issues with function find()
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I am using find() to find the index of a number in a matrix, but it is returning an empty matrix yet am sure that the number is part of that matrix. Here is the code
tr=0:.1:20;
b=find(tr==2.4)
and it is returning
b =
Empty matrix: 1-by-0
Please I need your help. What am I doing wrong or what should I do instead?
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More Answers (1)
Brian B
on 2 Mar 2013
Edited: Brian B
on 2 Mar 2013
Try
tr=0:.1:20;
tr = round(tr*1e12)/1e12;
b=find(tr==2.4)
This is a problem with finite precision. See the explanation offered at http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F.
1 Comment
Brian B
on 2 Mar 2013
Actually, if you're using non-integer numbers, a better method is
b= find(abs(tr - 2.4)<1e-12)
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