# FORTRAN POPPAR Equivalent in Matlab

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Juan Navarro on 9 Jul 2021
Edited: Juan Navarro on 9 Jul 2021
Hello Matlab comunity, my question is what would be the equivalent to FORTRAN POPPAR function in Matlab?
According to gnc webpage, POPPAR(I) returns parity of the integer I, i.e. the parity of the number of bits set ('1' bits) in the binary representation of I. It is equal to 0 if I has an even number of bits set, and 1 for an odd number of '1' bits.
Thank you!

John D'Errico on 9 Jul 2021
sum(dec2bin(I) - '0')
Juan Navarro on 9 Jul 2021
Thank you John!

Walter Roberson on 9 Jul 2021
bitget() can be faster.
I = randi([0 2^32-1], 1, 1, 'uint32')
I = uint32 1734766993
timeit(@() mod(nnz(dec2bin(I)-'0'),2),0)
ans = 1.1998e-04
timeit(@() fold(@xor, dec2bin(I) - '0', 0), 0)
ans = 5.8975e-05
timeit(@() fold(@xor, bitget(I, 1:32), 0), 0)
ans = 3.8923e-05
timeit(@() mod(sum(bitget(I,1:32)),2),0)
ans = 3.4225e-06
Juan Navarro on 9 Jul 2021
Thank byou Walter, your help is very much appreciated!