From 7df05015276ebed35552e9fbaa35148a1d10819f Mon Sep 17 00:00:00 2001
From: villberg <villberg@ac1ea38d-2e2b-0410-8846-a27921b304fc>
Date: Wed, 3 Sep 2014 12:24:45 +0000
Subject: [PATCH] Multiple bugfixes for project model refs #5224

git-svn-id: https://www.simantics.org/svn/simantics/sysdyn/trunk@30195 ac1ea38d-2e2b-0410-8846-a27921b304fc
---
 .../fi/semantum/sysdyn/solver/Addition.java   |  11 +-
 .../src/fi/semantum/sysdyn/solver/Array.java  | 103 ++++++------------
 .../fi/semantum/sysdyn/solver/Derivate.java   |  25 +++--
 .../fi/semantum/sysdyn/solver/Division.java   |  23 ++--
 .../sysdyn/solver/ElementwiseDivision.java    |  61 ++++++-----
 .../sysdyn/solver/ElementwisePower.java       |  53 ++++++---
 .../sysdyn/solver/ElementwiseProduct.java     |  63 +++++------
 .../semantum/sysdyn/solver/Environment.java   |  90 +++++++++++----
 .../fi/semantum/sysdyn/solver/Function.java   |   2 +-
 .../semantum/sysdyn/solver/GreaterThan.java   |   4 +-
 .../src/fi/semantum/sysdyn/solver/Model.java  |  96 +++++++++++-----
 .../semantum/sysdyn/solver/Subtraction.java   |  11 +-
 .../semantum/sysdyn/solver/VariableBase.java  |  36 +++---
 13 files changed, 349 insertions(+), 229 deletions(-)

diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Addition.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Addition.java
index 8c09ab6f..6c531d41 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Addition.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Addition.java
@@ -12,6 +12,8 @@ package fi.semantum.sysdyn.solver;
 
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class Addition implements IExpression {
 	
     public IExpression exp1;
@@ -38,7 +40,14 @@ public class Addition implements IExpression {
 		if(o1 instanceof Array && o2 instanceof Array) {
 			Array la = (Array)o1;
 			Array ra = (Array)o2;
-			return la.add(ra);
+			return la.copy2(ra, new Modifier2() {
+				
+				@Override
+				public Object modify(Object o1, Object o2) {
+					if(o1 instanceof Double && o2 instanceof Double) return ((Double)o1)+((Double)o2);
+					throw new IllegalStateException("Tried to add a non-numerical array");
+				}
+			});
 		}
 		throw new IllegalStateException();
 	}
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Array.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Array.java
index eaa4cca1..8c34ffc4 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Array.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Array.java
@@ -301,75 +301,7 @@ public class Array implements IExpression {
 		throw new IllegalStateException();
 		
 	}
-	
-	public Array add(Array other) {
-		Array result = new Array();
-		Collection<Object> lae = elements();
-		Collection<Object> rae = other.elements();
-		if(lae.size() != rae.size()) throw new IllegalStateException();
-		Iterator<Object> li = lae.iterator();
-		Iterator<Object> ri = rae.iterator();
-		for(int i=0;i<lae.size();i++) {
-			Object l = li.next();
-			Object r = ri.next();
-			if(l instanceof Double && r instanceof Double) {
-				result.addElement(((Double)l)+((Double)r));
-			} else if (l instanceof Array && r instanceof Array) {
-				Array arr = (Array)l;
-				Array otherArr = (Array)r;
-				result.addElement(arr.add(otherArr));
-			} else {
-				throw new IllegalStateException();
-			}
-		}
-		return result;
-	}
-
-	public Array sub(Array other) {
-		Array result = new Array();
-		Collection<Object> lae = elements();
-		Collection<Object> rae = other.elements();
-		if(lae.size() != rae.size()) throw new IllegalStateException();
-		Iterator<Object> li = lae.iterator();
-		Iterator<Object> ri = rae.iterator();
-		for(int i=0;i<lae.size();i++) {
-			Object l = li.next();
-			Object r = ri.next();
-			if(l instanceof Double && r instanceof Double) {
-				result.addElement(((Double)l)-((Double)r));
-			} else if (l instanceof Array && r instanceof Array) {
-				Array arr = (Array)l;
-				Array otherArr = (Array)r;
-				result.addElement(arr.sub(otherArr));
-			} else {
-				throw new IllegalStateException();
-			}
-		}
-		return result;
-	}
 
