Merge Pull Request #4700 from trilinos/Trilinos/tempus-fix-divide-by-…

…zero-3698 Automatically Merged using Trilinos Pull Request AutoTester PR Title: Tempus: Fix Divide by Zero PR Author: ccober6
trilinos · Mar 26, 2019 · 9330de5 · 9330de5
2 parents 022d09d + a739ab8
commit 9330de5
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/packages/tempus/src/Tempus_StepperImplicit_impl.hpp b/packages/tempus/src/Tempus_StepperImplicit_impl.hpp
@@ -212,7 +212,11 @@ void StepperImplicit<Scalar>::setInitialConditions(
 
     this->evaluateImplicitODE(f, x, xDot, time, p);
 
-    Scalar reldiff = Thyra::norm(*f)/Thyra::norm(*x);
+    Scalar normX = Thyra::norm(*x);
+    Scalar reldiff = Scalar(0.0);
+    if (normX == Scalar(0.0)) reldiff = Thyra::norm(*f);
+    else reldiff = Thyra::norm(*f)/normX;
+
     Scalar eps = Scalar(100.0)*std::abs(Teuchos::ScalarTraits<Scalar>::eps());
     if (reldiff > eps) {
       RCP<Teuchos::FancyOStream> out = this->getOStream();