Matrix — Array | CodeCogs

Dynamically allocates a zero-based 2D block (matrix) of data.

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Interface

#include <codecogs/computing/array/matrix.h>

using namespace Computing::Array;

template<class T>inline void free_matrix(T** Matrix)

Overview

Dynamically allocates a zero-based 2D block of memory. This memory block is continuous, and is in column then row order

For example, with an allocation of the type:

float **a = matrix<float>(2,3);

Then <tt>a[1][4] === a[2][0]</tt>.

The opposite of this function is free_matrix .

Example 1

#include <cstdio>
#include <codecogs/computing/array/matrix.h>
using namespace Computing;

int main()
{
  // allocate some memory, 5 rows, 3 columns
  int **A = Array::matrix<int>(5,3);

  // initialize with some data (multiplication table)
  for(int j=0; j<5; j++)
    for(int i=0; i<3; i++)
      A[j][i] = (i+1)*(j+1);

  // convert to one-dimensional array
  int *B = A[0];
  for(int i=0; i<15; i++)
    printf(" %d", B[i]);

  // tidy up
  Array::free_matrix(A);
}

Output:

1 2 3 2 4 6 3 6 9 4 8 12 5 10 15

Parameters

Rows

The 2nd dimension of a matrix.

Columns

The 1st (primary) dimension of a matrix.

You should always use free_matrix to de-allocate memory allocated to this structure.

FUNCTION

free_matrix

Removes any dynamically allocated memory for a 2D structure from the stack. This function is usually used on data structures created using matrix<>, though it can also be used on other 2D types, so long as the memory is continuously allocated.

The opposite of this function is matrix

Parameters

Matrix

is the 2D data structure to delete.

Author

Will Bateman (February 2005)