-	public Array mul(Array other) {
-		Array result = new Array();
-		Collection<Object> lae = elements();
-		Collection<Object> rae = other.elements();
-		if(lae.size() != rae.size()) throw new IllegalStateException();
-		Iterator<Object> li = lae.iterator();
-		Iterator<Object> ri = rae.iterator();
-		for(int i=0;i<lae.size();i++) {
-			Object l = li.next();
-			Object r = ri.next();
-			if(l instanceof Double && r instanceof Double) {
-				result.addElement(((Double)l)*((Double)r));
-			} else if (l instanceof Array && r instanceof Array) {
-				Array arr = (Array)l;
-				Array otherArr = (Array)r;
-				result.addElement(arr.mul(otherArr));
-			} else {
-				throw new IllegalStateException();
-			}
-		}
-		return result;
-	}
 	/*
 	 * Both arrays are vectors 
 	 */
@@ -445,6 +377,10 @@ public class Array implements IExpression {
 		Object modify(Object o);
 	}
 	
+	interface Modifier2 {
+		Object modify(Object o1, Object o2);
+	}
+
 	public Array copy(Modifier modifier) {
 		Array result = new Array();
 		for(Object element : elements) {
@@ -458,6 +394,33 @@ public class Array implements IExpression {
 		return result;
 	}
 	
+	public Array copy2(Array other, Modifier2 modifier) {
+		Array result = new Array();
+		Collection<Object> es = elements();
+		Collection<Object> oes = other.elements();
+		if(es.size() != oes.size()) throw new IllegalStateException("Array dimensions do not match");
+		Iterator<Object> e = es.iterator();
+		Iterator<Object> oe = oes.iterator();
+		for(int i=0;i<es.size();i++) {
+			Object element = e.next();
+			Object otherElement = oe.next();
+			if(element instanceof Array) {
+				if(otherElement instanceof Array) {
+					result.addElement(((Array)element).copy2((Array)otherElement, modifier));
+				} else {
+					throw new IllegalStateException("Array dimensions do not match");
+				}
+			} else {
+				if(otherElement instanceof Array) {
+					throw new IllegalStateException("Array dimensions do not match");
+				} else {
+					result.addElement(modifier.modify(element, otherElement));
+				}
+			}				
+		}
+		return result;
+	}
+
 	public boolean isVector() {
 		return isVector;
 	}
@@ -474,13 +437,13 @@ public class Array implements IExpression {
 					if(element instanceof Array) throw new IllegalStateException();
 					if(element instanceof IExpression) {
 						IExpression exp = (IExpression)element;
-						return exp.evaluate(environment);
+						ret.addElement(exp.evaluate(environment));
 					} else {
 						ret.addElement(element);
 					}
 				} else {
 					if(element instanceof Array) {
-						return ret.addElement(((Array)element).subscript(environment, subscripts, position+1));
+						ret.addElement(((Array)element).subscript(environment, subscripts, position+1));
 					} else {
 						throw new IllegalStateException();
 					}
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 6e3772a8..b5194f7f 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
@@ -12,6 +12,8 @@ package fi.semantum.sysdyn.solver;
 
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class Derivate implements IExpression {
 
 	private Variable variable;
@@ -26,11 +28,9 @@ public class Derivate implements IExpression {
 	
 	@Override
 	public Object evaluate(IEnvironment _environment) {
-		Environment environment = (Environment)_environment;
-//		Double old = (Double)environment.getValue(variable.name + variable.subscriptKey());
+		final Environment environment = (Environment)_environment;
 		Object old = variable.evaluate(environment);
 		
