Directly using Index of max value without storing
2 views (last 30 days)
Show older comments
Matthew Knights
on 26 Jul 2016
Commented: Matthew Knights
on 26 Jul 2016
Hi,
I want to use the index of a maximum value in a vector directly without storing it as a variable. i.e:
I have a vector X = [1 3 2 9 2 1], and a vector Y = [10 20 30 50 60 70] and I want to extract the value in Y corresponding to the max value in X. I know I can use:
[M,I] = max(X); then
Value = Y(I);
But I can't work out how to do this in a single line without storing the value of "I", to acheive something like:
Value = Y(...index of max value of X...)
Any help greatly appreciated.
Thanks,
Matt
2 Comments
Stephen23
on 26 Jul 2016
@Matthew Knights: what output do you want if there are two identical maximum values ? E.g.:
X = [1 3 2 9 2 9]
Y = [10 20 30 50 60 70]
value = ???
Accepted Answer
Guillaume
on 26 Jul 2016
This is one of the downside of matlab's syntax. It is not possible to chain expressions that use anything but the 1st return value. You have to use a temporary variable.
More Answers (1)
Andrei Bobrov
on 26 Jul 2016
out = Y(max(X)==X)
4 Comments
Guillaume
on 26 Jul 2016
Certainly not! There's no guarantee that the value in Y would be the same for identical max values in X.
This would work:
Y(find(max(X) == X, 1))
as long as X and Y are vectors. Reproducing the same behaviour for matrices would be harder.
See Also
Categories
Find more on Matrix Indexing in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!