function to find arg max

Hello, i have a problem. please help

we have x1, x2, x3, x4 are different functions of ' t ' and f1, f2, f3, f4 are also different.

t=1:50;
 C1=f1(x1)
 C2=f2(x2)
 C3=f3(x3)
 C4=f4(x4)
for t=1:50
   C=max([C1 C2 C3 C4])
end

how to find x which cause C max?

Answer 1

[Star Strider]

You can get the index of the maximum returned by max by asking the function to return it. From the documentation:

• [M,I] = max(_) finds the indices of the maximum values of A and returns them in output vector I, using any of the input arguments in the previous syntaxes. If there are several identical maximum values, then max returns the index of the first one.

[son]

these are 4 different functions so it is impossible to use MAX

[Star Strider]

Your question and code lack some necessary information. You are iterating through ‘t’, but your ‘f1...f4’ functions are of ‘x1...x4’ which are different functions of ‘t’ but not explicitly so in the code you posted to create ‘C1...C4’.

I got the impression that you intended to create one value for ‘C1...C4’ in each iteration of your loop, so then each ‘C1...C4’ is a scalar.

I inferred:

for t = 1:50
     C1=f1(x1(t));
     C2=f2(x2(t));
     C3=f3(x3(t));
     C4=f4(x4(t));
     [C,I]=max([C1 C2 C3 C4]);
     Cmax(t) = [C I];
end

so that for every value of ‘t’ you would get the maximum as ‘C’ and the function that produced it in ‘I’.

If that is not what you are doing in your loop, you need to provide a more specific description.