svn commit: r1403591 - /commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java

[er...@apache.org]

Author: erans
Date: Tue Oct 30 00:38:44 2012
New Revision: 1403591

URL: http://svn.apache.org/viewvc?rev=1403591&view=rev
Log:
Use the "isSymmetric" utility method from "MatrixUtils" (copied from
"EigenDecomposition" in MATH-884).

Modified:
    commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java

Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java?rev=1403591&r1=1403590&r2=1403591&view=diff
==============================================================================
--- commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java (original)
+++ commons/proper/math/trunk/src/main/java/org/apache/commons/math3/linear/EigenDecomposition.java Tue Oct 30 00:38:44 2012
@@ -115,7 +115,8 @@ public class EigenDecomposition {
      */
     public EigenDecomposition(final RealMatrix matrix)
         throws MathArithmeticException {
-        isSymmetric = isSymmetric(matrix, false);
+        final double symTol = 10 * matrix.getRowDimension() * matrix.getColumnDimension() * Precision.EPSILON;
+        isSymmetric = MatrixUtils.isSymmetric(matrix, symTol);
         if (isSymmetric) {
             transformToTridiagonal(matrix);
             findEigenVectors(transformer.getQ().getData());
@@ -182,37 +183,6 @@ public class EigenDecomposition {
     }
 
     /**
-     * Check if a matrix is symmetric.
-     *
-     * @param matrix Matrix to check.
-     * @param raiseException If {@code true}, the method will throw an
-     * exception if {@code matrix} is not symmetric.
-     * @return {@code true} if {@code matrix} is symmetric.
-     * @throws NonSymmetricMatrixException if the matrix is not symmetric and
-     * {@code raiseException} is {@code true}.
-     */
-    private boolean isSymmetric(final RealMatrix matrix,
-                                boolean raiseException) {
-        final int rows = matrix.getRowDimension();
-        final int columns = matrix.getColumnDimension();
-        final double eps = 10 * rows * columns * Precision.EPSILON;
-        for (int i = 0; i < rows; ++i) {
-            for (int j = i + 1; j < columns; ++j) {
-                final double mij = matrix.getEntry(i, j);
-                final double mji = matrix.getEntry(j, i);
-                if (FastMath.abs(mij - mji) >
-                    (FastMath.max(FastMath.abs(mij), FastMath.abs(mji)) * eps)) {
-                    if (raiseException) {
-                        throw new NonSymmetricMatrixException(i, j, eps);
-                    }
-                    return false;
-                }
-            }
-        }
-        return true;
-    }
-
-    /**
      * Gets the matrix V of the decomposition.
      * V is an orthogonal matrix, i.e. its transpose is also its inverse.
      * The columns of V are the eigenvectors of the original matrix.