MATLAB: Create intermediate indices from vectors of start and stop indices

indexindexing

Is there a fast way to create a vector of indices taking as an input two vectors containing the start and stop indices?
I want:
a = [2 7 9 17]; b = [4 7 12 17];
c = fun(a,b) = [2 3 4 7 9 10 11 12 17];

Best Answer

See Bruno's FEX: mcolon.
Are the values always integers? Can the intervals overlap? These details are very important for the implementation.
[EDITED] If the intervals do not touch eachother - in other words: if there is always an element between them:
a      = [2 7 9 17];
b      = [4 7 12 17];
k(b+1) = -1;
k(a)   = 1;
c      = find(cumsum(k));
For large arrays it would help to save time, if CUMSUM handle INT8 vectors - unfortunately it doesn't.
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