      if (i < low || i > high) {
+        d[i] = H[i][i];
+        e[i] = 0.0;
+      }
+      for (int j = Math.max(i - 1, 0); j < nn; j++) {
+        norm += Math.abs(H[i][j]);
+      }
+    }
+
+    // Outer loop over eigenvalue index
+
+    int iter = 0;
+    double y;
+    double x;
+    double w;
+    double z = 0;
+    double s = 0;
+    double r = 0;
+    double q = 0;
+    double p = 0;
+    double exshift = 0.0;
+    while (n >= low) {
+
+      // Look for single small sub-diagonal element
+
+      int l = n;
+      while (l > low) {
+        s = Math.abs(H[l - 1][l - 1]) + Math.abs(H[l][l]);
+        if (s == 0.0) {
+          s = norm;
+        }
+        if (Math.abs(H[l][l - 1]) < eps * s) {
+          break;
+        }
+        l--;
+      }
+
+      // Check for convergence
+      // One root found
+
+      if (l == n) {
+        H[n][n] += exshift;
+        d[n] = H[n][n];
+        e[n] = 0.0;
+        n--;
+        iter = 0;
+
+        // Two roots found
+
+      } else if (l == n - 1) {
+        w = H[n][n - 1] * H[n - 1][n];
+        p = (H[n - 1][n - 1] - H[n][n]) / 2.0;
+        q = p * p + w;
+        z = Math.sqrt(Math.abs(q));
+        H[n][n] += exshift;
+        H[n - 1][n - 1] += exshift;
+        x = H[n][n];
+
+        // Real pair
+
+        if (q >= 0) {
+          if (p >= 0) {
+            z = p + z;
+          } else {
+            z = p - z;
+          }
+          d[n - 1] = x + z;
+          d[n] = d[n - 1];
+          if (z != 0.0) {
+            d[n] = x - w / z;
+          }
+          e[n - 1] = 0.0;
+          e[n] = 0.0;
+          x = H[n][n - 1];
+          s = Math.abs(x) + Math.abs(z);
+          p = x / s;
+          q = z / s;
+          r = Math.sqrt(p * p + q * q);
+          p /= r;
+          q /= r;
+
+          // Row modification
+
+          for (int j = n - 1; j < nn; j++) {
+            z = H[n - 1][j];
+            H[n - 1][j] = q * z + p * H[n][j];
+            H[n][j] = q * H[n][j] - p * z;
+          }
+
+          // Column modification
+
+          for (int i = 0; i <= n; i++) {
+            z = H[i][n - 1];
+            H[i][n - 1] = q * z + p * H[i][n];
+            H[i][n] = q * H[i][n] - p * z;
+          }
+
+          // Accumulate transformations
+
+          for (int i = low; i <= high; i++) {
+            z = V[i][n - 1];
+            V[i][n - 1] = q * z + p * V[i][n];
+            V[i][n] = q * V[i][n] - p * z;
+          }
+
+          // Complex pair
+
+        } else {
+          d[n - 1] = x + p;
+          d[n] = x + p;
+          e[n - 1] = z;
+          e[n] = -z;
+        }
+        n -= 2;
+        iter = 0;
+
+        // No convergence yet
+
+      } else {
+
+        // Form shift
+
+        x = H[n][n];
+        y = 0.0;
+        w = 0.0;
+        if (l < n) {
+          y = H[n - 1][n - 1];
+          w = H[n][n - 1] * H[n - 1][n];
+        }
+
+        // Wilkinson's original ad hoc shift
+
+        if (iter == 10) {
+          exshift += x;
+          for (int i = low; i <= n; i++) {
+            H[i][i] -= x;
+          }
+          s = Math.abs(H[n][n - 1]) + Math.abs(H[n - 1][n - 2]);
+          x = y = 0.75 * s;
+          w = -0.4375 * s * s;
+        }
+
+        // MATLAB's new ad hoc shift
+
+        if (iter == 30) {
+          s = (y - x) / 2.0;
+          s = s * s + w;
+          if (s > 0) {
+            s = Math.sqrt(s);
+            if (y < x) {
+              s = -s;
+            }
+            s = x - w / ((y - x) / 2.0 + s);
+            for (int i = low; i <= n; i++) {
+              H[i][i] -= s;
+            }
+            exshift += s;
+            x = y = w = 0.964;
+          }
+        }
+
+        iter += 1;   // (Could check iteration count here.)
+
+        // Look for two consecutive small sub-diagonal elements
+
+        int m = n - 2;
+        while (m >= l) {
+          z = H[m][m];
+          r = x - z;
+          s = y - z;
+          p = (r * s - w) / H[m + 1][m] + H[m][m + 1];
+          q = H[m + 1][m + 1] - z - r - s;
+          r = H[m + 2][m + 1];
+          s = Math.abs(p) + Math.abs(q) + Math.abs(r);
+          p /= s;
+          q /= s;
+          r /= s;
+          if (m == l) {
+            break;
+          }
+          if (Math.abs(H[m][m - 1]) * (Math.abs(q) + Math.abs(r)) <
+              eps * (Math.abs(p) * (Math.abs(H[m - 1][m - 1]) + Math.abs(z) +
+                  Math.abs(H[m + 1][m + 1])))) {
+            break;
+          }
+          m--;
+        }
+
+        for (int i = m + 2; i <= n; i++) {
+          H[i][i - 2] = 0.0;
+          if (i > m + 2) {
+            H[i][i - 3] = 0.0;
+          }
+        }
+
+        // Double QR step involving rows l:n and columns m:n
+
+        for (int k = m; k <= n - 1; k++) {
+          boolean notlast = (k != n - 1);
+          if (k != m) {
+            p = H[k][k - 1];
+            q = H[k + 1][k - 1];
+            r = (notlast ? H[k + 2][k - 1] : 0.0);
+            x = Math.abs(p) + Math.abs(q) + Math.abs(r);
+            if (x != 0.0) {
+              p /= x;
+              q /= x;
+              r /= x;
+            }
+          }
+          if (x == 0.0) {
+            break;
+          }
+          s = Math.sqrt(p * p + q * q + r * r);
+          if (p < 0) {
+            s = -s;
+          }
+          if (s != 0) {
+            if (k != m) {
+              H[k][k - 1] = -s * x;
+            } else if (l != m) {
+              H[k][k - 1] = -H[k][k - 1];
+            }
+            p += s;
+            x = p / s;
+            y = q / s;
+            z = r / s;
+            q /= p;
+            r /= p;
+
+            // Row modification
+
+            for (int j = k; j < nn; j++) {
+              p = H[k][j] + q * H[k + 1][j];
+              if (notlast) {
+                p += r * H[k + 2][j];
+                H[k + 2][j] -= p * z;
+              }
+              H[k][j] -= p * x;
