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Java > Open Source Codes > org > nfunk > jep > function > Abs


1 /*****************************************************************************
2
3 JEP - Java Math Expression Parser 2.3.0
4       October 3 2004
5       (c) Copyright 2004, Nathan Funk and Richard Morris
6       See LICENSE.txt for license information.
7
8 *****************************************************************************/
9 package org.nfunk.jep.function;
10
11 import java.lang.Math JavaDoc;
12 import java.util.*;
13 import org.nfunk.jep.*;
14 import org.nfunk.jep.type.*;
15
16 public class Abs extends PostfixMathCommand
17 {
18     public Abs()
19     {
20         numberOfParameters = 1;
21     }
22     
23     public void run(Stack inStack)
24         throws ParseException
25     {
26         checkStack(inStack);// check the stack
27 Object JavaDoc param = inStack.pop();
28         inStack.push(abs(param));//push the result on the inStack
29 return;
30     }
31
32
33     public Object JavaDoc abs(Object JavaDoc param)
34         throws ParseException
35     {
36         if (param instanceof Complex)
37         {
38             return new Double JavaDoc(((Complex)param).abs());
39         }
40         else if (param instanceof Number JavaDoc)
41         {
42             return new Double JavaDoc(Math.abs(((Number JavaDoc)param).doubleValue()));
43         }
44
45         throw new ParseException("Invalid parameter type");
46     }
47
48 }
49
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