find a values in matrix

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Tomas
Tomas 2013-11-23
编辑： dpb 2013-11-24
I have matrix H[ 0 2.3926
2.3926 0]
I want to find value in matrix H, 2.3926 and store it in a variable A

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采纳的回答

Azzi Abdelmalek
Azzi Abdelmalek 2013-11-23
Maybe you are looking for the location
H=[ 0 2.3926
2.3926 0]
[ii,jj]=find(H==2.3926)

更多回答（1 个）

dpb
dpb 2013-11-23
编辑：dpb 2013-11-23
val=2.3926;
A=H(abs(H-val)<1.e-5);
NB the "fuzzy" comparison to avoid FP precision problems
  2 个评论
Tomas
Tomas 2013-11-23
编辑：Tomas 2013-11-23
little easier ?
will it work on different numbers in the matrix?
dpb
dpb 2013-11-23
编辑：dpb 2013-11-24
Not sure what the question is, precisely. Of course the comparison can be any value or range of values. There are times when owing to FP rounding find(x==val) won't return what is naively expected.
You can always write
A=H(H==2.3926);
and for some cases you'll find joy, in others "not so much"
Look up "logical addressing" in the documentation for more detail of how this works.

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