There is (to my knowlegde) no matlab function for this, but with a little sorting and geometry this is no problem.
% input matrix
X = [0 0 0 1 0;0 0 0 1 0;0 1 1 1 0;0 1 0 0 0;0 1 0 0 0];
% all filled positions in matrix
[r, c] = ind2sub(size(X), find(X));
% coordinates in 2d, sorted by row index
coord = sortrows([r, c]);
% path along coordinates
coordpath = zeros(size(coord));
% start at first coordinate
coordpath(1,:) = coord(1,:);
coord(1,:) = [];
% loop over all coordinates
for n = 2:length(r)
% vector pointing from last coordinate in path to all other coordinates
vec = coord - ones(size(coord, 1), 1) * coordpath(n-1, :);
% distance to other coordinates
dist = sqrt(sum(vec.^2, 2));
% nearest coordinate has minimum distance
nextcoord = find(min(abs(dist)) == abs(dist));
% add to path
coordpath(n,:) = coord(nextcoord, :);
% remove from coordinate list
coord(nextcoord, :) = [];
end
