Building matrix using vectors?Easy question.

P{1}, P{2}...P{n} are my vectors.

And I want P{1} is first row of my matrix.P{2} second row of my matrix. How can I do this?

Answer 1

[Iain]

Depending what you have:

 1) matrix = [row_vector1;row_vector2; ... row_vectorn];
 2) matrix = [col_vector1, col_vector2, ... col_vectorn]';
 3) matrix(row_number1,:) = vector1;
    matrix(row_number2,:) = vector2;
    matrix(row_number3,:) = vector3;

Answer 2

[Jos (10584)]

Your question suggests you have a cell array with vectors, so you can/should make use of comma-separated list expansion. If all vectors are of the same length, take a look at CAT

P = {1:3,11:13,21:23} % row vectors
M  = cat(1,P{:})

If they have different lengths, you might be interested in PADCAT, which pads the vectors with NaNs

P = {[1:3].' , [11:15],' , [21:24],'} % column vectors
M = padcat(P{:}) ;

PADCAT can be found here: http://www.mathworks.com/matlabcentral/fileexchange/22909-padcat

Answer 3

[heybatollah jokar]

*assume you have n vectors with same length which stored in P as follows: P={[vector 1],[vector 2],[vector 3],...}

now using simple code:*

for i=1:length(P)

A(i,:)=P{i}

end

as an example %================================

clc clear all P={[1 2 3],[4,5,6],[7 8 9]}; for i=1:length(P)

A(i,:)=P{i};

end

disp(A) %==============================

% result:

     1     2     3
     4     5     6
     7     8     9

[Jos (10584)]

why use a for-loop if you have CAT ... (see the answer above for an example)