-//		Double old = (Double)environment.getValue(variable.base.index(_environment, subscripts));
 		// FIXME: should not be fixed like this
 		if(old == null) old = 0.0;
 		Object eval = e.evaluate(environment);
@@ -39,13 +39,18 @@ public class Derivate implements IExpression {
 		} else if (eval instanceof Array) {
 			Array arr = (Array)eval;
 			Array oldArray = (Array)old;
-			Array result = new Array();
-			for(int i=0;i<arr.dimension();i++) {
-				Double d = (Double)arr.element(i);
-				Double o = (Double)oldArray.element(i);
-				result.addElement(o+environment.step*d);
-			}
-			return result;
+			
+			return oldArray.copy2(arr, new Modifier2() {
+
+				@Override
+				public Object modify(Object o1, Object o2) {
+					Double oldValue = (Double)o1;
+					Double der = (Double)o2;
+					return oldValue + environment.step*der;
+				}
+				
+			});
+			
 		} else {
 			throw new UnsupportedOperationException();
 		}
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Division.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Division.java
index d8d357fe..42ce0597 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Division.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Division.java
@@ -12,6 +12,8 @@ package fi.semantum.sysdyn.solver;
 
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier;
+
 public class Division implements IExpression {
 	
     public IExpression exp1;
@@ -27,16 +29,17 @@ public class Division implements IExpression {
     	return exp1 + " / " + exp2;
     }
     
-    private Array arrayDiv(Array a, Double d) {
-    	Array result = new Array();
-    	for(Object o : a.elements()) {
-    		if(o instanceof Double) {
-    			result.addElement((Double)o/d);
-    		} else {
-    			throw new IllegalStateException();
-    		}
-    	}
-    	return result;
+    private Array arrayDiv(Array a, final Double d) {
+    	return a.copy(new Modifier() {
+			@Override
+			public Object modify(Object o) {
+	    		if(o instanceof Double) {
+	    			return ((Double)o)/d;
+	    		} else {
+	    			throw new IllegalStateException();
+	    		}
+			}
+		});
     }
     
 	@Override
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseDivision.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseDivision.java
index 51c91e92..ffb93df7 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseDivision.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseDivision.java
@@ -10,10 +10,11 @@
  *******************************************************************************/
 package fi.semantum.sysdyn.solver;
 
-import java.util.Collection;
-import java.util.Iterator;
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier;
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class ElementwiseDivision implements IExpression {
 	
     public IExpression exp1;
@@ -36,33 +37,41 @@ public class ElementwiseDivision implements IExpression {
 		if(left instanceof Array && right instanceof Array) {
 			Array la = (Array)left;
 			Array ra = (Array)right;
-			Collection<Object> lae = la.elements();
-			Collection<Object> rae = ra.elements();
-			if(lae.size() != rae.size()) throw new UnsupportedOperationException();
-			Iterator<Object> li = lae.iterator();
-			Iterator<Object> ri = rae.iterator();
-			Array result = new Array();
-			for(int i=0;i<lae.size();i++) {
-				double ld = (Double)li.next();
-				double rd = (Double)ri.next();
-				result.addElement(ld/rd);
-			}
-			return result;
+			return la.copy2(ra, new Modifier2() {
+				
+				@Override
+				public Object modify(Object o1, Object o2) {
+					if(o1 instanceof Double && o2 instanceof Double) return ((Double)o1)/((Double)o2);
+					throw new IllegalStateException("Tried to divide a non-numerical array");
+				}
+				
+			});
 		} else if(left instanceof Array && right instanceof Double) {
 			Array la = (Array)left;
-			double rd = (Double)right;
-			Collection<Object> lae = la.elements();
-			Iterator<Object> li = lae.iterator();
-			Array result = new Array();
-			for(int i=0;i<lae.size();i++) {
-				double ld = (Double)li.next();
-				result.addElement(ld/rd);
-			}
-			return result;
+			final double rd = (Double)right;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return ((Double)o)/rd;
+					else throw new IllegalStateException("Tried to divide a non-numerical array");
+				}
+				
+			});
+		} else if(left instanceof Double && right instanceof Array) {
+			Array la = (Array)right;
+			final double rd = (Double)left;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return rd / ((Double)o);
+					else throw new IllegalStateException("Tried to divide a non-numerical array");
+				}
+				
+			});
 		} else if(left instanceof Double && right instanceof Double) {
-			double ld = (Double)left;
-			double rd = (Double)right;
-			return ld*rd;
+			return ((Double)left)/((Double)right);
 		} else {
 			throw new UnsupportedOperationException();
 		}
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwisePower.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwisePower.java
index 6fac7280..15ac7bc5 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwisePower.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwisePower.java
@@ -10,10 +10,11 @@
  *******************************************************************************/
 package fi.semantum.sysdyn.solver;
 
