MATLAB function to create randomized list of 2 values.

rand_sig.m

function [ sigmas ] = rand_sig( s1, s2, p, n )
% RAND_SIG Generate random list of sigmas
%   sigs = rand_sig(0.5, 0.45, 0.65, 100000);
%
% Arguments:
%   s1 = first standard deviation
%   s2 = second standard deviation
%   p  = probability (decimal) of s1 occurring
%   n  = number of items to generate

    if (s1 <= 0 || s1 >= 1)
        error('Sigma1OutOfRange', 'First sigma is not in (0,1):  %d', s1);
    end

    if (s2 <= 0 || s2 >= 1)
        error('Sigma2OutOfRange', 'Second sigma is not in (0,1):  %d', s2);
    end

    if (p < 0 || p > 1)
        error('POutOfRange', 'Probably of s1 is not in [0,1]:  %d', p);
    end

    if (n <= 0)
        error('NMustBePositive', 'N is not positive:  %d', n);
    end

    n1   = round(p * n);
    n2   = n - n1;

    a1   = ones(1,n1) .* s1;
    a2   = ones(1,n2) .* s2;

    aa   = cat(2,a1,a2);

    rnds = rand(1,n) * (n - 1) + 1;
    rnds = round(rnds);

    sigmas = aa(rnds);
    % sigmas = rnds;
end


% vim: sw=4 sts=4 ts=8 et