# How do you initialize an N*M matrix?

866 views (last 30 days)
Harry on 26 Jun 2013
Edited: Arun on 7 Dec 2022
From the MATLAB help, it says to use:
M = matrix(N, M)
but when I apply this it says that the function 'matrix' is not recognized.
Undefined function 'matrix' for input arguments of type 'double'.
Error in experimental (line 1)
M = matrix(3,3)
##### 3 CommentsShow 1 older commentHide 1 older comment
Harry on 27 Jun 2013
Tulike on 12 Jul 2017
M=zeros(N,M)

Leah on 26 Jun 2013
Edited: MathWorks Support Team on 27 Nov 2018
To initialize an N-by-M matrix, use the “zeros” function. For example, create a 3-by-5 matrix of zeros:
A = zeros(3,5);
You can then later assign specific values to the elements of “A”.
##### 3 CommentsShow 1 older commentHide 1 older comment
Abhishek Inamdar on 6 Jul 2021
Use "X = ones(n)" and add the values based on the row and column. Use for loop to work on value addition
israt fatema on 25 Aug 2021
Can you please show me how to assign value to A after initialize the N x M matrix? For example i need to create a vector 5 x 5 and with values x = 20 35 49 64 23

Lokesh Ravindranathan on 26 Jun 2013
Edited: Lokesh Ravindranathan on 26 Jun 2013
I am assuming you are trying to create an empty matrix of zeros of dimensions N*M. You can try the following instead
M = zeros(3,3)
This creates a matrix of zeros of size 3*3.
per isakson on 26 Jun 2013
Edited: per isakson on 26 Jun 2013
matrix is a function in the symbolic toolbox.
Lokesh Ravindranathan on 26 Jun 2013
Oh. Thanks Isakson. I will update my answer. My MATLAB did not have symbolic Math toolbox.

Nitin on 26 Jun 2013
you could initialize the matrix,
M = zeros(n,m);

Pau on 17 Oct 2018
This should make the trick
M = double.empty(N,M,0);
https://uk.mathworks.com/help/matlab/ref/empty.html

Arun on 7 Dec 2022
Edited: Arun on 7 Dec 2022
Here is the documentation for multi dementional arrays in matlab
Here is an example to create and initialize a 3X3 matric
A = [1 2 3; 4 5 6; 7 8 9]
A = 3×3
1 2 3
4 5 6
7 8 9
It is simular to matrix in c programming.

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