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

Contents

Interface Function Documentation Page Comments

Interface

#include <codecogs/array/matrix.h>

using namespace Array;

	template<class T>T**	matrix (long Rows, long Columns)[inline] Dynamically allocates a zero-based 2D block (matrix) of data.
	template<class T>void	free_matrix (T** Matrix)[inline] Frees from memory a 2D block of dynamically allocated data.

Function Documentation

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 a[1][4] === a[2][0].

The opposite of this function is free_matrix .

Example

#include <codecogs/array/matrix.h>
 
int main()
{
  // allocate some memory, 5 rows, 3 columns
  int **A = Array:matrix<int>(5,3);

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

Note:

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

Parameters:

Rows	The 2nd dimension of a matrix.
Columns	The 1st (primary) dimension of a matrix.

Authors:

Will Bateman (February 2005)

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.

Authors:

Will Bateman (February 2005)