function rp=cosmo_randperm(n,varargin)
% generate random permutation of integers
%
% cosmo_randperm(n[,count][,'seed',seed])
%
% Inputs:
% n Maximum value of output
% count (optional) number of elements to return; count
% must not be larger than n.
% Default: count=n
% 'seed',seed (optional) use seed for determistic
% pseudo-random number generation. If provided
% then subsequent calls to this function with the
% same input arguments will always give the same
% output. If not provided, then subsequent calls
% will almost always give different outputs
%
% Output:
% rp row vector with count elements, with all
% numbers in the range 1:n. Numbers are sampled
% from 1:n without replacement, in other words rp
% does not contain repeats.
%
