find a values in matrix

1 view (last 30 days)
Tomas
Tomas on 23 Nov 2013
Edited: dpb on 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

Accepted Answer

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

More Answers (1)

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

Sign in to comment.

Categories

Find more on Data Clustering in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!