🚀 go-pugleaf

In article <1992Nov5.203939.1323@fcom.cc.utah.edu> tim@osiris.usi.utah.edu (Tim Burns 581-4439) writes:
>memory dynamically.  Right now, when I allocate my array using the 
>standard array allocation:  double A[L][M], where L and M are constants,

What you see is that `A' has a type compatible with `(double *)',
whereas what the _Numerical_Recipes_ method does is create
`m' as compatible with `(double **)'.

All you need to do is allocate enough space for the
two-dimensional array.  C's array-memory mapping is flat,
in row-major order.

You want L rows of M columns of doubles, so you need

	m = (double *) malloc ( L * M * sizeof(double) );

and now `m' is compatible with `A'.

Accesses to `m' can now be made using C's array-access syntax;
That is,

	int row, col;
	...

	m[row][col]

gives the number at row and col.

	m[row][col+1]

gives the next number in `m', and

        m[row+1][col]

gives the number in the next row, i.e., L elements away from
the number in this row of `m'.

				--Blair
				  "Isn't this just a little basic?"