Index exceeds the number of array elements

function Q32(x2,y2)

%aim of function to have two vectors x, y and each has a size of m. Order the vectors according to value (max 1st, lowest last) %Make a (m x m) matrix, where the diagonal terms have the Max values of vector x and the all other matrix elements have the Max %value of y.

x2 = x2(sort(x2, 'descend'));

y2 = y2(sort(y2, 'descend'));

lengx2 = length(x2);

lengy2 = length(y2);

n = lengy2;

for x = 1:1:lengx2

for y = 1:1:lengy2

if x==y

M(x,y) = x2(1);

else

M(x,y) = y2(1);

end

end

M(x,n) = x2(1);

n = n-1;

if n == 0

break

end

end

disp(M);

end

%This is my function and then i tried using it for these vectors

x2 = (1:1:8);

y2 = (1:2:16)';

Q32(x2,y2)

%the error reads

Index exceeds the number of array elements. Index must not

exceed 8.

Error in Q32 (line 3)

y2 = y2(sort(y2, 'descend'));

Error in testing (line 4)

Q32(x2,y2)

[Cris LaPierre]

Recreating the issue:

x2 = (1:1:8);
y2 = (1:2:16)';
Q32(x2,y2)

Index exceeds the number of array elements. Index must not exceed 8.

Error in solution>Q32 (line 8)
y2 = y2(sort(y2, 'descend'));

function Q32(x2,y2)
%aim of function to have two vectors x, y and each has a size of m. Order the vectors according to value (max 1st, lowest last) %Make a (m x m) matrix, where the diagonal terms have the Max values of vector x and the all other matrix elements have the Max %value of y. 
x2 = x2(sort(x2, 'descend'));
y2 = y2(sort(y2, 'descend'));
lengx2 = length(x2);
lengy2 = length(y2);
n = lengy2;
for x = 1:1:lengx2
    for y = 1:1:lengy2
        if x==y
            M(x,y) = x2(1);
        else
            M(x,y) = y2(1);
        end
    end
    M(x,n) = x2(1);
    n = n-1;
    if n == 0
        break
    end
end
disp(M);
end

Answer 1

[Cris LaPierre]

Your code is using the sorted values of y2 to index into y2. However, y2 only has 8 elements, but your values of y2 go up to 15. There error is because your index number cannot be higher than the number of elements in the vector.

y2 = (1:2:16)

y2 = 1×8

1 3 5 7 9 11 13 15

% works
y2(5)

ans = 9

% your error
y2(15)

Index exceeds the number of array elements. Index must not exceed 8.