Documentation

The C++ interface for grad. More...

 void grad (array &dcols, array &drows, const array &in)

## Detailed Description

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;
// dcol = [4 5 6]
// [2.5 5 8.5]
// [1 5 11]