# how do you define a matrix and its variable

3 views (last 30 days)
Wenchen Liu on 15 Nov 2021
Commented: Adam Danz on 15 Nov 2021
I want to create a matrix , by i * j, in matlab, and then let matlab run this. I need to tell matlab what is i and what is j before i define the matrix, right? Then when I define the matrix, can I write aMatrix = [i, j]?
I know how to do matrix like: aMatrix = [1 3 7 ; 5 6 7], but now I want to know how to make a general matrix by giving i and j in matlab.

Adam Danz on 15 Nov 2021
Edited: Adam Danz on 15 Nov 2021
Options:
i = 4;
j = 3;
M = nan(i,j)
M = 4×3
NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN
M = ones(i,j)
M = 4×3
1 1 1 1 1 1 1 1 1 1 1 1
M = zeros(i,j)
M = 4×3
0 0 0 0 0 0 0 0 0 0 0 0
Adam Danz on 15 Nov 2021
Yes, just like in my demo.

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