Evaluate triple summation in MATLAB

Hello, I want to the following equation . Here rpqs is the distance between two points which is calculated as given .Can anyone help me how I can calculate y . (xi,yi,zi) are the initial points.

[Jan]

Numerically or symbolically? What is "i"? Why to "q" and "s" not appear in the definition of "r_pqs"? Currently you could simply omit the two summations over q and s and multiply the result of the sum over p by 4.

Answer 1

[Rik]

And what have you tried so far?

You can do this with a triple nested loop, or with the meshgrid function.