Changeset e21d55 for src/Dynamics/ForceAnnealing.hpp

Timestamp:

Apr 10, 2018, 6:43:12 AM (7 years ago)

Author:

Frederik Heber <frederik.heber@…>

Branches:

AutomationFragmentation_failures, Candidate_v1.6.1, ChemicalSpaceEvaluator, Enhanced_StructuralOptimization_continued, Exclude_Hydrogens_annealWithBondGraph, ForceAnnealing_with_BondGraph, ForceAnnealing_with_BondGraph_contraction-expansion, Gui_displays_atomic_force_velocity, PythonUI_with_named_parameters, StoppableMakroAction, TremoloParser_IncreasedPrecision

Children:

d3e1d5

Parents:

075357

git-author:

Frederik Heber <frederik.heber@…> (09/12/17 09:55:19)

git-committer:

Frederik Heber <frederik.heber@…> (04/10/18 06:43:12)

Message:

FIX: annealWithBondgraph() did not check for zero GradientDifference.

• extracted Barzilai-Borwein stepwidth into extra function.

File:

• src/Dynamics/ForceAnnealing.hpp (modified) (3 diffs)

src/Dynamics/ForceAnnealing.hpp

@@ -123 +123 @@
   }
 
+  /** Helper function to calculate the Barzilai-Borwein stepwidth.
+   *
+   * \param _PositionDifference difference in position between current and last step
+   * \param _GradientDifference difference in gradient between current and last step
+   * \return step width according to Barzilai-Borwein
+   */
+  double getBarzilaiBorweinStepwidth(const Vector &_PositionDifference, const Vector &_GradientDifference)
+  {
+    double stepwidth = 0.;
+    if (_GradientDifference.NormSquared() > MYEPSILON)
+      stepwidth = fabs(_PositionDifference.ScalarProduct(_GradientDifference))/
+          _GradientDifference.NormSquared();
+    if (fabs(stepwidth) < 1e-10) {
+      // dont' warn in first step, deltat usage normal
+      if (currentStep != 1)
+        ELOG(1, "INFO: Barzilai-Borwein stepwidth is zero, using deltat " << currentDeltat << " instead.");
+      stepwidth = currentDeltat;
+    }
+    return stepwidth;
+  }
+
   /** Performs Gradient optimization on the atoms.
    *
@@ -150 +171 @@
 
       // we use Barzilai-Borwein update with position reversed to get descent
-      const Vector PositionDifference = currentPosition - oldPosition;
-      const Vector GradientDifference = (currentGradient - oldGradient);
-      double stepwidth = 0.;
-      if (GradientDifference.Norm() > MYEPSILON)
-        stepwidth = fabs(PositionDifference.ScalarProduct(GradientDifference))/
-            GradientDifference.NormSquared();
-      if (fabs(stepwidth) < 1e-10) {
-        // dont' warn in first step, deltat usage normal
-        if (currentStep != 1)
-          ELOG(1, "INFO: Barzilai-Borwein stepwidth is zero, using deltat " << currentDeltat << " instead.");
-        stepwidth = currentDeltat;
-      }
+      const double stepwidth = getBarzilaiBorweinStepwidth(
+          currentPosition - oldPosition, currentGradient - oldGradient);
       Vector PositionUpdate = stepwidth * currentGradient;
       LOG(3, "DEBUG: Update would be " << stepwidth << "*" << currentGradient << " = " << PositionUpdate);
@@ -232 +243 @@
 
       // we use Barzilai-Borwein update with position reversed to get descent
-      const Vector GradientDifference = (currentGradient - oldGradient);
-      const double stepwidth =
-          fabs((currentPosition - oldPosition).ScalarProduct(GradientDifference))/
-          GradientDifference.NormSquared();
-      Vector PositionUpdate = stepwidth * currentGradient;
-      if (fabs(stepwidth) < 1e-10) {
-        // dont' warn in first step, deltat usage normal
-        if (currentStep != 1)
-          ELOG(1, "INFO: Barzilai-Borwein stepwidth is zero, using deltat " << currentDeltat << " instead.");
-        PositionUpdate = currentDeltat * currentGradient;
-      }
-      LOG(3, "DEBUG: Update would be " << PositionUpdate);
+      const double stepwidth = getBarzilaiBorweinStepwidth(
+          currentPosition - oldPosition, currentGradient - oldGradient);
+      const Vector PositionUpdate = stepwidth * currentGradient;
+      LOG(3, "DEBUG: Update would be " << stepwidth << "*" << currentGradient << " = " << PositionUpdate);
 
 //      // add update to central atom