how can i select a random number from a column of a matrix? and then how to find the location of that number?

8 次查看（过去 30 天）

显示更早的评论

Rajeev Kant 2018-4-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/391997-how-can-i-select-a-random-number-from-a-column-of-a-matrix-and-then-how-to-find-the-location-of-tha

评论： Guillaume 2018-4-3

I have a matrix (4x3) and I need to select a value from second column and find the corresponding row number.

For example, A = [11 24 31; 18 19 27; 16 21 34; 23 37 33 28]

Could someone help me?

回答（1 个）

Iddo Weiner 2018-4-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/391997-how-can-i-select-a-random-number-from-a-column-of-a-matrix-and-then-how-to-find-the-location-of-tha#answer_312998

在 MATLAB Online 中打开

If you use a random number to index the row you want to extract, you will already have what you need:

A = randi(10,[4,3]);
rand_row = randi(size(A,1)) %get random row
rand_number = A(rand_row,2) %get your rand number form the 2nd column

5 个评论
显示 3更早的评论隐藏 3更早的评论

Rajeev Kant 2018-4-3

Thank you guys.

What I am looking for the output will be any random element from the second column i.e. anyone of 24,19,21 and 37 (please discard 28 of the 4th row, apology for typo mistake)

and then the corresponding row number i.e.

for 24, row = 1

for 19, row = 2 and so on.

Guillaume 2018-4-3

Choosing a random number from the 2nd column and getting the corresponding row is exactly equivalent to choosing a random row and getting the corresponding number in the 2nd column. Iddo showed you how to do the latter, so again you'll have to explain why it didn't work for you.

请先登录，再进行评论。

请先登录，再回答此问题。

类别

MATLAB Language Fundamentals Matrices and Arrays

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

Community Treasure Hunt

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

Start Hunting!

Translated by