Can I store row numbers of a matrix in a column without using any loop?

2 次查看（过去 30 天）
Nagesh A P
Nagesh A P 2018-6-29
评论： Nagesh A P 2018-6-29
How will I store the first column of a matrix as its corresponding row number without using a loop. That is, the first column for a 3x3 matrix as [1 . .;2 . .;3 . .].
  2 个评论
Nagesh A P
Nagesh A P 2018-6-29
编辑：Nagesh A P 2018-6-29
Ok. This is the case. I have a very large data, something like 100,000 data points, so 100,000 rows. I want to store the first column of a matrix newly created (with as many rows as number of data points mentioned) as its corresponding row number. I can do what you've mentioned. But it'll take me a new matrix and another loop to create that matrix. Could you suggest something which takes less time.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Nithin Banka
Nithin Banka 2018-6-29
a = magic(3);
a(:, 1) = [1:3]; % This will store the row index in the first column of 'a'
  3 个评论
显示 1更早的评论

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 Logical 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