How do I find indexes of three for-loops of maximum value of function with three indexes?

clear all

clc

xx=0:1:5;

yy=0:1:7;

zz=-5:1:1;

for i=1:length(xx)

x=xx(i);

for j=1:length(yy)

y=yy(j);

for k=1:length(zz)

z=zz(k);

w(k,j,i)=x^2-y^3+z;

end

end

end

Answer 1

[Dyuman Joshi]

The MATLAB approach to generate the output would be -

(Edit - corrected some typos)

xx=0:1:5;
yy=0:1:7;
zz=-5:1:1;

%Note that the order of input to ndgrid() is according to the indices
%of w in the for loop - (k,j,i) 
[Z,Y,X]=ndgrid(zz,yy,xx);
W = X.^2 - Y.^3 + Z;

%Get the maximum value in W and the corresponding linear index
[maxval,maxidx] = max(W,[],'all')

maxval = 26

maxidx = 287

%Get the indices for each dimension via ind2sub()
[ix,jx,kx]=ind2sub(size(W),maxidx)

ix = 7

jx = 1

kx = 6

Note that max will return the linear index that corresponds to the first occurence of maximum in the array.

%Comparison for the output obtained from ndgrid
for i=1:length(xx)
    x=xx(i);
    for j=1:length(yy)
        y=yy(j);
        for k=1:length(zz)
            z=zz(k);
            w(k,j,i)=x^2-y^3+z;
        end
    end
end
isequal(W,w)

ans = logical
   1

[GULZAR]

Thank You, Its working perfectly......