Hi guys how can swap the max value and min value for a matrix ?

I want to swap max and min value to any matrix

[Guillaume]

What should be done if there are several elements that are equal to the max or the min?

[Ali Mohammad]

now I need to learn how to swap if there is only 1 max and 1 min

but if you have the answer to all cases that would be very useful too

[Rik]

This sounds a lot like homework. Is it?

[Ali Mohammad]

Yes it is for homework

new to matlab and programming in general

[John D'Errico]

Can you find the max value? (help max)

Can you find the min value? (help min)

Or, can you use the sort function? Why not read the help?

So come on. Make an effort. This is your homework, not ours. There must be a zillion ways to do this.

[Ali Mohammad]

i know how to find the max value and min value

and I managed to make a loop looking for a max value and min value but I tried to find the way to swap the values and i could'nt that is why I came here for someone to guide me

how could you tell I didn't make any effort ?

[madhan ravi]

upload your code

[Mark Sherstan]

Post your code so we can direct you.

[Ali Mohammad]

The goal is to program the matlab to swap max and min value in a matrix

clc
clear all
 A=[1 2 3; 4 5 6;4 7 8]
c=max(max(A))
g=min(min(A))

for i=1:3
    for j=1:3
        if A(i,j)==max(max(A))
            A(i,j)=g;
            
        end
    end
end
for i=1:3
    for j=1:3
        if A(i,j)==min(min(A))
            A(i,j)=c;
            
        end
    end
end
A

Answer 1

[madhan ravi]

No loops needed:

A=[1 2 3; 4 5 6;4 7 8]
[value,idx]=max(A(:))
[val,iddx]=min(A(:))
A(idx)=val;
A(iddx)=value

Answer 2

[Stephen23]

>> A = randperm(9)
A =
   5   6   1   3   7   8   4   9   2
>> [~,idx] = max(A(:));
>> [~,idn] = min(A(:));
>> A([idx,idn]) = A([idn,idx])
A =
   5   6   9   3   7   8   4   1   2

Answer 3

[Image Analyst]

I suggest you use my vectorized method using min(), max(), and find(). The other solutions I've seen so far will not work in the general situation where your max or min occurs more than once since min() and max() do not (for some weird reason) return ALL indexes):

A = [1 1 3 4 9 9 ; 4 1 1 4 9 9] % Max and min occur in multiple places.
minValue = min(A(:))
maxValue = max(A(:))
minIndexes = find(A == minValue)
maxIndexes = find(A == maxValue)
A(minIndexes) = maxValue;
A(maxIndexes) = minValue