+              H[k + 1][j] -= p * y;
+            }
+
+            // Column modification
+
+            for (int i = 0; i <= Math.min(n, k + 3); i++) {
+              p = x * H[i][k] + y * H[i][k + 1];
+              if (notlast) {
+                p += z * H[i][k + 2];
+                H[i][k + 2] -= p * r;
+              }
+              H[i][k] -= p;
+              H[i][k + 1] -= p * q;
+            }
+
+            // Accumulate transformations
+
+            for (int i = low; i <= high; i++) {
+              p = x * V[i][k] + y * V[i][k + 1];
+              if (notlast) {
+                p += z * V[i][k + 2];
+                V[i][k + 2] -= p * r;
+              }
+              V[i][k] -= p;
+              V[i][k + 1] -= p * q;
+            }
+          }  // (s != 0)
+        }  // k loop
+      }  // check convergence
+    }  // while (n >= low)
+
+    // Backsubstitute to find vectors of upper triangular form
+
+    if (norm == 0.0) {
+      return;
+    }
+
+    for (n = nn - 1; n >= 0; n--) {
+      p = d[n];
+      q = e[n];
+
+      // Real vector
+
+      double t;
+      if (q == 0) {
+        int l = n;
+        H[n][n] = 1.0;
+        for (int i = n - 1; i >= 0; i--) {
+          w = H[i][i] - p;
+          r = 0.0;
+          for (int j = l; j <= n; j++) {
+            r += H[i][j] * H[j][n];
+          }
+          if (e[i] < 0.0) {
+            z = w;
+            s = r;
+          } else {
+            l = i;
+            if (e[i] == 0.0) {
+              if (w != 0.0) {
+                H[i][n] = -r / w;
+              } else {
+                H[i][n] = -r / (eps * norm);
+              }
+
+              // Solve real equations
+
+            } else {
+              x = H[i][i + 1];
+              y = H[i + 1][i];
+              q = (d[i] - p) * (d[i] - p) + e[i] * e[i];
+              t = (x * s - z * r) / q;
+              H[i][n] = t;
+              if (Math.abs(x) > Math.abs(z)) {
+                H[i + 1][n] = (-r - w * t) / x;
+              } else {
+                H[i + 1][n] = (-s - y * t) / z;
+              }
+            }
+
+            // Overflow control
+
+            t = Math.abs(H[i][n]);
+            if ((eps * t) * t > 1) {
+              for (int j = i; j <= n; j++) {
+                H[j][n] /= t;
+              }
+            }
+          }
+        }
+
+        // Complex vector
+
+      } else if (q < 0) {
+        int l = n - 1;
+
+        // Last vector component imaginary so matrix is triangular
+
+        if (Math.abs(H[n][n - 1]) > Math.abs(H[n - 1][n])) {
+          H[n - 1][n - 1] = q / H[n][n - 1];
+          H[n - 1][n] = -(H[n][n] - p) / H[n][n - 1];
+        } else {
+          cdiv(0.0, -H[n - 1][n], H[n - 1][n - 1] - p, q);
+          H[n - 1][n - 1] = cdivr;
+          H[n - 1][n] = cdivi;
+        }
+        H[n][n - 1] = 0.0;
+        H[n][n] = 1.0;
+        for (int i = n - 2; i >= 0; i--) {
+          double ra = 0.0;
+          double sa = 0.0;
+          for (int j = l; j <= n; j++) {
+            ra += H[i][j] * H[j][n - 1];
+            sa += H[i][j] * H[j][n];
+          }
+          w = H[i][i] - p;
+
+          if (e[i] < 0.0) {
+            z = w;
+            r = ra;
+            s = sa;
+          } else {
+            l = i;
+            if (e[i] == 0) {
+              cdiv(-ra, -sa, w, q);
+              H[i][n - 1] = cdivr;
+              H[i][n] = cdivi;
+            } else {
+
+              // Solve complex equations
+
+              x = H[i][i + 1];
+              y = H[i + 1][i];
+              double vr = (d[i] - p) * (d[i] - p) + e[i] * e[i] - q * q;
+              double vi = (d[i] - p) * 2.0 * q;
+              if (vr == 0.0 && vi == 0.0) {
+                vr = eps * norm * (Math.abs(w) + Math.abs(q) +
+                    Math.abs(x) + Math.abs(y) + Math.abs(z));
+              }
+              cdiv(x * r - z * ra + q * sa, x * s - z * sa - q * ra, vr, vi);
+              H[i][n - 1] = cdivr;
+              H[i][n] = cdivi;
+              if (Math.abs(x) > (Math.abs(z) + Math.abs(q))) {
+                H[i + 1][n - 1] = (-ra - w * H[i][n - 1] + q * H[i][n]) / x;
+                H[i + 1][n] = (-sa - w * H[i][n] - q * H[i][n - 1]) / x;
+              } else {
+                cdiv(-r - y * H[i][n - 1], -s - y * H[i][n], z, q);
+                H[i + 1][n - 1] = cdivr;
+                H[i + 1][n] = cdivi;
+              }
+            }
+
+            // Overflow control
+
+            t = Math.max(Math.abs(H[i][n - 1]), Math.abs(H[i][n]));
+            if ((eps * t) * t > 1) {
+              for (int j = i; j <= n; j++) {
+                H[j][n - 1] /= t;
+                H[j][n] /= t;
+              }
+            }
+          }
+        }
+      }
+    }
+
+    // Vectors of isolated roots
+
+    for (int i = 0; i < nn; i++) {
+      if (i < low || i > high) {
+        System.arraycopy(H[i], i, V[i], i, nn - i);
+      }
+    }
+
+    // Back transformation to get eigenvectors of original matrix
+
+    for (int j = nn - 1; j >= low; j--) {
+      for (int i = low; i <= high; i++) {
+        z = 0.0;
+        for (int k = low; k <= Math.min(j, high); k++) {
+          z += V[i][k] * H[k][j];
+        }
+        V[i][j] = z;
+      }
+    }
+  }
+
+  /** Nonsymmetric reduction to Hessenberg form. */
+  private void orthes() {
+    //  This is derived from the Algol procedures orthes and ortran,
+    //  by Martin and Wilkinson, Handbook for Auto. Comp.,
+    //  Vol.ii-Linear Algebra, and the corresponding
+    //  Fortran subroutines in EISPACK.
+
+    int low = 0;
+    int high = n - 1;
+
+    for (int m = low + 1; m <= high - 1; m++) {
+
+      // Scale column.
+
+      double scale = 0.0;
+      for (int i = m; i <= high; i++) {
+        scale += Math.abs(H[i][m - 1]);
+      }
+      if (scale != 0.0) {
+
+        // Compute Householder transformation.
