What is the main difference between gradient command and diff comand

x = [1, 5, 10, 17, 30];

gradient_x = gradient(x);

disp(gradient_x)

Result:4.0000 4.5000 6.0000 10.0000 13.0000

In this code I am getting this result.How it is actaully calculating the result and does this show the slope?

Answer 1

[Torsten]

gradient: 5-1,(10-1)/2,(17-5)/2,(30-10)/2,30-17

diff: 5-1,10-5,17-10,30-17

Both are approximations to the slope of x if the spacing of the independent variable is 1.

[Mashrur Zawad]

Hlw, I got it.Can you please tell me why (10-1)/2,(17-5)/2,(30-10)/2 has divide it with 2 whereas 1st and last 1 is with 1?This question might sound silly but I need to grab how it is working as I have to use this command to a largse set of data.

[Dyuman Joshi]

From the documentation of gradient -

gradient calculates the central difference for interior data points. For example, consider a matrix with unit-spaced data, A, that has horizontal gradient G = gradient(A). The interior gradient values, G(:,j), are

G(:,j) = 0.5*(A(:,j+1) - A(:,j-1));

The subscript j varies between 2 and N-1, with N = size(A,2).

gradient calculates values along the edges of the matrix with single-sided differences:

G(:,1) = A(:,2) - A(:,1);
G(:,N) = A(:,N) - A(:,N-1);