smallest n such that vector(n) < a
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hi,
is there a efficient way that given a vector "vec" whose elements are monotonic increasing i can find the smallest index such that vec(n) < a. where "a" is some given value.
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Image Analyst
on 21 Dec 2012
Edited: Image Analyst
on 21 Dec 2012
The smallest/lowest/first index will be the first one (index = 1) like Azzi said. But that is a trivial case and I think you actually mean the highest index, and that is what Wayne gave you code for. Like m = [11 12 13 14 15] and the value = 13.1. The lowest index where m < 13.1 is 1 and the highest is 3. Please confirm/clarify.
Accepted Answer
Wayne King
on 21 Dec 2012
Edited: Wayne King
on 21 Dec 2012
x = 1:100;
a = 50;
[val,idx] = find(x<a,1,'last');
idx is the index of vec() and val is the value
If the values in the vector are monotonically increasing as you describe, then the 'last' option gives you the last index. Did you really mean you want the "smallest"?
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More Answers (1)
Azzi Abdelmalek
on 21 Dec 2012
Edited: Azzi Abdelmalek
on 21 Dec 2012
v=[10 12 4 5 9 20]
idx=find(v<5,1)
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