+
+        double h = 0.0;
+        for (int i = high; i >= m; i--) {
+          ort[i] = H[i][m - 1] / scale;
+          h += ort[i] * ort[i];
+        }
+        double g = Math.sqrt(h);
+        if (ort[m] > 0) {
+          g = -g;
+        }
+        h -= ort[m] * g;
+        ort[m] -= g;
+
+        // Apply Householder similarity transformation
+        // H = (I-u*u'/h)*H*(I-u*u')/h)
+
+        for (int j = m; j < n; j++) {
+          double f = 0.0;
+          for (int i = high; i >= m; i--) {
+            f += ort[i] * H[i][j];
+          }
+          f /= h;
+          for (int i = m; i <= high; i++) {
+            H[i][j] -= f * ort[i];
+          }
+        }
+
+        for (int i = 0; i <= high; i++) {
+          double f = 0.0;
+          for (int j = high; j >= m; j--) {
+            f += ort[j] * H[i][j];
+          }
+          f /= h;
+          for (int j = m; j <= high; j++) {
+            H[i][j] -= f * ort[j];
+          }
+        }
+        ort[m] = scale * ort[m];
+        H[m][m - 1] = scale * g;
+      }
+    }
+
+    // Accumulate transformations (Algol's ortran).
+
+    for (int i = 0; i < n; i++) {
+      for (int j = 0; j < n; j++) {
+        V[i][j] = (i == j ? 1.0 : 0.0);
+      }
+    }
+
+    for (int m = high - 1; m >= low + 1; m--) {
+      if (H[m][m - 1] != 0.0) {
+        for (int i = m + 1; i <= high; i++) {
+          ort[i] = H[i][m - 1];
+        }
+        for (int j = m; j <= high; j++) {
+          double g = 0.0;
+          for (int i = m; i <= high; i++) {
+            g += ort[i] * V[i][j];
+          }
+          // Double division avoids possible underflow
+          g = (g / ort[m]) / H[m][m - 1];
+          for (int i = m; i <= high; i++) {
+            V[i][j] += g * ort[i];
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Returns a String with (propertyName, propertyValue) pairs. Useful for debugging or to quickly get the rough
+   * picture. For example,
+   * <pre>
+   * rank          : 3
+   * trace         : 0
+   * </pre>
+   */
+  public String toString() {
+    StringBuilder buf = new StringBuilder();
+
+    buf.append("---------------------------------------------------------------------\n");
+    buf.append("EigenvalueDecomposition(A) --> D, V, realEigenvalues, imagEigenvalues\n");
+    buf.append("---------------------------------------------------------------------\n");
+
+    buf.append("realEigenvalues = ");
+    String unknown = "Illegal operation or error: ";
+    try {
+      buf.append(String.valueOf(this.getRealEigenvalues()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\nimagEigenvalues = ");
+    try {
+      buf.append(String.valueOf(this.getImagEigenvalues()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\nD = ");
+    try {
+      buf.append(String.valueOf(this.getD()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\nV = ");
+    try {
+      buf.append(String.valueOf(this.getV()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    return buf.toString();
+  }
+
+  /** Symmetric tridiagonal QL algorithm. */
+  private void tql2() {
+
+    //  This is derived from the Algol procedures tql2, by
+    //  Bowdler, Martin, Reinsch, and Wilkinson, Handbook for
+    //  Auto. Comp., Vol.ii-Linear Algebra, and the corresponding
+    //  Fortran subroutine in EISPACK.
+
+    System.arraycopy(e, 1, e, 0, n - 1);
+    e[n - 1] = 0.0;
+
+    double f = 0.0;
+    double tst1 = 0.0;
+    double eps = Math.pow(2.0, -52.0);
+    for (int l = 0; l < n; l++) {
+
+      // Find small subdiagonal element
+
+      tst1 = Math.max(tst1, Math.abs(d[l]) + Math.abs(e[l]));
+      int m = l;
+      while (m < n) {
+        if (Math.abs(e[m]) <= eps * tst1) {
+          break;
+        }
+        m++;
+      }
+
+      // If m == l, d[l] is an eigenvalue,
+      // otherwise, iterate.
+
+      if (m > l) {
+        int iter = 0;
+        do {
+          iter += 1;  // (Could check iteration count here.)
+
+          // Compute implicit shift
+
+          double g = d[l];
+          double p = (d[l + 1] - g) / (2.0 * e[l]);
+          double r = Algebra.hypot(p, 1.0);
+          if (p < 0) {
+            r = -r;
+          }
+          d[l] = e[l] / (p + r);
+          d[l + 1] = e[l] * (p + r);
+          double dl1 = d[l + 1];
+          double h = g - d[l];
+          for (int i = l + 2; i < n; i++) {
+            d[i] -= h;
+          }
+          f += h;
+
+          // Implicit QL transformation.
+
+          p = d[m];
+          double c = 1.0;
+          double c2 = c;
+          double c3 = c;
+          double el1 = e[l + 1];
+          double s = 0.0;
+          double s2 = 0.0;
+          for (int i = m - 1; i >= l; i--) {
+            c3 = c2;
+            c2 = c;
+            s2 = s;
+            g = c * e[i];
+            h = c * p;
+            r = Algebra.hypot(p, e[i]);
+            e[i + 1] = s * r;
+            s = e[i] / r;
+            c = p / r;
+            p = c * d[i] - s * g;
+            d[i + 1] = h + s * (c * g + s * d[i]);
+
+            // Accumulate transformation.
+
+            for (int k = 0; k < n; k++) {
+              h = V[k][i + 1];
+              V[k][i + 1] = s * V[k][i] + c * h;
+              V[k][i] = c * V[k][i] - s * h;
+            }
+          }
+          p = -s * s2 * c3 * el1 * e[l] / dl1;
+          e[l] = s * p;
+          d[l] = c * p;
+
+          // Check for convergence.
+
+        } while (Math.abs(e[l]) > eps * tst1);
+      }
+      d[l] += f;
+      e[l] = 0.0;
+    }
+
+    // Sort eigenvalues and corresponding vectors.
+
+    for (int i = 0; i < n - 1; i++) {
+      int k = i;
+      double p = d[i];
+      for (int j = i + 1; j < n; j++) {
+        if (d[j] < p) {
+          k = j;
+          p = d[j];
+        }
+      }
+      if (k != i) {
+        d[k] = d[i];
+        d[i] = p;
+        for (int j = 0; j < n; j++) {
+          p = V[j][i];
+          V[j][i] = V[j][k];
+          V[j][k] = p;
+        }
+      }
+    }
+  }
+
+  /** Symmetric Householder reduction to tridiagonal form. */
+  private void tred2() {
+    //  This is derived from the Algol procedures tred2 by
+    //  Bowdler, Martin, Reinsch, and Wilkinson, Handbook for
+    //  Auto. Comp., Vol.ii-Linear Algebra, and the corresponding
+    //  Fortran subroutine in EISPACK.
