How can I mix two arrays?

Given A=[1 3 5 7 9] and B=[2 4 6 8], how can I create C=[1 2 3 4 5 6 7 8 9]?

Answer 1

[Youssef Khmou]

This question is general due to the variation of array dimensions, however for a particular case you described, vectors A and B can be mixed by single loop, so the following scheme is valid only when dim(A)=dim(B)+1 as in the example :

 A=[1 3 5 7 9];
 B=[2 4 6 8];
 n=min(length(A),length(B));
 C=[];
 for t=1:n    
    C=[C A(t) B(t)];
 end
 C=[C A(end)];

[Alex Strongholm]

That's it, thank you very much

[Stephen23]

This answer is very poor use of MATLAB.

The use of a for loop and concatenating scalar values onto the end of with every iteration is poor coding practice in MATLAB. If the arrays are large, then this will be slow as MATLAB keeps expanding the array and copying it to new memory. One solution is to preallocate the array.

For a much neater and simpler solution see my answer below.

[Stephen23]

For those who are interested, some references as to why array concatenation in a loop is poor coding practice in MATLAB:

http://www.mathworks.com/matlabcentral/answers/99124-how-do-i-pre-allocate-memory-when-using-matlab

http://www.mathworks.com/matlabcentral/fileexchange/8334-incremental-growth-of-an-array--revisited

http://web.cecs.pdx.edu/~gerry/MATLAB/programming/performance.html

Answer 2

[Stephen23]

This can be done simply using indexing, without any loops:

>> A = [1,3,5,7,9];
>> B = [2,4,6,8];
>> C(1:2:2*numel(A)) = A;
>> C(2:2:end) = B

C =

       1     2     3     4     5     6     7     8     9

This solution also assumes that numel(A)==numel(B)+1.

Most importantly, for larger arrays this code will be much faster than the accepted solution, so it is the most universal solution.