-import java.util.Collection;
-import java.util.Iterator;
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier;
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class ElementwisePower implements IExpression {
 	
     public IExpression exp1;
@@ -36,19 +37,41 @@ public class ElementwisePower implements IExpression {
 		if(left instanceof Array && right instanceof Array) {
 			Array la = (Array)left;
 			Array ra = (Array)right;
-			Collection<Object> lae = la.elements();
-			Collection<Object> rae = ra.elements();
-			if(lae.size() != rae.size()) throw new UnsupportedOperationException();
-			Iterator<Object> li = lae.iterator();
-			Iterator<Object> ri = rae.iterator();
-			Array result = new Array();
-			for(int i=0;i<lae.size();i++) {
-				double ld = (Double)li.next();
-				double rd = (Double)ri.next();
-				result.addElement(Math.pow(ld,rd));
-			}
-			return result;
-		} else throw new UnsupportedOperationException();
+			return la.copy2(ra, new Modifier2() {
+				
+				@Override
+				public Object modify(Object o1, Object o2) {
+					if(o1 instanceof Double && o2 instanceof Double) return Math.pow((Double)o1,(Double)o2);
+					throw new IllegalStateException("Tried to pow a non-numerical array");
+				}
+			});
+		} else if (left instanceof Array && right instanceof Double) {
+			Array la = (Array)left;
+			final double rd = (Double)right;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return Math.pow((Double)o,rd);
+					else throw new IllegalStateException("Tried to pow a non-numerical array");
+				}
+				
+			});
+		} else if (left instanceof Double && right instanceof Array) {
+			Array la = (Array)right;
+			final double rd = (Double)left;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return Math.pow(rd,(Double)o);
+					else throw new IllegalStateException("Tried to pow a non-numerical array");
+				}
+				
+			});
+		} else {
+			throw new UnsupportedOperationException();
+		}
 	}
 	
 	@Override
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseProduct.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseProduct.java
index fa670ac8..b15f6781 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseProduct.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/ElementwiseProduct.java
@@ -10,11 +10,11 @@
  *******************************************************************************/
 package fi.semantum.sysdyn.solver;
 
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier;
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class ElementwiseProduct implements IExpression {
 	
     public IExpression exp1;
@@ -37,37 +37,38 @@ public class ElementwiseProduct implements IExpression {
 		if(left instanceof Array && right instanceof Array) {
 			Array la = (Array)left;
 			Array ra = (Array)right;
-			List<Object> lae = la.elements();
-			List<Object> rae = ra.elements();
-			if(lae.size() != rae.size()) throw new UnsupportedOperationException();
-			Array result = new Array(lae.size());
-			int index = 0;
-			for(Object o : lae) {
-				Double ld = (Double)o;
-				Double rd = (Double)rae.get(index++);
-				result.addElement(ld*rd);
-			}
-			return result;
+			return la.copy2(ra, new Modifier2() {
+				
+				@Override
+				public Object modify(Object o1, Object o2) {
+					if(o1 instanceof Double && o2 instanceof Double) return ((Double)o1)*((Double)o2);
+					throw new IllegalStateException("Tried to multiply a non-numerical array");
+				}
+			});
 		} else if (left instanceof Array && right instanceof Double) {
 			Array la = (Array)left;
-			Double rd = (Double)right;
-			List<Object> lae = la.elements();
-			Array result = new Array(lae.size());
-			for(Object o : lae) {
-				Double ld = (Double)o;
-				result.addElement(ld*rd);
-			}
-			return result;
+			final double rd = (Double)right;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return ((Double)o)*rd;
+					else throw new IllegalStateException("Tried to multiply a non-numerical array");
+				}
+				
+			});
 		} else if (left instanceof Double && right instanceof Array) {
-			Array ra = (Array)right;
-			Double ld = (Double)left;
-			List<Object> rae = ra.elements();
-			Array result = new Array(rae.size());
-			for(Object o : rae) {
-				Double rd = (Double)o;
-				result.addElement(ld*rd);
-			}
-			return result;
+			Array la = (Array)right;
+			final double rd = (Double)left;
+			return la.copy(new Modifier() {
+
+				@Override
+				public Object modify(Object o) {
+					if(o instanceof Double) return ((Double)o)*rd;
+					else throw new IllegalStateException("Tried to multiply a non-numerical array");
+				}
+				
+			});
 		} else {
 			throw new UnsupportedOperationException();
 		}
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 84d8afed..b4dc80e0 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
@@ -16,6 +16,7 @@ import gnu.trove.list.array.TIntArrayList;
 import gnu.trove.map.hash.TObjectIntHashMap;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -29,7 +30,7 @@ interface Fn {
 	public Object evaluateInput(IEnvironment environment, int argPosition);
 	public void setLocals(IEnvironment environment);
 	public int offset();
-	public Variable[] parameters();
+	public Variable[] parameters(int args);
 }
 