+
+
+    System.arraycopy(V[n - 1], 0, d, 0, n);
+
+
+    // Householder reduction to tridiagonal form.
+
+    for (int i = n - 1; i > 0; i--) {
+
+      // Scale to avoid under/overflow.
+
+      double scale = 0.0;
+      for (int k = 0; k < i; k++) {
+        scale += Math.abs(d[k]);
+      }
+      double h = 0.0;
+      if (scale == 0.0) {
+        e[i] = d[i - 1];
+        for (int j = 0; j < i; j++) {
+          d[j] = V[i - 1][j];
+          V[i][j] = 0.0;
+          V[j][i] = 0.0;
+        }
+      } else {
+
+        // Generate Householder vector.
+
+        for (int k = 0; k < i; k++) {
+          d[k] /= scale;
+          h += d[k] * d[k];
+        }
+        double f = d[i - 1];
+        double g = Math.sqrt(h);
+        if (f > 0) {
+          g = -g;
+        }
+        e[i] = scale * g;
+        h -= f * g;
+        d[i - 1] = f - g;
+        for (int j = 0; j < i; j++) {
+          e[j] = 0.0;
+        }
+
+        // Apply similarity transformation to remaining columns.
+
+        for (int j = 0; j < i; j++) {
+          f = d[j];
+          V[j][i] = f;
+          g = e[j] + V[j][j] * f;
+          for (int k = j + 1; k <= i - 1; k++) {
+            g += V[k][j] * d[k];
+            e[k] += V[k][j] * f;
+          }
+          e[j] = g;
+        }
+        f = 0.0;
+        for (int j = 0; j < i; j++) {
+          e[j] /= h;
+          f += e[j] * d[j];
+        }
+        double hh = f / (h + h);
+        for (int j = 0; j < i; j++) {
+          e[j] -= hh * d[j];
+        }
+        for (int j = 0; j < i; j++) {
+          f = d[j];
+          g = e[j];
+          for (int k = j; k <= i - 1; k++) {
+            V[k][j] -= (f * e[k] + g * d[k]);
+          }
+          d[j] = V[i - 1][j];
+          V[i][j] = 0.0;
+        }
+      }
+      d[i] = h;
+    }
+
+    // Accumulate transformations.
+
+    for (int i = 0; i < n - 1; i++) {
+      V[n - 1][i] = V[i][i];
+      V[i][i] = 1.0;
+      double h = d[i + 1];
+      if (h != 0.0) {
+        for (int k = 0; k <= i; k++) {
+          d[k] = V[k][i + 1] / h;
+        }
+        for (int j = 0; j <= i; j++) {
+          double g = 0.0;
+          for (int k = 0; k <= i; k++) {
+            g += V[k][i + 1] * V[k][j];
+          }
+          for (int k = 0; k <= i; k++) {
+            V[k][j] -= g * d[k];
+          }
+        }
+      }
+      for (int k = 0; k <= i; k++) {
+        V[k][i + 1] = 0.0;
+      }
+    }
+    for (int j = 0; j < n; j++) {
+      d[j] = V[n - 1][j];
+      V[n - 1][j] = 0.0;
+    }
+    V[n - 1][n - 1] = 1.0;
+    e[0] = 0.0;
+  }
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/EigenvalueDecomposition.java
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    svn:eol-style = native

Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecomposition.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecomposition.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecomposition.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecomposition.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,123 @@
+/*
+Copyright � 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/**
+ * For an <tt>m x n</tt> matrix <tt>A</tt> with <tt>m >= n</tt>, the LU decomposition is an <tt>m x n</tt> unit lower
+ * triangular matrix <tt>L</tt>, an <tt>n x n</tt> upper triangular matrix <tt>U</tt>, and a permutation vector
+ * <tt>piv</tt> of length <tt>m</tt> so that <tt>A(piv,:) = L*U</tt>; If <tt>m < n</tt>, then <tt>L</tt> is <tt>m x
+ * m</tt> and <tt>U</tt> is <tt>m x n</tt>. <P> The LU decomposition with pivoting always exists, even if the matrix is
+ * singular, so the constructor will never fail.  The primary use of the LU decomposition is in the solution of square
+ * systems of simultaneous linear equations.  This will fail if <tt>isNonsingular()</tt> returns false.
+ *
+ * @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported.
+ */
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public class LUDecomposition implements java.io.Serializable {
+
+  private final LUDecompositionQuick quick;
+
+  /**
+   * Constructs and returns a new LU Decomposition object; The decomposed matrices can be retrieved via instance methods
+   * of the returned decomposition object.
+   *
+   * @param A Rectangular matrix
+   * @return Structure to access L, U and piv.
+   */
+  public LUDecomposition(DoubleMatrix2D A) {
+    quick = new LUDecompositionQuick(0); // zero tolerance for compatibility with Jama
+    quick.decompose(A.copy());
+  }
+
+  /**
+   * Returns the determinant, <tt>det(A)</tt>.
+   *
+   * @throws IllegalArgumentException Matrix must be square
+   */
+  public double det() {
+    return quick.det();
+  }
+
+  /**
+   * Returns pivot permutation vector as a one-dimensional double array
+   *
+   * @return (double) piv
+   */
+  private double[] getDoublePivot() {
+    return quick.getDoublePivot();
+  }
+
+  /**
+   * Returns the lower triangular factor, <tt>L</tt>.
+   *
+   * @return <tt>L</tt>
+   */
+  public DoubleMatrix2D getL() {
+    return quick.getL();
+  }
+
+  /**
+   * Returns a copy of the pivot permutation vector.
+   *
+   * @return piv
+   */
+  public int[] getPivot() {
+    return quick.getPivot().clone();
+  }
+
+  /**
+   * Returns the upper triangular factor, <tt>U</tt>.
+   *
+   * @return <tt>U</tt>
+   */
+  public DoubleMatrix2D getU() {
+    return quick.getU();
+  }
+
+  /**
+   * Returns whether the matrix is nonsingular (has an inverse).
+   *
+   * @return true if <tt>U</tt>, and hence <tt>A</tt>, is nonsingular; false otherwise.
+   */
+  public boolean isNonsingular() {
+    return quick.isNonsingular();
+  }
+
+  /**
+   * Solves <tt>A*X = B</tt>.
+   *
+   * @param B A matrix with as many rows as <tt>A</tt> and any number of columns.
+   * @return <tt>X</tt> so that <tt>L*U*X = B(piv,:)</tt>.
+   * @throws IllegalArgumentException if </tt>B.rows() != A.rows()</tt>.
+   * @throws IllegalArgumentException if A is singular, that is, if <tt>!this.isNonsingular()</tt>.
+   * @throws IllegalArgumentException if <tt>A.rows() < A.columns()</tt>.
