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Index › Processing Development › Libraries,  Tool Development › Get started creating libraries
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Get started creating libraries (Read 4284 times)
frankb
Re: Get started creating libraries
Reply #15 - Nov 27th, 2006, 12:01am  
Please be patient with these dumb questions I’m a student and fairly new to all this. This is what I have now but I think I am doing something wrong in processing.

This is the code in processing

Code:


import pFem.*;

  int a= FemCalc.Add(2,3);  
    print (a);

  int b[][] = FemCalc.myFunc(1,1);
    print (b[1][1]);

This is the java code.
Code:

package pFem;

public class FemCalc {

public static int arr[][];

    public static int Add(int a, int b)
    {
    return(a+b);
    } 
    
    public static int[][] myFunc(int a, int b)
    {
    arr[1][1] = a+b;
return arr;
    }
}
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JohnG
Re: Get started creating libraries
Reply #16 - Nov 27th, 2006, 12:20am  
Code:
package pFem;

public class FemCalc {

public static int arr[][];

    public static int Add(int a, int b)
    {
    return(a+b);
    } 
    
    public static int[][] myFunc(int a, int b)
    {
/* -->>    arr[1][1] = a+b;  arr hasn't been initialised, you're accessing [1][1] when the array is null. Also, you probably want 0, not 1, since arrays are 0-index */
	if(arr==null)
	{
	  arr=new int[3][3];
	}
	arr[0][0]=a+b;
return arr;
    }
}
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frankb
Re: Get started creating libraries
Reply #17 - Nov 27th, 2006, 1:27am  
awsome, ok I feel up to speed for now thank you all for your help.
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frankb
Re: Get started creating libraries
Reply #18 - Nov 27th, 2006, 1:35am  
How would I put an array back into the function from processing. for example.

this is the java

Code:


package pFem;
 
public class FemCalc {


public static int local[][];
 
    public static int Add(int a, int b)
    {
    return(a+b);
    }  
     
    
    public static int[][] localMatrix(int a[], int b)
    {
    
/* -->>    arr[1][1] = a+b;  arr hasn't been initialised, 
 * you're accessing [1][1] when the array is null. Also, 
 * you probably want 0, not 1, since arrays are 0-index */
    
 if(local==null)
 {
   local=new int[3][3];
 }

 
 local[0][0]=a[0]+b;
 local[0][1]=a[1]+b+1;
 

 
return local;
    }
}


This is what I am doing in processing.

Code:


import pFem.*;
   
int arr[] = {1,2};
  int b[][] = FemCalc.myFunc(arr[],1);
     print (b[0][0]);
     print (b[0][1]);
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frankb
Re: Get started creating libraries
Reply #19 - Nov 27th, 2006, 4:35pm  
If it helps this is the error from processing

C:/DOCUME~1/Frank/LOCALS~1/Temp/build32044.tmp/Temporary_8810_1604.java:7:33:7:3
3: Syntax Error: Expression expected after this token

it works fine in eclipse

I would realy appreciate it if someone could help me with this.
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JohnG
Re: Get started creating libraries
Reply #20 - Nov 27th, 2006, 5:18pm  
Code:
import pFem.*;
   
  int arr[] = new int[]{1,2};
  int b[][] = FemCalc.myFunc(arr[],1);
  print (b[0][0]);
  print (b[0][1]);

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frankb
Re: Get started creating libraries
Reply #21 - Nov 27th, 2006, 8:16pm  
that seems to be giving me the same error.
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JohnG
Re: Get started creating libraries
Reply #22 - Nov 27th, 2006, 8:54pm  
Sorry yes, didn't see that error as well:

Code:
import pFem.*;
   
  int arr[] = new int[]{1,2}; /* might be better writing this with "int[] arr" so you remember that the variable is called "arr" the [] just says it's an array, it's not part of the name.*/

  int b[][] = FemCalc.myFunc(arr,1); // removed the [] processing knows it's an array, you only put the [] if you want to access part of it.

  print (b[0][0]);
  print (b[0][1]);
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