% rna_mar(n) generates n RNA bases with Markov dependence

function [Pi] = rna_mar(n)

A = [[0.180 0.274 0.426 0.120]; [0.171 0.368 0.274 0.188]; [0.161 0.339 0.375 0.125]; [0.079 0.355 0.384 0.182]];

Pi(1) = rando([1 1 1 1]/4);
for i=1:n-1,
  Pi(i+1) = rando(A(Pi(i),:));
end
show(Pi,'ACGU')
hist(Pi,4)

M = A^100;
fprintf('\nTheoretical frequencies of letters\n');
fprintf('%8.4f  ',M(1,:));
fprintf('\n');