Find elements meeting any of a number of criteria

Question

I am trying to find the indices of elements in a vector that correspond to another vector, preferably without using loops. For example, my input might be:

DJ         


        

Answer 1

Approach #1

You can avoid find by reversing the places of DJiSet and JiSet inside ismember and then use the second output that gives us the matching indices -

[~,out] = ismember(DJiSet,JiSet)

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Approach #2

Loopy approach catering to the specific conditions set in the question could be tried out, not sure if this will be more efficient though -

intv_idx = zeros(1,numel(DJiSet));
intv_idx(1) = find(JiSet==DJiSet(1),1);
start = intv_idx(1)+1;
for k = 2:numel(DJiSet)
    idx = find(JiSet(start:end)==DJiSet(k),1);
    start = idx+start;
    intv_idx(k) = idx;
end
out = cumsum(intv_idx);