# Convert near zero complex parts to 0

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Paul Hoffrichter on 1 Apr 2021
In R2020a, I took a complex vector and converted near zero parts to zero. It took two long lines to do it. Can it be done in one line and not so long lines?
yy
yyFix = yy;
yyFix( abs( real(yyFix) ) < 1e-10 ) = 1j * imag(yyFix( abs( real(yyFix) ) < 1e-10 ) );
yyFix( abs( imag(yyFix) ) < 1e-10 ) = real(yyFix( abs( imag(yyFix) ) < 1e-10 ));
yyFix
The good output is:
yy =
1 + 0i
6.12323399573677e-17 + 1i
-1 + 1.22464679914735e-16i
-1.83697019872103e-16 - 1i
yyFix =
1 + 0i
0 + 1i
-1 + 0i
0 - 1i
I see that eps = 2.22044604925031e-16, but I would like to zero out the real and/or imag parts that are not as close to zero as eps.
<<EDIT 2021-04-01>> The +/-1 yy values can have arbitrary amplitudes. I assume that length(yy) > 1e8 for each signal section and/or input file.

Alan Stevens on 1 Apr 2021
Does the following do what you want
yyFix = round(yy*10^n)/10^n;
where you choose n as desired.
Paul Hoffrichter on 2 Apr 2021
Thanks. I will keep this Mex thought in mind and ask another question some time since I don't get how that would work. Another day. :)