Finding neighbours of an element in a matrix

Suppose that i have an element in a matrix and i need to find its neighbors and the distance of the neighbors...

i want to repeat this process for all elements in the matrix..

[Michael]

can you define what you mean by "distance"? Each element would have four neighbours each with distance 1. Is the matrix sparse?

[Bharathwaj]

actually..i have a surface containing paraboloids of different widths/sizes..i need to compute the distance between the centres of the paraboloids. A paraboloid might have 3 , 5 or 8 neighbours depending on where the paraboloid is located.

Answer 1

[Andrei Bobrov]

please try this is function

OR

here