Changed default integration rule to backward Euler. Ensured array size is set to 0 when effective concentration plot variable is set to float.

Author: SteveMaas1978

FEBioChem/FEBioChemPlot.cpp

@@ -41,6 +41,7 @@ bool FEChemPlotEffectiveConcentration::SetFilter(const char* sz)
 	if (m_nsol >= 0)
 	{
 		SetVarType(PLT_FLOAT);
+		SetArraySize(0);
 	}
 	return (m_nsol != -1);
 }

FEBioChem/FENLReactionDiffusionSolver.cpp

@@ -30,7 +30,7 @@ FEChemNLReactionDiffusionSolver::FEChemNLReactionDiffusionSolver(FEModel* fem) :
 	// alpha = 0    --> Forward Euler (conditionally stable)
 	// alpha = 0.5  --> Trapezoidal rule (unconditionally stable, second-order accurate)
 	// alpha = 1.0  --> Backward Euler (unconditionally stable, first-order accurate)
-	m_alpha = 0.5;
+	m_alpha = 1.0; // we choose 1, eventhough it's less accurate, it doesn't cause oscillations
 
 	// we'll need a non-symmetric stiffness matrix
 	m_msymm = REAL_UNSYMMETRIC;