How to count number of ones and zeros in a binary number?

I am having some set of binary numbers. I need to count the number of ones and zeros in each binary number. If a binary number has even number of ones then the output has to be '1' or it has to be '0'. Thank you in advance.

Example:

A=1100

B=0100

output of A =1

output of B = 0

Answer 1

[Davide Masiello]

I will assume that your binary numbers are stored as a character array, which is how Matlab normally works, e.g.

A = dec2bin(20)

A = '10100'

B = dec2bin(21)

B = '10101'

Now in the example above, A has an even and B has an odd number of ones respectively.

your desired output can be easily obtained with

1-mod(nnz(A=='1'),2)

ans = 1

1-mod(nnz(B=='1'),2)

ans = 0

[ASHA PON]

Thank you for the reply. Actually i am having an array of 15 binary numbers and i need to apply the above mentioned concept to each numbers.

Example:

A=[ 1110, 0111, 0110, 1111]

Expected output:

B= 0, 0, 1, 1

[Davide Masiello]

A= [1110, 0111, 0110, 1111];
B = 1-mod(sum(num2str(A') == '1',2),2)

B = 4×1

0 0 1 1

[ASHA PON]

Thank you for the reply. This is what i needed.

Answer 2

[Chunru]

% if you use char to represent binary numbers
A='1100';
mod(sum(A=='1'), 2) == 0

ans = logical
   1

% if you use double to represent binaray numbers, you can do the conversion
% first
A = 1100;
A = num2str(A)

A = '1100'

mod(sum(A=='1'), 2) == 0

ans = logical
   1

[Davide Masiello]

Not sure you can convert from double to binary (char array) for any given number.

A = 0100;
A = num2str(A)

A = '100'

Or am I missing something?

[Chunru]

To count number of 1, it is perfectly fine.

If you do need to get 0100, you have to specify the number of digits and leading 0s using sprintf:

A = 0100;
A = sprintf('%04d', A)

A = '0100'

[Davide Masiello]

Good point.

[ASHA PON]

Thank you for the reply. Actually i am having an array of 15 binary numbers and i need to apply the above mentioned concept to each numbers.

Example:

A=[ 1110, 0111, 0110, 1111]

Expected output:

B= 0, 0, 1, 1