+   */
+
+  public DoubleMatrix2D solve(DoubleMatrix2D B) {
+    DoubleMatrix2D X = B.copy();
+    quick.solve(X);
+    return X;
+  }
+
+  /**
+   * Returns a String with (propertyName, propertyValue) pairs. Useful for debugging or to quickly get the rough
+   * picture. For example,
+   * <pre>
+   * rank          : 3
+   * trace         : 0
+   * </pre>
+   */
+  public String toString() {
+    return quick.toString();
+  }
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecomposition.java
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Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecompositionQuick.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecompositionQuick.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecompositionQuick.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/LUDecompositionQuick.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,694 @@
+/*
+Copyright 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.jet.math.Mult;
+import org.apache.mahout.math.jet.math.PlusMult;
+import org.apache.mahout.math.list.IntArrayList;
+import org.apache.mahout.math.matrix.DoubleMatrix1D;
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public class LUDecompositionQuick implements java.io.Serializable {
+
+  /** Array for internal storage of decomposition. */
+  private DoubleMatrix2D LU;
+
+  /** pivot sign. */
+  private int pivsign;
+
+  /** Internal storage of pivot vector. */
+  private int[] piv;
+
+  private boolean isNonSingular;
+
+  private final Algebra algebra;
+
+  private transient double[] workDouble;
+  private transient int[] work1;
+  protected transient int[] work2;
+
+  /**
+   * Constructs and returns a new LU Decomposition object with default tolerance <tt>1.0E-9</tt> for singularity
+   * detection.
+   */
+  public LUDecompositionQuick() {
+    this(Property.DEFAULT.tolerance());
+  }
+
+  /** Constructs and returns a new LU Decomposition object which uses the given tolerance for singularity detection; */
+  public LUDecompositionQuick(double tolerance) {
+    this.algebra = new Algebra(tolerance);
+  }
+
+  /**
+   * Decomposes matrix <tt>A</tt> into <tt>L</tt> and <tt>U</tt> (in-place). Upon return <tt>A</tt> is overridden with
+   * the result <tt>LU</tt>, such that <tt>L*U = A</tt>. Uses a "left-looking", dot-product, Crout/Doolittle algorithm.
+   *
+   * @param A any matrix.
+   */
+  public void decompose(DoubleMatrix2D A) {
+    // setup
+    LU = A;
+    int m = A.rows();
+    int n = A.columns();
+
+    // setup pivot vector
+    if (this.piv == null || this.piv.length != m) {
+      this.piv = new int[m];
+    }
+    for (int i = m; --i >= 0;) {
+      piv[i] = i;
+    }
+    pivsign = 1;
+
+    if (m * n == 0) {
+      setLU(LU);
+      return; // nothing to do
+    }
+
+    //precompute and cache some views to avoid regenerating them time and again
+    DoubleMatrix1D[] LUrows = new DoubleMatrix1D[m];
+    for (int i = 0; i < m; i++) {
+      LUrows[i] = LU.viewRow(i);
+    }
+
+    IntArrayList nonZeroIndexes =
+        new IntArrayList(); // sparsity
+    DoubleMatrix1D LUcolj = LU.viewColumn(0).like();  // blocked column j
+    Mult multFunction = org.apache.mahout.math.jet.math.Mult.mult(0);
+
+    // Outer loop.
+    int CUT_OFF = 10;
+    for (int j = 0; j < n; j++) {
+      // blocking (make copy of j-th column to localize references)
+      LUcolj.assign(LU.viewColumn(j));
+
+      // sparsity detection
+      int maxCardinality = m / CUT_OFF; // == heuristic depending on speedup
+      LUcolj.getNonZeros(nonZeroIndexes, null, maxCardinality);
+      int cardinality = nonZeroIndexes.size();
+      boolean sparse = (cardinality < maxCardinality);
+
+      // Apply previous transformations.
+      for (int i = 0; i < m; i++) {
+        int kmax = Math.min(i, j);
+        double s;
+        if (sparse) {
+          s = LUrows[i].zDotProduct(LUcolj, 0, kmax, nonZeroIndexes);
+        } else {
+          s = LUrows[i].zDotProduct(LUcolj, 0, kmax);
+        }
+        double before = LUcolj.getQuick(i);
+        double after = before - s;
+        LUcolj.setQuick(i, after); // LUcolj is a copy
+        LU.setQuick(i, j, after);   // this is the original
+        if (sparse) {
+          if (before == 0 && after != 0) { // nasty bug fixed!
+            int pos = nonZeroIndexes.binarySearch(i);
+            pos = -pos - 1;
+            nonZeroIndexes.beforeInsert(pos, i);
+          }
+          if (before != 0 && after == 0) {
+            nonZeroIndexes.remove(nonZeroIndexes.binarySearch(i));
+          }
+        }
+      }
+
+      // Find pivot and exchange if necessary.
+      int p = j;
+      if (p < m) {
+        double max = Math.abs(LUcolj.getQuick(p));
+        for (int i = j + 1; i < m; i++) {
+          double v = Math.abs(LUcolj.getQuick(i));
+          if (v > max) {
+            p = i;
+            max = v;
+          }
+        }
+      }
+      if (p != j) {
+        LUrows[p].swap(LUrows[j]);
+        int k = piv[p];
+        piv[p] = piv[j];
+        piv[j] = k;
+        pivsign = -pivsign;
+      }
+
+      // Compute multipliers.
+      double jj;
+      if (j < m && (jj = LU.getQuick(j, j)) != 0.0) {
+        multFunction.setMultiplicator(1 / jj);
+        LU.viewColumn(j).viewPart(j + 1, m - (j + 1)).assign(multFunction);
+      }
+
+    }
+    setLU(LU);
+  }
+
+  /**
+   * Decomposes the banded and square matrix <tt>A</tt> into <tt>L</tt> and <tt>U</tt> (in-place). Upon return
+   * <tt>A</tt> is overridden with the result <tt>LU</tt>, such that <tt>L*U = A</tt>. Currently supports diagonal and
+   * tridiagonal matrices, all other cases fall through to {@link #decompose(DoubleMatrix2D)}.
+   *
+   * @param semiBandwidth == 1 --> A is diagonal, == 2 --> A is tridiagonal.
+   * @param A             any matrix.
+   */
+  public void decompose(DoubleMatrix2D A, int semiBandwidth) {
+    if (!algebra.property().isSquare(A) || semiBandwidth < 0 || semiBandwidth > 2) {
+      decompose(A);
+      return;
+    }
+    // setup
+    LU = A;
+    int m = A.rows();
+    int n = A.columns();
+
+    // setup pivot vector
+    if (this.piv == null || this.piv.length != m) {
+      this.piv = new int[m];
+    }
+    for (int i = m; --i >= 0;) {
+      piv[i] = i;
+    }
+    pivsign = 1;
+
+    if (m * n == 0) {
+      setLU(A);
+      return; // nothing to do
+    }
+
+    //if (semiBandwidth == 1) { // A is diagonal; nothing to do
+    if (semiBandwidth == 2) { // A is tridiagonal
+      // currently no pivoting !
