Extracting every row from a matrix using a for loop

38 次查看（过去 30 天）
Edward Keavney
Edward Keavney 2021-10-15
评论： Rik 2021-10-15
I'm working with some velocity data and have a matrix 23,999x31.
I'm new to using Matlab, I'm able of extracting one row but would now like to be able to create a for loop that will allow me to extract each of the 23,999 rows in the matrix.
Any help for a Matlab novice would be greatly appreciated!

请先登录，再回答此问题。

回答（1 个）

Rik
Rik 2021-10-15
This might not be optimal, depending on what you want to do, but the size function is here to help:
data=rand(23999,31)
for row=1:size(data,1)
rowdata=data(row,:);
%do something with that row here
end
  4 个评论
显示 2更早的评论
Edward Keavney
Edward Keavney 2021-10-15
Understood, thanks. I've been approaching the problem in the wrong way. I want to be able to determine the mean from each of the 23,999 rows. Can you help with this?
Rik
Rik 2021-10-15
Ran in:
You can do that with the code I already posted:
data=(1:5).'+rand(5,2);% row x will have values x.####
for row=1:size(data,1)
rowdata=data(row,:);
mean(rowdata) %you can store this in a vector
end
ans = 1.1014
ans = 2.4187
ans = 3.5720
ans = 4.6323
ans = 5.6558
But it is better to use mean on the entire array:
mean(data,2) % specify the dimension to make it operate on the rows
ans = 5×1
1.1014 2.4187 3.5720 4.6323 5.6558

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

产品


版本

R2019a

Community Treasure Hunt

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

Start Hunting!

Translated by