Creating Matrix using two vectors and scalar

Hi guys,

I need your help in solving the following problem: Given a row vector, a column vector and an index create a matrix in the following manner (look at example) without using cell arrays and the implementation should be fast:

Remark: "index" correspond to the row column!

Thanks in advance.

[Geoff Hayes]

Jack - is this homework, and if it is, what have you tried so far?

[jack]

it is not a homework, and i have tried to create column vector to concate them to get the desired matrix.

[Geoff Hayes]

Please post/attach your code so that we can see what you have attempted and offer some suggestions on how you can arrive at the correct answer.

[jgg]

Try looking at the repmat function. I think it should solve your problem.

[jack]

Thank you very much, i have solved it using repmat.

Answer 1

[Andrei Bobrov]

function out = fun1(r,c,ii)
    out = ones(numel(c),1)*r;
    out(:,ii) = c;
end

use

r = [2 7 3 5];
c = [2;7;10];
ii = 2;

out = fun1(r,c,ii);

Answer 2

[Kirby Fears]

jack,

Please read the repmat() documentation to understand its interface and functionality. With repmat, you can stack copies of your row vector into a matrix.

You should be able to determine how many copies of your row vector to stack based on the length() or size() of your column vector.

From there, you just have to insert the column vector into the appropriate column using array indexing .