+      if (n > 1) {
+        A.setQuick(1, 0, A.getQuick(1, 0) / A.getQuick(0, 0));
+      }
+
+      for (int i = 1; i < n; i++) {
+        double ei = A.getQuick(i, i) - A.getQuick(i, i - 1) * A.getQuick(i - 1, i);
+        A.setQuick(i, i, ei);
+        if (i < n - 1) {
+          A.setQuick(i + 1, i, A.getQuick(i + 1, i) / ei);
+        }
+      }
+    }
+    setLU(A);
+  }
+
+  /**
+   * Returns the determinant, <tt>det(A)</tt>.
+   *
+   * @throws IllegalArgumentException if <tt>A.rows() != A.columns()</tt> (Matrix must be square).
+   */
+  public double det() {
+    int m = m();
+    int n = n();
+    if (m != n) {
+      throw new IllegalArgumentException("Matrix must be square.");
+    }
+
+    if (!isNonsingular()) {
+      return 0;
+    } // avoid rounding errors
+
+    double det = (double) pivsign;
+    for (int j = 0; j < n; j++) {
+      det *= LU.getQuick(j, j);
+    }
+    return det;
+  }
+
+  /**
+   * Returns pivot permutation vector as a one-dimensional double array
+   *
+   * @return (double) piv
+   */
+  protected double[] getDoublePivot() {
+    int m = m();
+    double[] vals = new double[m];
+    for (int i = 0; i < m; i++) {
+      vals[i] = (double) piv[i];
+    }
+    return vals;
+  }
+
+  /**
+   * Returns the lower triangular factor, <tt>L</tt>.
+   *
+   * @return <tt>L</tt>
+   */
+  public DoubleMatrix2D getL() {
+    return lowerTriangular(LU.copy());
+  }
+
+  /**
+   * Returns a copy of the combined lower and upper triangular factor, <tt>LU</tt>.
+   *
+   * @return <tt>LU</tt>
+   */
+  public DoubleMatrix2D getLU() {
+    return LU.copy();
+  }
+
+  /**
+   * Returns the pivot permutation vector (not a copy of it).
+   *
+   * @return piv
+   */
+  public int[] getPivot() {
+    return piv;
+  }
+
+  /**
+   * Returns the upper triangular factor, <tt>U</tt>.
+   *
+   * @return <tt>U</tt>
+   */
+  public DoubleMatrix2D getU() {
+    return upperTriangular(LU.copy());
+  }
+
+  /**
+   * Returns whether the matrix is nonsingular (has an inverse).
+   *
+   * @return true if <tt>U</tt>, and hence <tt>A</tt>, is nonsingular; false otherwise.
+   */
+  public boolean isNonsingular() {
+    return isNonSingular;
+  }
+
+  /**
+   * Returns whether the matrix is nonsingular.
+   *
+   * @return true if <tt>matrix</tt> is nonsingular; false otherwise.
+   */
+  protected boolean isNonsingular(DoubleMatrix2D matrix) {
+    int m = matrix.rows();
+    int n = matrix.columns();
+    double epsilon = algebra.property().tolerance(); // consider numerical instability
+    for (int j = Math.min(n, m); --j >= 0;) {
+      //if (matrix.getQuick(j,j) == 0) return false;
+      if (Math.abs(matrix.getQuick(j, j)) <= epsilon) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Modifies the matrix to be a lower triangular matrix. <p> <b>Examples:</b> <table border="0"> <tr nowrap> <td
+   * valign="top">3 x 5 matrix:<br> 9, 9, 9, 9, 9<br> 9, 9, 9, 9, 9<br> 9, 9, 9, 9, 9 </td> <td
+   * align="center">triang.Upper<br> ==></td> <td valign="top">3 x 5 matrix:<br> 9, 9, 9, 9, 9<br> 0, 9, 9, 9, 9<br> 0,
+   * 0, 9, 9, 9</td> </tr> <tr nowrap> <td valign="top">5 x 3 matrix:<br> 9, 9, 9<br> 9, 9, 9<br> 9, 9, 9<br> 9, 9,
+   * 9<br> 9, 9, 9 </td> <td align="center">triang.Upper<br> ==></td> <td valign="top">5 x 3 matrix:<br> 9, 9, 9<br> 0,
+   * 9, 9<br> 0, 0, 9<br> 0, 0, 0<br> 0, 0, 0</td> </tr> <tr nowrap> <td valign="top">3 x 5 matrix:<br> 9, 9, 9, 9,
+   * 9<br> 9, 9, 9, 9, 9<br> 9, 9, 9, 9, 9 </td> <td align="center">triang.Lower<br> ==></td> <td valign="top">3 x 5
+   * matrix:<br> 1, 0, 0, 0, 0<br> 9, 1, 0, 0, 0<br> 9, 9, 1, 0, 0</td> </tr> <tr nowrap> <td valign="top">5 x 3
+   * matrix:<br> 9, 9, 9<br> 9, 9, 9<br> 9, 9, 9<br> 9, 9, 9<br> 9, 9, 9 </td> <td align="center">triang.Lower<br>
+   * ==></td> <td valign="top">5 x 3 matrix:<br> 1, 0, 0<br> 9, 1, 0<br> 9, 9, 1<br> 9, 9, 9<br> 9, 9, 9</td> </tr>
+   * </table>
+   *
+   * @return <tt>A</tt> (for convenience only).
+   */
+  protected DoubleMatrix2D lowerTriangular(DoubleMatrix2D A) {
+    int rows = A.rows();
+    int columns = A.columns();
+    int min = Math.min(rows, columns);
+    for (int r = min; --r >= 0;) {
+      for (int c = min; --c >= 0;) {
+        if (r < c) {
+          A.setQuick(r, c, 0);
+        } else if (r == c) {
+          A.setQuick(r, c, 1);
+        }
+      }
+    }
+    if (columns > rows) {
+      A.viewPart(0, min, rows, columns - min).assign(0);
+    }
+
+    return A;
+  }
+
+  /**
+   *
+   */
+  protected int m() {
+    return LU.rows();
+  }
+
+  /**
+   *
+   */
+  protected int n() {
+    return LU.columns();
+  }
+
+  /**
+   * Sets the combined lower and upper triangular factor, <tt>LU</tt>. The parameter is not checked; make sure it is
+   * indeed a proper LU decomposition.
