[commons-math] 02/02: Use Complex.ZERO.

[ah...@apache.org]

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aherbert pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-math.git

commit 0bf33a4fc13474835414a24c80d50cc7710eaf49
Author: aherbert <ah...@apache.org>
AuthorDate: Fri Jul 15 17:28:33 2022 +0100

    Use Complex.ZERO.
    
    This does not change the equals comparison. Note that this will not
    detect sign differences, e.g. (0.0, 0.0) == (-0.0, 0.0) and a tolerance
    may be required for more robustness.
---
 .../apache/commons/math4/legacy/analysis/solvers/LaguerreSolver.java   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/analysis/solvers/LaguerreSolver.java b/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/analysis/solvers/LaguerreSolver.java
index e0dcc37b7..24afe0b7f 100644
--- a/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/analysis/solvers/LaguerreSolver.java
+++ b/commons-math-legacy/src/main/java/org/apache/commons/math4/legacy/analysis/solvers/LaguerreSolver.java
@@ -368,7 +368,8 @@ public class LaguerreSolver extends AbstractPolynomialSolver {
                 final Complex denominator = dplus.abs() > dminus.abs() ? dplus : dminus;
                 // Perturb z if denominator is zero, for instance,
                 // p(x) = x^3 + 1, z = 0.
-                if (denominator.equals(Complex.ofCartesian(0.0, 0.0))) {
+                // This uses exact equality to zero. A tolerance may be required here.
+                if (denominator.equals(Complex.ZERO)) {
                     z = z.add(Complex.ofCartesian(absoluteAccuracy, absoluteAccuracy));
                     oldz = Complex.ofCartesian(Double.POSITIVE_INFINITY,
                                        Double.POSITIVE_INFINITY);