 abstract class Fn1 implements Fn {
@@ -37,17 +38,25 @@ abstract class Fn1 implements Fn {
 	Variable[] parameters;
 	
 	public Fn1(int pCount) {
-		parameters = new Variable[pCount];
-		for(int i=0;i<pCount;i++)
-			parameters[i] = new Variable(new VariableBase("", i));
+		if(pCount > 0) {
+			parameters = new Variable[pCount];
+			for(int i=0;i<pCount;i++)
+				parameters[i] = new Variable(new VariableBase("", i));
+		}
 	}
 	
 	public int offset() {
 		return 0;
 	}
 	
-	public Variable[] parameters() {
-		return parameters;
+	public Variable[] parameters(int argc) {
+		if(parameters != null) return parameters;
+		else {
+			Variable[] ret = new Variable[argc];
+			for(int i=0;i<argc;i++)
+				ret[i] = new Variable(new VariableBase("", i));
+			return ret;
+		}
 	}
 	
 	@Override
@@ -349,38 +358,75 @@ final public class Environment implements IEnvironment, ISystem {
 		});
 		model.functions.put("sum", new Fn1(1) {
 
+			public double sum(Array a) {
+				double res = 0;
+				for(Object element : a.elements()) {
+					if(element instanceof Array) {
+						res += sum((Array)element);
+					} else if(element instanceof Double) {
+						res += (Double)element;
+					} else {
+						throw new IllegalStateException("Tried to sum a non-numerical array");
+					}
+				}
+				return res;
+			}
+			
 			@Override
 			public Object evaluate(IEnvironment environment, int argc) {
 				Object value = environment.getValue(0);
+				if(value instanceof Double) return (Double)value;
 				Array arr = (Array)value;
-				double res = 0;
-				for(Object o : arr.elements())
-					res += (Double)o;
-				return res;
+				return sum(arr);
 			}
 			
 		});
-		model.functions.put("ones", new Fn1(1) {
+		model.functions.put("ones", new Fn1(-1) {
 
+			private Array make(int[] dims, int pos) {
+				Array result = new Array();
+				int d = dims[pos];
+				if(pos == dims.length - 1) {
+					for(int i=0;i<d;i++) result.addElement(1.0);
+				} else {
+					for(int i=0;i<d;i++) result.addElement(make(dims, pos+1));
+				}
+				return result;
+			}
+			
 			@Override
 			public Object evaluate(IEnvironment environment, int argc) {
-				Object value = environment.getValue(0);
-				Double size = (Double)value;
-				Array res = new Array();
-				for(int i=0;i<size.intValue();i++) res.addElement(1.0);
-				return res;
+				int[] dims = new int[argc];
+				for(int i=0;i<argc;i++) {
+					Double d = (Double)environment.getValue(0);
+					dims[i] = d.intValue();
+				}
+				return make(dims, 0);
 			}
 			
 		});
-		model.functions.put("zeros", new Fn1(1) {
+		model.functions.put("zeros", new Fn1(-1) {
 
+			private Array make(int[] dims, int pos) {
+				Array result = new Array();
+				int d = dims[pos];
+				if(pos == dims.length - 1) {
+					for(int i=0;i<d;i++) result.addElement(0.0);
+				} else {
+					for(int i=0;i<d;i++) result.addElement(make(dims, pos+1));
+				}
+				return result;
+			}
+			
 			@Override
 			public Object evaluate(IEnvironment environment, int argc) {
-				Object value = environment.getValue(0);
-				Double size = (Double)value;
-				Array res = new Array();
-				for(int i=0;i<size.intValue();i++) res.addElement(0.0);
-				return res;
+				int[] dims = new int[argc];
+				for(int i=0;i<argc;i++) {
+					Double d = (Double)environment.getValue(i);
+					dims[i] = d.intValue();
+				}
+				System.err.println("zeros " + Arrays.toString(dims));
+				return make(dims, 0);
 			}
 			
