first commit

hrmsEjb/org/nfunk/jep/function/Cross.java

@@ -0,0 +1,39 @@
+package org.nfunk.jep.function;
+
+import java.util.Stack;
+import java.util.Vector;
+import org.nfunk.jep.ParseException;
+
+public class Cross extends PostfixMathCommand {
+  static Subtract sub = new Subtract();
+  
+  static Multiply mul = new Multiply();
+  
+  public void run(Stack paramStack) throws ParseException {
+    checkStack(paramStack);
+    Object object1 = paramStack.pop();
+    Object object2 = paramStack.pop();
+    paramStack.push(cross(object2, object1));
+  }
+  
+  public Object cross(Object paramObject1, Object paramObject2) throws ParseException {
+    if (paramObject1 instanceof Vector && paramObject2 instanceof Vector)
+      return cross((Vector)paramObject1, (Vector)paramObject2); 
+    throw new ParseException("Cross: Invalid parameter type, both arguments must be vectors");
+  }
+  
+  public Object cross(Vector paramVector1, Vector paramVector2) throws ParseException {
+    int i = paramVector1.size();
+    if ((i != 2 && i != 3) || i != paramVector2.size())
+      throw new ParseException("Cross: both sides must be of length 3"); 
+    if (i == 3) {
+      Vector vector = new Vector(3);
+      vector.setSize(3);
+      vector.setElementAt(sub.sub(mul.mul(paramVector1.elementAt(1), paramVector2.elementAt(2)), mul.mul(paramVector1.elementAt(2), paramVector2.elementAt(1))), 0);
+      vector.setElementAt(sub.sub(mul.mul(paramVector1.elementAt(2), paramVector2.elementAt(0)), mul.mul(paramVector1.elementAt(0), paramVector2.elementAt(2))), 1);
+      vector.setElementAt(sub.sub(mul.mul(paramVector1.elementAt(0), paramVector2.elementAt(1)), mul.mul(paramVector1.elementAt(1), paramVector2.elementAt(0))), 2);
+      return vector;
+    } 
+    return sub.sub(mul.mul(paramVector1.elementAt(0), paramVector2.elementAt(1)), mul.mul(paramVector1.elementAt(1), paramVector2.elementAt(0)));
+  }
+}