zipf_rand function not working

When I use the zipf_rand function as 'fN = zipf_rand(100,1,100)' the following error is shown:

Undefined function or variable 'zipf_rand'.

Can someone guide me on how I can resolve this issue.

[Rik]

That function is not a native Matlab function, but a function from the File Exchange. Did you make sure the m file of that function is on the search path? That can be any path you edit in the settings, or your current folder.

[Adeena Naeem]

Many thanks!