 		});
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Function.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Function.java
index 3c32e6e9..200cf365 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Function.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Function.java
@@ -106,7 +106,7 @@ final public class Function implements Fn, IFrame {
 	}
 	
 	@Override
-	public Variable[] parameters() {
+	public Variable[] parameters(int argc) {
 		return parameters;
 	}
 	
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/GreaterThan.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/GreaterThan.java
index e91f0ffc..5735e4b6 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/GreaterThan.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/GreaterThan.java
@@ -29,7 +29,9 @@ public class GreaterThan implements IExpression {
     
 	@Override
 	public Object evaluate(IEnvironment environment) {
-		return ((Double)exp1.evaluate(environment)) > ((Double)exp2.evaluate(environment));
+		Object left = exp1.evaluate(environment);
+		Object right = exp2.evaluate(environment);
+		return ((Double)left) > ((Double)right);
 	}
 
 	@Override
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Model.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Model.java
index a5fde8b0..537d238f 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Model.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Model.java
@@ -13,6 +13,7 @@ package fi.semantum.sysdyn.solver;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
@@ -98,7 +99,7 @@ class Model implements IFrame {
 				argh.add(args.args[i].modification.evaluate(environment));
 			}
 			
-			Variable[] parameters = fn.parameters();
+			Variable[] parameters = fn.parameters(argh.size());
 			
 			for(int i=0;i<args.args.length+1;i++) {
 				Variable var = parameters[i];
@@ -121,10 +122,12 @@ class Model implements IFrame {
 				argh.add(arg);
 			}
 			
-			Variable[] parameters = fn.parameters();
+			Variable[] parameters = fn.parameters(args.args.length);
 			Object[] ps = new Object[parameters.length];
+			boolean vector[] = new boolean[parameters.length];
 			
 			int vectorDimension = 0;
+			ArrayList<Array> arrs = new ArrayList<Array>();
 			for(int i=0;i<parameters.length;i++) {
 				Variable var = parameters[i];
 				if(i < argh.size()) {
@@ -132,33 +135,20 @@ class Model implements IFrame {
 				} else {
 					ps[i] = fn.evaluateInput(environment, i);
 				}
-				if(var.base.dimensions == null && ps[i] instanceof Array)
-					vectorDimension = ((Array)ps[i]).dimension();
+				if(var.base.dimensions == null && ps[i] instanceof Array) {
+					int dim = ((Array)ps[i]).dimension();
+					if(vectorDimension > 0 && dim != vectorDimension) throw new IllegalStateException("Array dimensions do not agree");
+					vectorDimension = dim;
+					vector[i] = true;
+					arrs.add((Array)ps[i]);
+				} else {
+					vector[i] = false;
+				}
 			}
 			
 			if(vectorDimension > 0) {
-
-				Array result = new Array();
-				
-				for(int i=0;i<vectorDimension;i++) {
-
-					for(int j=0;j<parameters.length;j++) {
-						Object o = ps[j];
-						if(o instanceof Array) {
-							Object sub = ((Array)o).element(i);
-							parameters[j].assignPlain(frame, sub);
-						} else {
-							parameters[j].assignPlain(frame, o);
-						}
-					}
-					
-					fn.setLocals(frame);
-					Object ret = fn.evaluate(frame, args.args.length);
-					result.addElement(ret);
-					
-				}
 				
-				return result;
+				return arrayEvaluate(frame, fn, parameters, ps, vector, arrs);
 				
 			} else {
 			
@@ -167,7 +157,8 @@ class Model implements IFrame {
 				}
 				
 				fn.setLocals(frame);
-				return fn.evaluate(frame, args.args.length);
+				Object value = fn.evaluate(frame, args.args.length); 
+				return value;
 				
