Count number of rows that meet criteria based on elements in other rows

17 次查看（过去 30 天）
Neuro
Neuro 2022-3-31
回答： Voss 2022-3-31
Hello. How can one count the number of rows based on the elements in the columns? For example, if we have the following matrix:
3 0 0 2
5 0 0 2
2 0 1 2
2 0 1 2
1 1 1 3
4 1 0 2
3 1 1 2
1 1 1 3
5 1 0 1
4 1 1 1
How can we count the number of rows that have number 2 in the first column and number 1 in the third column? I guess one should use 'length' right? Thanks!

请先登录，再回答此问题。

回答（1 个）

Voss
Voss 2022-3-31
nnz(A(:,1) == 2 & A(:,3) == 1)
% 1st column is 2 & 3rd column is 1
where A is your matrix

类别

在 Help Center 和 File Exchange 中查找有关 Operating on Diagonal Matrices 的更多信息

标签

产品


版本

R2021b

Community Treasure Hunt

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

Start Hunting!

Translated by