grad

Compute the gradient of a matrix. More...

Modules
	grad
	The C++ interface for grad.
	af_grad
	The C interface for Gradient along a dimension.

Detailed Description

Compute the gradient of a matrix.

grad computes the gradient of a matrix using a central difference along a given dimension. For an interior point in the matrix, \( n_i \), the central difference is computed as \( \frac{n_{i+1} - n_{i-1}}{2} \). For exterior points (those along the edge of the matrix), a one-sided difference is used.

array a; //a = [4  5  3]
         //    [8 10  9]
         //    [9 15 20]

array dx,dy;
grad(dcol,drow,a);


// Vertical gradient (along columns)
// dcol = [4   5   6]
//        [2.5 5 8.5]
//        [1   5  11]

// Horizontal gradient (along rows)
// drow = [1 -0.5 -2]
//        [2  0.5 -1]
//        [6  5.5  5]