how do you define a matrix and its variable

4 次查看（过去 30 天）
Wenchen Liu
Wenchen Liu 2021-11-15
评论： Adam Danz 2021-11-15
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.

请先登录，再回答此问题。

回答（1 个）

Adam Danz
Adam Danz 2021-11-15
编辑：Adam Danz 2021-11-15
Ran in:
Learn about preallocation.
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
  4 个评论
显示 2更早的评论
Wenchen Liu
Wenchen Liu 2021-11-15
but how could I define i？and should I define it before a and b?

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Matrices and Arrays 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by