From fdf112839298f331fde75a988dd2fee8a024d753 Mon Sep 17 00:00:00 2001
From: villberg <villberg@ac1ea38d-2e2b-0410-8846-a27921b304fc>
Date: Sun, 8 Jun 2014 20:46:32 +0000
Subject: [PATCH] Fixed NPE when initial equations are not defined for
 enumerated stocks. This is just a work-around. Modelica code generation
 should be fixed to include the proper initial equations. Stocks are now
 initialized to 0. refs #4932

git-svn-id: https://www.simantics.org/svn/simantics/sysdyn/trunk@29598 ac1ea38d-2e2b-0410-8846-a27921b304fc
---
 .../src/fi/semantum/sysdyn/solver/Derivate.java           | 2 ++
 .../src/fi/semantum/sysdyn/solver/Environment.java        | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Derivate.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Derivate.java
index 131ca742..7d26af56 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Derivate.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Derivate.java
@@ -29,6 +29,8 @@ public class Derivate implements IExpression {
 		Environment environment = (Environment)_environment;
 //		Double old = (Double)environment.getValue(variable.name + variable.subscriptKey());
 		Double old = (Double)environment.getValue(variable.base.index(_environment, subscripts));
+		// FIXME: should not be fixed like this
+		if(old == null) old = 0.0;
 		return old+environment.step*(Double)e.evaluate(environment);
 	}
 	
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Environment.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Environment.java
index 01df0c3a..90f84a9b 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Environment.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Environment.java
@@ -483,8 +483,12 @@ final public class Environment implements IEnvironment, ISystem {
 		for (int i = 0; i < model.derivativeArray.length; i++) {
 			Variable v = model.derivativeArray[i].target;
 			if(!used.add(v.base.name)) continue;
-			for(int index=0;index<v.base.dimension();index++)
-				valueArray[offset++] = (Double)getValue(v.base.index(this, null)+index);
+			for(int index=0;index<v.base.dimension();index++) {
+				Double value = (Double)getValue(v.base.index(this, null)+index);
+				// FIXME: should not be fixed like this
+				if(value == null) value = 0.0;
+				valueArray[offset++] = value;
+			}
 		}
 		
 		// NOTE: there is room for optimization as parameter values that do not
-- 
2.47.1