+   */
+  public void setLU(DoubleMatrix2D LU) {
+    this.LU = LU;
+    this.isNonSingular = isNonsingular(LU);
+  }
+
+  /**
+   * Solves the system of equations <tt>A*X = B</tt> (in-place). Upon return <tt>B</tt> is overridden with the result
+   * <tt>X</tt>, such that <tt>L*U*X = B(piv)</tt>.
+   *
+   * @param B A vector with <tt>B.size() == A.rows()</tt>.
+   * @throws IllegalArgumentException if </tt>B.size() != A.rows()</tt>.
+   * @throws IllegalArgumentException if A is singular, that is, if <tt>!isNonsingular()</tt>.
+   * @throws IllegalArgumentException if <tt>A.rows() < A.columns()</tt>.
+   */
+  public void solve(DoubleMatrix1D B) {
+    algebra.property().checkRectangular(LU);
+    int m = m();
+    int n = n();
+    if (B.size() != m) {
+      throw new IllegalArgumentException("Matrix dimensions must agree.");
+    }
+    if (!this.isNonsingular()) {
+      throw new IllegalArgumentException("Matrix is singular.");
+    }
+
+
+    // right hand side with pivoting
+    // Matrix Xmat = B.getMatrix(piv,0,nx-1);
+    if (this.workDouble == null || this.workDouble.length < m) {
+      this.workDouble = new double[m];
+    }
+    algebra.permute(B, this.piv, this.workDouble);
+
+    if (m * n == 0) {
+      return;
+    } // nothing to do
+
+    // Solve L*Y = B(piv,:)
+    for (int k = 0; k < n; k++) {
+      double f = B.getQuick(k);
+      if (f != 0) {
+        for (int i = k + 1; i < n; i++) {
+          // B[i] -= B[k]*LU[i][k];
+          double v = LU.getQuick(i, k);
+          if (v != 0) {
+            B.setQuick(i, B.getQuick(i) - f * v);
+          }
+        }
+      }
+    }
+
+    // Solve U*B = Y;
+    for (int k = n - 1; k >= 0; k--) {
+      // B[k] /= LU[k,k]
+      B.setQuick(k, B.getQuick(k) / LU.getQuick(k, k));
+      double f = B.getQuick(k);
+      if (f != 0) {
+        for (int i = 0; i < k; i++) {
+          // B[i] -= B[k]*LU[i][k];
+          double v = LU.getQuick(i, k);
+          if (v != 0) {
+            B.setQuick(i, B.getQuick(i) - f * v);
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Solves the system of equations <tt>A*X = B</tt> (in-place). Upon return <tt>B</tt> is overridden with the result
+   * <tt>X</tt>, such that <tt>L*U*X = B(piv,:)</tt>.
+   *
+   * @param B A matrix with as many rows as <tt>A</tt> and any number of columns.
+   * @throws IllegalArgumentException if </tt>B.rows() != A.rows()</tt>.
+   * @throws IllegalArgumentException if A is singular, that is, if <tt>!isNonsingular()</tt>.
+   * @throws IllegalArgumentException if <tt>A.rows() < A.columns()</tt>.
+   */
+  public void solve(DoubleMatrix2D B) {
+    algebra.property().checkRectangular(LU);
+    int m = m();
+    int n = n();
+    if (B.rows() != m) {
+      throw new IllegalArgumentException("Matrix row dimensions must agree.");
+    }
+    if (!this.isNonsingular()) {
+      throw new IllegalArgumentException("Matrix is singular.");
+    }
+
+
+    // right hand side with pivoting
+    // Matrix Xmat = B.getMatrix(piv,0,nx-1);
+    if (this.work1 == null || this.work1.length < m) {
+      this.work1 = new int[m];
+    }
+    //if (this.work2 == null || this.work2.length < m) this.work2 = new int[m];
+    algebra.permuteRows(B, this.piv, this.work1);
+
+    if (m * n == 0) {
+      return;
+    } // nothing to do
+    int nx = B.columns();
+
+    //precompute and cache some views to avoid regenerating them time and again
+    DoubleMatrix1D[] Brows = new DoubleMatrix1D[n];
+    for (int k = 0; k < n; k++) {
+      Brows[k] = B.viewRow(k);
+    }
+
+    // transformations
+    Mult div = org.apache.mahout.math.jet.math.Mult.div(0);
+    PlusMult minusMult = org.apache.mahout.math.jet.math.PlusMult.minusMult(0);
+
+    IntArrayList nonZeroIndexes =
+        new IntArrayList(); // sparsity
+    DoubleMatrix1D Browk = org.apache.mahout.math.matrix.DoubleFactory1D.dense.make(nx); // blocked row k
+
+    // Solve L*Y = B(piv,:)
+    int CUT_OFF = 10;
+    for (int k = 0; k < n; k++) {
+      // blocking (make copy of k-th row to localize references)
+      Browk.assign(Brows[k]);
+
+      // sparsity detection
+      int maxCardinality = nx / CUT_OFF; // == heuristic depending on speedup
+      Browk.getNonZeros(nonZeroIndexes, null, maxCardinality);
+      int cardinality = nonZeroIndexes.size();
+      boolean sparse = (cardinality < maxCardinality);
+
+      for (int i = k + 1; i < n; i++) {
+        //for (int j = 0; j < nx; j++) B[i][j] -= B[k][j]*LU[i][k];
+        //for (int j = 0; j < nx; j++) B.set(i,j, B.get(i,j) - B.get(k,j)*LU.get(i,k));
+
+        minusMult.setMultiplicator(-LU.getQuick(i, k));
+        if (minusMult.getMultiplicator() != 0) {
+          if (sparse) {
+            Brows[i].assign(Browk, minusMult, nonZeroIndexes);
+          } else {
+            Brows[i].assign(Browk, minusMult);
+          }
+        }
+      }
+    }
+
+    // Solve U*B = Y;
+    for (int k = n - 1; k >= 0; k--) {
+      // for (int j = 0; j < nx; j++) B[k][j] /= LU[k][k];
+      // for (int j = 0; j < nx; j++) B.set(k,j, B.get(k,j) / LU.get(k,k));
+      div.setMultiplicator(1 / LU.getQuick(k, k));
+      Brows[k].assign(div);
+
+      // blocking
+      if (Browk == null) {
+        Browk = org.apache.mahout.math.matrix.DoubleFactory1D.dense.make(B.columns());
+      }
+      Browk.assign(Brows[k]);
+
+      // sparsity detection
+      int maxCardinality = nx / CUT_OFF; // == heuristic depending on speedup
+      Browk.getNonZeros(nonZeroIndexes, null, maxCardinality);
+      int cardinality = nonZeroIndexes.size();
+      boolean sparse = (cardinality < maxCardinality);
+
+      //Browk.getNonZeros(nonZeroIndexes,null);
+      //boolean sparse = nonZeroIndexes.size() < nx/10;
+
+      for (int i = 0; i < k; i++) {
+        // for (int j = 0; j < nx; j++) B[i][j] -= B[k][j]*LU[i][k];
+        // for (int j = 0; j < nx; j++) B.set(i,j, B.get(i,j) - B.get(k,j)*LU.get(i,k));
+
+        minusMult.setMultiplicator(-LU.getQuick(i, k));
+        if (minusMult.getMultiplicator() != 0) {
+          if (sparse) {
+            Brows[i].assign(Browk, minusMult, nonZeroIndexes);
+          } else {
+            Brows[i].assign(Browk, minusMult);
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Solves <tt>A*X = B</tt>.
