Gradient of an image

I want to extract gradient from an image. Can I do in Matlab using the following command?

ims=imread('A.png');

Rx = ims(:,1:end-1,1) - ims(:,2:end,1);

Gx = ims(:,1:end-1,2) - ims(:,2:end,2);

Bx = ims(:,1:end-1,3) - ims(:,2:end,3);

Ry = ims(1:end-1,:,1) - ims(2:end,:,1);

Gy = ims(1:end-1,:,2) - ims(2:end,:,2);

By = ims(1:end-1,:,3) - ims(2:end,:,3);

Pl = [[Rx(:),Gx(:),Bx(:)];[Ry(:),Gy(:),By(:)]];

Answer 1

[Image Analyst]

I'd simply use imgradient() or imgradientxy().