Cody: Problem 30 - function Sortrows

Hi,

i'm "solving" number 30 cody's problem.

I think to solve that whit sortrows function.

If I have a z vector:

j = sqrt(-1);
z = [-4 6 3+4*j 1+j 0];

my funtion is:

function z = complexSort(z)
    z(2,:)=sqrt(real(z).^2+imag(z).^2);
    z=sortrows(z',-2);
    z=z(:,1);
end

End it return the result

z =

   6.0000             6.0000          
   3.0000 - 4.0000i   5.0000          
  -4.0000             4.0000          
   1.0000 - 1.0000i   1.4142          
        0                  0

The question is: why imagine part in input is positive e sortrows trasform it in negative?

best regards

Marco

Answer 1

[Ryan]

You were taking the complex conjugate of z. Be careful whenever you use ' to transpose in Matlab!

function z = complexSort(z)
    z(2,:)=sqrt(real(z).^2+imag(z).^2);
    z=sortrows(z.',-2);
    z=z(:,1);
end

That should work for you.

[Sean de Wolski]

+1. Note the . in front of the '

doc transpose %v.
doc ctranspose

Answer 2

[Fatih Atilla PINAR]

function zSorted = complexSort(z)

zSorted = sort(z,2,'descend');

end