Output only numbers with complex conjugate

Lets say I have an Array

a = [1+i*0.1, 1-i*0.1, 5-i*0.1, 10+i*0.2, 10-i*0.2]

which only contains complex numbers. I would like my output to only contains those numbers which have an corresponding complex conjugate inside the array e.g.

    out = [1+i*0.1 10+i*0.2]

The output could also just contain the complex conjugate, but not both

Any help is greatly appreciated.

Answer 1

[Bruno Luong]

a(ismember(a,conj(a))&imag(a)>=0)

[Ko Fa]

Thank you!

Answer 2

[Rik]

a = [1+1i*0.1, 1-1i*0.1, 5-1i*0.1, 10+1i*0.2, 10-1i*0.2];
b=conj(a);
c=b(ismember(b,a));
d=real(c)+1i*abs(imag(c));
e=unique(d)

e = 1×2

1.0000 + 0.1000i 10.0000 + 0.2000i

●

(the displaying seems to have some issues, but it is indeed the vector you describe)

[Star Strider]

See if the cplxpair function can help!

[Rik]

Wouldn't that just return an error when used on a? Or do you mean this?

a = [1+1i*0.1, 1-1i*0.1, 5-1i*0.1, 10+1i*0.2, 10-1i*0.2];
b=conj(a);
c=b(ismember(b,a));
d=cplxpair(c);
e=d(2:2:end)

[Ko Fa]

Thank you Rik! This is working perfectly fine.

I was just confused at first, thinking my numbers are getting messed up somehow. I just now realized this is filling "e" in ascending order.

[Rik]

You can also use the 'stable' option in unique if you want to preserve the original order.

[Ko Fa]

True! Thank you.