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function [T,Z] = mk_stochastic(T)
% MK_STOCHASTIC Ensure the argument is a stochastic matrix, i.e., the sum over the last dimension is 1.
% [T,Z] = mk_stochastic(T)
%
% If T is a vector, it will sum to 1.
% If T is a matrix, each row will sum to 1.
% If T is a 3D array, then sum_k T(i,j,k) = 1 for all i,j.
% Set zeros to 1 before dividing
% This is valid since S(j) = 0 iff T(i,j) = 0 for all j
if (ndims(T)==2) && (size(T,1)==1 || size(T,2)==1) % isvector
[T,Z] = normalise(T);
elseif ndims(T)==2 % matrix
Z = sum(T,2);
S = Z + (Z==0);
norm = repmat(S, 1, size(T,2));
T = T ./ norm;
else % multi-dimensional array
ns = size(T);
T = reshape(T, prod(ns(1:end-1)), ns(end));
Z = sum(T,2);
S = Z + (Z==0);
norm = repmat(S, 1, ns(end));
T = T ./ norm;
T = reshape(T, ns);
end
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