Passing 2d arrays to a function

This is a discussion on Passing 2d arrays to a function within the C++ Programming forums, part of the General Programming Boards category; OK, I think I've lost all my C++ knowledge here. i can't properly pass a 2D array of floats to ...

  1. #1
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    Passing 2d arrays to a function

    OK, I think I've lost all my C++ knowledge here. i can't properly pass a 2D array of floats to a function.

    I have a dynamically allocated 2d array of float and I have a function that should fill it. The size is known before the call for the function.
    I have this:
    the function deffinition
    Code:
    void GetData(FILE *ptr, FILE *out, unsigned int Mask[], float &mtxVicVals, int n , int s)
    {
    ........
                                 if(Mask[j] == 1)
    				{
    					mtxVicVals[i][p] = Values[j];
    					p++;
    				}
    .............
    }
    the function call
    Code:
    GetData(inp, out, Mask, mtxVicVals,  vars.NumParam, vars.NumScan);
    I know I'm thinking of it as a 1D array. Will I use two & in th declaration?
    Last edited by earth_angel; 07-18-2005 at 08:58 AM.
    Everything is relative...

  2. #2
    C/C++Newbie Antigloss's Avatar
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    how about this?
    float **mtxVicVals

  3. #3
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    it compiles, but I get a run-time error that memory could not be written.
    but would passing by reference be faster?
    Everything is relative...

  4. #4
    C/C++Newbie Antigloss's Avatar
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    let me see...

    is it because i or p out of range of the array

    a referrence won't be faster in this case
    Last edited by Antigloss; 07-18-2005 at 09:16 AM.

  5. #5
    C/C++Newbie Antigloss's Avatar
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    try this if you intend to use referrence
    Code:
    void a(int (&i)[5][5])
    {}
    
    int main()
    {
        //what goes here?
    	int b[5][5] = { 0 };
    	a(b);
    }

  6. #6
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    I did create the matrix with the wrong size. I did use ** in the declaration at first but this error made me start playing with it, and I just got super confused.

    It seems to be working fine now.

    Thanks,

    AS.
    Everything is relative...

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