How to extract array from the mean directly using indexing?

2 次查看（过去 30 天）
William
William 2023-7-6
编辑： Nikhil Baishkiyar 2023-7-6
A = [2.29441228002842 17.3351873969651 2.79928860040389 7.17554281085515;
3.16200415659481 16.9975006219209 3.18395042061777 7.45747601536461;
4.55387378846938 13.4948344868957 3.22594708715312 7.49001605579868]
meanA = mean(A,1)
output: [3.3368 15.9425 3.0697 7.3743]
how can i get second element of mean in one line?
ex:
mean(A,1)(2)
  • (2) is index
But, it is not working. Thanks.

请先登录，再回答此问题。

采纳的回答

Nikhil Baishkiyar
编辑：Nikhil Baishkiyar 2023-7-6
Ran in:
A = [2.29441228002842 17.3351873969651 2.79928860040389 7.17554281085515;
3.16200415659481 16.9975006219209 3.18395042061777 7.45747601536461;
4.55387378846938 13.4948344868957 3.22594708715312 7.49001605579868]
A = 3×4
2.2944 17.3352 2.7993 7.1755 3.1620 16.9975 3.1840 7.4575 4.5539 13.4948 3.2259 7.4900
mean(A(:,2))
ans = 15.9425
You mean something like this?
subindex = @(matrix, r) matrix(r); % An anonymous function for indexing
value = subindex(mean(A,1), 2) % Use the function to index the vector
value = 15.9425
  3 个评论
显示 1更早的评论
William
William 2023-7-6
编辑：William 2023-7-6
Yeah.. But we only got second column. It seems we will use mean four times. if there is thousands?
Actually, all of data is needed. and indexing is what can solve the problem and can ellimitate the time complexity. or we can use two lines to make the mean variable.
Nikhil Baishkiyar
Nikhil Baishkiyar 2023-7-6
编辑：Nikhil Baishkiyar 2023-7-6
I read the post and updated my answer based on that. If you want every mean value you will have to store it in a temporary variable I am afraid

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Resizing and Reshaping Matrices 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