MATH-956

Replaced hard-coded numbers with constants from class "Precision". git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1461197 13f79535-47bb-0310-9956-ffa450edef68
apache · Mar 26, 2013 · bb8a2a6 · bb8a2a6
1 parent e4c91be
commit bb8a2a6
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
@@ -55,6 +55,9 @@ This is a minor release: It combines bug fixes and new features.
   Changes to existing features were made in a backwards-compatible
   way such as to allow drop-in replacement of the v3.1[.1] JAR file.
 ">
+      <action dev="erans" type="update" issue="MATH-956">
+        Replaced hard-coded numbers in "LevenbergMarquardtOptimizer".
+      </action>
       <action dev="luc" type="update" issue="MATH-955" due-to="Evan Ward">
         Fixed loading of test file when path contains a space.
       </action>

diff --git a/...org/apache/commons/math3/optim/nonlinear/vector/jacobian/LevenbergMarquardtOptimizer.java b/...org/apache/commons/math3/optim/nonlinear/vector/jacobian/LevenbergMarquardtOptimizer.java
@@ -112,6 +112,8 @@
  */
 public class LevenbergMarquardtOptimizer
     extends AbstractLeastSquaresOptimizer {
+    /** Twice the "epsilon machine". */
+    private static final double TWO_EPS = 2 * Precision.EPSILON;
     /** Number of solved point. */
     private int solvedCols;
     /** Diagonal elements of the R matrix in the Q.R. decomposition. */
@@ -518,14 +520,15 @@ protected PointVectorValuePair doOptimize() {
                 }
 
                 // tests for termination and stringent tolerances
-                // (2.2204e-16 is the machine epsilon for IEEE754)
-                if ((FastMath.abs(actRed) <= 2.2204e-16) && (preRed <= 2.2204e-16) && (ratio <= 2.0)) {
+                if (FastMath.abs(actRed) <= TWO_EPS &&
+                    preRed <= TWO_EPS &&
+                    ratio <= 2.0) {
                     throw new ConvergenceException(LocalizedFormats.TOO_SMALL_COST_RELATIVE_TOLERANCE,
                                                    costRelativeTolerance);
-                } else if (delta <= 2.2204e-16 * xNorm) {
+                } else if (delta <= TWO_EPS * xNorm) {
                     throw new ConvergenceException(LocalizedFormats.TOO_SMALL_PARAMETERS_RELATIVE_TOLERANCE,
                                                    parRelativeTolerance);
-                } else if (maxCosine <= 2.2204e-16)  {
+                } else if (maxCosine <= TWO_EPS) {
                     throw new ConvergenceException(LocalizedFormats.TOO_SMALL_ORTHOGONALITY_TOLERANCE,
                                                    orthoTolerance);
                 }
@@ -630,8 +633,7 @@ private void determineLMParameter(double[] qy, double delta, double[] diag,
         double gNorm = FastMath.sqrt(sum2);
         double paru = gNorm / delta;
         if (paru == 0) {
-            // 2.2251e-308 is the smallest positive real for IEE754
-            paru = 2.2251e-308 / FastMath.min(delta, 0.1);
+            paru = Precision.SAFE_MIN / FastMath.min(delta, 0.1);
         }
 
         // if the input par lies outside of the interval (parl,paru),
@@ -645,7 +647,7 @@ private void determineLMParameter(double[] qy, double delta, double[] diag,
 
             // evaluate the function at the current value of lmPar
             if (lmPar == 0) {
-                lmPar = FastMath.max(2.2251e-308, 0.001 * paru);
+                lmPar = FastMath.max(Precision.SAFE_MIN, 0.001 * paru);
             }
             double sPar = FastMath.sqrt(lmPar);
             for (int j = 0; j < solvedCols; ++j) {