How do I find the indices of the maximum (or minimum) value of my matrix?
3 715 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
MathWorks Support Team
le 7 Oct 2009
Commenté : Steven Lord
le 18 Août 2022
The 'find' command only returns the indices of all the non-zero elements of a matrix. I would like to know how to find the indices of just the maximum (or minimum) value.
Réponse acceptée
MathWorks Support Team
le 28 Mar 2022
Modifié(e) : MathWorks Support Team
le 17 Nov 2021
The "min" and "max" functions in MATLAB return the index of the minimum and maximum values, respectively, as an optional second output argument.
For example, the following code produces a row vector 'M' that contains the maximum value of each column of 'A', which is 3 for the first column and 4 for the second column. Additionally, 'I' is a row vector containing the row positions of 3 and 4, which are 2 and 2, since the maximums for both columns lie in the second row.
A = [1 2; 3 4];
[M,I] = max(A)
For more information on the 'min' and 'max' functions, see the documentation pages listed below:
To find the indices of all the locations where the maximum value (of the whole matrix) appears, you can use the "find" function.
maximum = max(max(A));
[x,y]=find(A==maximum)
0 commentaires
Plus de réponses (5)
Shakir Kapra
le 20 Avr 2015
Modifié(e) : Shakir Kapra
le 20 Avr 2015
[M,I] = min(A)
where M - is the min value
and I - is index of the minimum value
Similarly it works for the max
0 commentaires
Andrew Teixeira
le 1 Oct 2019
How about just:
A = magic(5);
[Amins, idx] = min(A);
[Amin, Aj] = min(Amins);
Ai = idx(Aj);
where your final matrix minima is located at [Ai, Aj]
0 commentaires
Juanith HL
le 8 Oct 2019
A = [8 2 4; 7 3 9]
[M,I] = max(A(:)) %I is the index maximun Here tu can change the function to max or min
[I_row, I_col] = ind2sub(size(A),I) %I_row is the row index and I_col is the column index
1 commentaire
Steven Lord
le 18 Août 2022
If you can use linear indices, instead I would recommend:
A = [8 2 4; 7 3 9];
[X, ind] = max(A, [], 'all', 'linear')
This will tell us the maximum value in A is 9 and it is located in element 6 of A.
ANKUR KUMAR
le 19 Sep 2017
Use this as a function and type [x,y]=minmat(A) to get the location of the minimum of matrix. for example:
>> A=magic(5)
>> [a,b]=minmat(A)
a =
1
b =
3
Save this as a function in your base folder and use it.
function [ a,b ] = minmat( c )
as=size(c);
total_ele=numel(c);
[~,I]=min(c(:));
r=rem(I,as(1));
a=r;
b=((I-a)/as(1))+1;
if a==0
a=as(1);
b=b-1;
else
a=r;
b=b;
end
end
1 commentaire
Steven Lord
le 6 Sep 2020
Once you've stored this code in a file named minmat.m (see this documentation page for the basics of defining a function) you can call this like any other MATLAB function (as shown on this other documentation page.)
Voir également
Catégories
En savoir plus sur Manage Products dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!