Multiply


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.util.*;
12  import org.nfunk.jep.*;
13  import org.nfunk.jep.type.*;
14  
15  public class Multiply extends PostfixMathCommand
16  {
17      
18      public Multiply() {
19          numberOfParameters = -1;
20      }
21      
22      public void run(Stack stack) throws ParseException 
23      {
24          checkStack(stack); // check the stack
25  
26          Object   product = stack.pop();
27          Object   param;
28          int i = 1;
29          
30          // repeat summation for each one of the current parameters
31          while (i < curNumberOfParameters) {
32              // get the parameter from the stack
33              param = stack.pop();
34              
35              // multiply it with the product, order is important
36              // if matricies are used
37              product = mul(param,product);
38                  
39              i++;
40          }
41                  
42          stack.push(product);
43  
44          return;
45      }
46      
47      public Object   mul(Object   param1, Object   param2)
48          throws ParseException
49      {
50          if (param1 instanceof Complex)
51          {
52              if (param2 instanceof Complex)
53                  return mul((Complex)param1, (Complex)param2);
54              else if (param2 instanceof Number  )
55                  return mul((Complex)param1, (Number  )param2);
56              else if (param2 instanceof Vector)
57                  return mul((Vector)param2, (Complex)param1);
58          }
59          else if (param1 instanceof Number  )
60          {
61              if (param2 instanceof Complex)
62                  return mul((Complex)param2, (Number  )param1);
63              else if (param2 instanceof Number  )
64                  return mul((Number  )param1, (Number  )param2);
65              else if (param2 instanceof Vector)
66                  return mul((Vector)param2, (Number  )param1);
67          }
68          else if (param1 instanceof Vector)
69          {
70              if (param2 instanceof Complex)
71                  return mul((Vector)param1, (Complex)param2);
72              else if (param2 instanceof Number  )
73                  return mul((Vector)param1, (Number  )param2);
74          }
75          
76          throw new ParseException("Invalid parameter type");
77      }
78      
79      public Double   mul(Number   d1, Number   d2)
80      {
81          return new Double  (d1.doubleValue()*d2.doubleValue());   
82      }   
83      
84      public Complex mul(Complex c1, Complex c2)
85      {
86          return c1.mul(c2);
87      }
88      
89      public Complex mul(Complex c, Number   d)
90      {
91          return c.mul(d.doubleValue());  
92      }
93      
94      public Vector mul(Vector v, Number   d)
95      {
96          Vector result = new Vector();
97  
98          for (int i=0; i<v.size(); i++)
99              result.addElement(mul((Number  )v.elementAt(i), d));
100         
101         return result;
102     }
103     
104     public Vector mul(Vector v, Complex c)
105     {
106         Vector result = new Vector();
107 
108         for (int i=0; i<v.size(); i++)
109             result.addElement(mul(c, (Number  )v.elementAt(i)));
110         
111         return result;
112     }   
113 }
114
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