 			}
 			
@@ -175,6 +166,59 @@ class Model implements IFrame {
 			
 	}
 	
+	private Array arrayEvaluate(Frame frame, Fn fn, Variable[] parameters, Object[] ps, boolean[] vector, List<Array> arrs) {
+		
+		Array result = new Array();
+
+		Array first = arrs.get(0);
+		
+		int d = first.elements().size();
+		if(d == 0) return result;
+
+		Object firstElement = first.element(0);
+		boolean subArray = firstElement instanceof Array;
+		
+		for(int i=0;i<d;i++) {
+
+			int vectorIndex = 0;
+
+			if(subArray) {
+
+				ArrayList<Array> subArrs = new ArrayList<Array>();
+				for(int j=0;j<parameters.length;j++) {
+					if(vector[j]) {
+						Array a = arrs.get(vectorIndex++);
+						Array sub = (Array)a.element(i);
+						subArrs.add(sub);
+					}
+				}
+				
+				result.addElement(arrayEvaluate(frame, fn, parameters, ps, vector, subArrs));
+
+			} else {
+
+				for(int j=0;j<parameters.length;j++) {
+					if(vector[j]) {
+						Array a = arrs.get(vectorIndex++);
+						Object sub = a.element(i);
+						parameters[j].assignPlain(frame, sub);
+					} else {
+						parameters[j].assignPlain(frame, ps[j]);
+					}
+				}
+
+				fn.setLocals(frame);
+				Object ret = fn.evaluate(frame, parameters.length);
+				result.addElement(ret);
+				
+			}
+			
+		}			
+		
+		return result;
+
+	}
+	
 	private VariableBase resolveCopy(Map<String,VariableBase> work, VariableBase target) {
 		VariableBase deep = work.get(target.name);
 		if(deep == null) return target;
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Subtraction.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Subtraction.java
index 4ef86db8..e908d74d 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Subtraction.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/Subtraction.java
@@ -12,6 +12,8 @@ package fi.semantum.sysdyn.solver;
 
 import java.util.Map;
 
+import fi.semantum.sysdyn.solver.Array.Modifier2;
+
 public class Subtraction implements IExpression {
 	
     public IExpression exp1;
@@ -39,7 +41,14 @@ public class Subtraction implements IExpression {
 		if(o1 instanceof Array && o2 instanceof Array) {
 			Array la = (Array)o1;
 			Array ra = (Array)o2;
-			return la.sub(ra);
+			return la.copy2(ra, new Modifier2() {
+				
+				@Override
+				public Object modify(Object o1, Object o2) {
+					if(o1 instanceof Double && o2 instanceof Double) return ((Double)o1)-((Double)o2);
+					throw new IllegalStateException("Tried to subtract a non-numerical array");
+				}
+			});
 		}
 		throw new IllegalStateException();
 	}
diff --git a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/VariableBase.java b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/VariableBase.java
index e0a57a6c..40c75d2d 100644
--- a/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/VariableBase.java
+++ b/fi.semantum.sysdyn.solver/src/fi/semantum/sysdyn/solver/VariableBase.java
@@ -219,24 +219,30 @@ public class VariableBase {
 			else return array;
 			
 		} else {
-			
+
 			if(dimension() > 1) {
+
+				Array array = new Array();
+				intoArray(environment, index, 0, array);
 				if(subscripts != null) {
-					
-					Array[] sub = SolverUtils.parseSubscripts(environment, subscripts);
-					if(SolverUtils.isSlice(sub)) {
-						Array arr = new Array();
-						intoArray(environment, index, 0, arr);
-						return arr.slice(sub);
-					} else { 
-						return environment.getValue(index(environment, subscripts));
-					}
-					
-				} else {
-					Array array = new Array();
-					intoArray(environment, index, 0, array);
-					return array;
+					return array.subscript(environment, subscripts);
 				}
+				else return array;
+
+//				if(subscripts != null) {
+//					
+//					Array[] sub = SolverUtils.parseSubscripts(environment, subscripts);
+//					if(SolverUtils.isSlice(sub)) {
+//						Array arr = new Array();
+//						intoArray(environment, index, 0, arr);
+//						return arr.slice(sub);
+//					} else { 
+//						return environment.getValue(index(environment, subscripts));
+//					}
+//					
+//				} else {
+//					return array;
+//				}
 			}
 			
 			Object result = environment.getNamedValue(name);
-- 
2.47.1