find a values in matrix

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Tomas
Tomas il 23 Nov 2013
Modificato: dpb il 24 Nov 2013
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

Risposta accettata

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

Più risposte (1)

dpb
dpb il 23 Nov 2013
Modificato: dpb il 23 Nov 2013
val=2.3926;
A=H(abs(H-val)<1.e-5);
NB the "fuzzy" comparison to avoid FP precision problems
  2 Commenti
Tomas
Tomas il 23 Nov 2013
Modificato: Tomas il 23 Nov 2013
little easier ?
will it work on different numbers in the matrix?
dpb
dpb il 23 Nov 2013
Modificato: dpb il 24 Nov 2013
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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