How to make a column matrix from multi-dimensional matrix with several rows

Hello, allow me inquire something little. Suppose i have matrix A which is100 by 30 matrix. I want to make a n by 1 matrix by transposig each row from A then concatenating to form B. Example;

A=[1 2 3 4 5;60 5 7 89 9;4 5 7 8 9;6 80 32 12 11];

B=[A(1,:);A(2,:);A(3,:);A(4,:)];

Now the sample program above was simple becaue it involved only a few row which can easily be computed, supposei have larger mtrix as the one given in the question in paragraph 1, how can I go about it? Thank you sir/ma'am.

Answer 1

[Nithin Kumar]

Hi Okoth,

I understand that you are trying to convert a multi-dimensional matrix into a column matrix by transposing each row of the multi-dimensional matrix.

You can convert a multi-dimensional matrix into a matrix of required dimensions using "reshape". Kindly refer the following link to know more about the "reshape" function.

https://in.mathworks.com/help/matlab/ref/reshape.html

The following code helps you to generate the required column matrix :

A = randi([1,20],3,3) % generating a 3x3 matrix within the range "1 to 20"

A = 3×3

1 15 20 20 14 8 1 18 18

B = reshape(A.',[],1); % Transposing the matrix "A" row-wise into a Column Matrix
disp(B); % displaying the resultant matrix "B" 

     1
    15
    20
    20
    14
     8
     1
    18
    18

I hope this answer helps you.

Answer 2

[Adithya]

Suppose if matrix A = [1 2 3;4 5 6] , u want a matrix B to be equal to [1 4;2 5;3 6] ie transpose each row to obatain n*1 matrix and then append to B.

U can do this by making use of simple for loop , below is the implementation:

A=[1 2 3; 4 5 6];

n = size(A,1);

B=[];

for i=1:n

C = A(i,:);

B = horzcat(B,C');

end

disp(B);