+   *
+   * @param B A matrix with as many rows as <tt>A</tt> and any number of columns.
+   * @return <tt>X</tt> so that <tt>L*U*X = B(piv,:)</tt>.
+   * @throws IllegalArgumentException if </tt>B.rows() != A.rows()</tt>.
+   * @throws IllegalArgumentException if A is singular, that is, if <tt>!this.isNonsingular()</tt>.
+   * @throws IllegalArgumentException if <tt>A.rows() < A.columns()</tt>.
+   */
+  private void solveOld(DoubleMatrix2D B) {
+    algebra.property().checkRectangular(LU);
+    int m = m();
+    int n = n();
+    if (B.rows() != m) {
+      throw new IllegalArgumentException("Matrix row dimensions must agree.");
+    }
+    if (!this.isNonsingular()) {
+      throw new IllegalArgumentException("Matrix is singular.");
+    }
+
+    // Copy right hand side with pivoting
+    int nx = B.columns();
+
+    if (this.work1 == null || this.work1.length < m) {
+      this.work1 = new int[m];
+    }
+    //if (this.work2 == null || this.work2.length < m) this.work2 = new int[m];
+    algebra.permuteRows(B, this.piv, this.work1);
+
+    // Solve L*Y = B(piv,:) --> Y (Y is modified B)
+    for (int k = 0; k < n; k++) {
+      for (int i = k + 1; i < n; i++) {
+        double mult = LU.getQuick(i, k);
+        if (mult != 0) {
+          for (int j = 0; j < nx; j++) {
+            //B[i][j] -= B[k][j]*LU[i,k];
+            B.setQuick(i, j, B.getQuick(i, j) - B.getQuick(k, j) * mult);
+          }
+        }
+      }
+    }
+    // Solve U*X = Y; --> X (X is modified B)
+    for (int k = n - 1; k >= 0; k--) {
+      double mult = 1 / LU.getQuick(k, k);
+      if (mult != 1) {
+        for (int j = 0; j < nx; j++) {
+          //B[k][j] /= LU[k][k];
+          B.setQuick(k, j, B.getQuick(k, j) * mult);
+        }
+      }
+      for (int i = 0; i < k; i++) {
+        mult = LU.getQuick(i, k);
+        if (mult != 0) {
+          for (int j = 0; j < nx; j++) {
+            //B[i][j] -= B[k][j]*LU[i][k];
+            B.setQuick(i, j, B.getQuick(i, j) - B.getQuick(k, j) * mult);
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Returns a String with (propertyName, propertyValue) pairs. Useful for debugging or to quickly get the rough
+   * picture. For example,
+   * <pre>
+   * rank          : 3
+   * trace         : 0
+   * </pre>
+   */
+  public String toString() {
+    StringBuilder buf = new StringBuilder();
+
+    buf.append("-----------------------------------------------------------------------------\n");
+    buf.append("LUDecompositionQuick(A) --> isNonSingular(A), det(A), pivot, L, U, inverse(A)\n");
+    buf.append("-----------------------------------------------------------------------------\n");
+
+    buf.append("isNonSingular = ");
+    String unknown = "Illegal operation or error: ";
+    try {
+      buf.append(String.valueOf(this.isNonsingular()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\ndet = ");
+    try {
+      buf.append(String.valueOf(this.det()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\npivot = ");
+    try {
+      buf.append(String.valueOf(new IntArrayList(this.getPivot())));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\nL = ");
+    try {
+      buf.append(String.valueOf(this.getL()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\nU = ");
+    try {
+      buf.append(String.valueOf(this.getU()));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    buf.append("\n\ninverse(A) = ");
+    DoubleMatrix2D identity = org.apache.mahout.math.matrix.DoubleFactory2D.dense.identity(LU.rows());
+    try {
+      this.solve(identity);
+      buf.append(String.valueOf(identity));
+    }
+    catch (IllegalArgumentException exc) {
+      buf.append(unknown).append(exc.getMessage());
+    }
+
+    return buf.toString();
+  }
+
+  /**
+   * Modifies the matrix to be an upper triangular matrix.
+   *
+   * @return <tt>A</tt> (for convenience only).
+   */
+  protected DoubleMatrix2D upperTriangular(DoubleMatrix2D A) {
+    int rows = A.rows();
+    int columns = A.columns();
+    int min = Math.min(rows, columns);
+    for (int r = min; --r >= 0;) {
+      for (int c = min; --c >= 0;) {
+        if (r > c) {
+          A.setQuick(r, c, 0);
+        }
+      }
+    }
+    if (columns < rows) {
+      A.viewPart(min, 0, rows - min, columns).assign(0);
+    }
+
+    return A;
+  }
+
+}

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Added: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Matrix2DMatrix2DFunction.java
URL: http://svn.apache.org/viewvc/lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Matrix2DMatrix2DFunction.java?rev=891983&view=auto
==============================================================================
--- lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Matrix2DMatrix2DFunction.java (added)
+++ lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Matrix2DMatrix2DFunction.java Thu Dec 17 23:22:16 2009
@@ -0,0 +1,25 @@
+/*
+Copyright 1999 CERN - European Organization for Nuclear Research.
+Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose 
+is hereby granted without fee, provided that the above copyright notice appear in all copies and 
+that both that copyright notice and this permission notice appear in supporting documentation. 
+CERN makes no representations about the suitability of this software for any purpose. 
+It is provided "as is" without expressed or implied warranty.
+*/
+package org.apache.mahout.math.matrix.linalg;
+
+import org.apache.mahout.math.matrix.DoubleMatrix2D;
+
+/** @deprecated until unit tests are in place.  Until this time, this class/interface is unsupported. */
+@Deprecated
+public interface Matrix2DMatrix2DFunction {
+
+  /**
+   * Applies a function to two arguments.
+   *
+   * @param x the first argument passed to the function.
+   * @param y the second argument passed to the function.
+   * @return the result of the function.
+   */
+  double apply(DoubleMatrix2D x, DoubleMatrix2D y);
+}

Propchange: lucene/mahout/trunk/math/src/main/java/org/apache/mahout/math/matrix/linalg/Matrix2DMatrix2DFunction.java
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