first commit

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

@@ -0,0 +1,26 @@
+package org.nfunk.jep.function;
+
+import java.util.Stack;
+import org.nfunk.jep.ParseException;
+import org.nfunk.jep.type.Complex;
+
+public class NaturalLogarithm extends PostfixMathCommand {
+  public void run(Stack paramStack) throws ParseException {
+    checkStack(paramStack);
+    Object object = paramStack.pop();
+    paramStack.push(ln(object));
+  }
+  
+  public Object ln(Object paramObject) throws ParseException {
+    if (paramObject instanceof Complex)
+      return ((Complex)paramObject).log(); 
+    if (paramObject instanceof Number) {
+      double d = ((Number)paramObject).doubleValue();
+      if (d > 0.0D)
+        return new Double(Math.log(d)); 
+      Complex complex = new Complex(d);
+      return complex.log();
+    } 
+    throw new ParseException("Invalid parameter type");
+  }
+}