how to separate odd and even elements of a matrix with out using for or while loops.

a function that takes a matrix A of positive integers as an input and returns two row vectors. The first one contains all the even elements of A and nothing else, while the second contains all the odd elements of A and nothing else, both arranged according to column-­‐major order of A. without using for loops or while loops.

i am using this approach, where r vector contains the row position of odd elemets and c vector contains the coloumn position of odd elements

function [o e] = separate_by_two(A)
B = mod(A,2)
[r c] = find(B);

now dont know how to make a vector conatining all the odd and even elements.

Answer 1

[Andrei Bobrov]

t_odd = rem(A,2) ~= 0;
namber_odd = A(t_odd);
namber_even = A(~t_odd);

[Maha Almuaikel]

what does "~" do?

[Ugo Bruzadin Nunes]

This is a beautiful answer. ~ means opposite. The first line collects all divisions by 2 that the remainders are not 0, makes into a bollean 1 or 0 array. The second line gets all the numbers that are odds, the second gets all the numbers that are not odds.

[Jan]

@Maha Almuaikel: ~ is the not() operator - see: not

Answer 2

[Thomas Nguyen]

Code:

function[] = sortEvenOdd(A)
%This is the main function:
[Aodd,Aeven] = sort(A);                %calling the local func
disp('Even numbers of matrix A: ');    %display message
disp(Aeven);                           %display the even row array
disp('Odd numbers of matrix A: ');     %display message
disp(Aodd);                            %display the odd row array
end%sortEvenOdd()

function[Aodd,Aeven] = sort(A)
%This is the local function:
even = rem(A,2) == 0;     %even is a logical array that takes value 1 for every even int element of A (else 0)
Aeven = A(even);          
Aodd = A(~even);         
end%sort()

Sample input for A (Prefered: entered in the command window): A=[1 4 5 6 2 6 7 3 64 5 4 1 7] or A = randi([1 50],1,15)

Answer 3

[Walter Roberson]

http://www.mathworks.com/matlabcentral/fileexchange/2006-isodd

are_they_odd = arrayfun(@isodd, A);
odd_ones = A(are_they_odd);
even_ones = A(~are_they_odd);