MATLAB: Piece-wise linspace

array

Hi
I need to generate a vector (0's and 1's), when I'm given indices for the starting and endpoints of the 1's trains.
Example: m=zeros(1,10); starts=[1 5 9]; ends=[3 6 9];
the generated vector should be [1 1 1 0 1 1 0 0 1 0]
Any way of avoiding a loop? [starts(:):ends(:)] only looks at the first entry of the source vectors…
thanks Tozé

Best Answer

Do the sections overlap? If not, try this:
m         = zeros(1, 10);
starts    = [1 5 9];
ends      = [3 6 9];
m(starts) = 1;
m(ends)   = -1;
m         = cumsum(m);
If they sections are overlapping:
m         = zeros(1, 10);
p         = zeros(1, 10); 
starts    = [1 5 9];
ends      = [3 6 9];
m(starts) = 1;
m(ends)   = -1;
m         = cumsum(m);
p(m > 0)  = 1;
I cannot test this currently, so please keep care.
And perhaps this helps: FEX: interval merging.
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