How to calculate repetition of an unknown number present in 2nd column of a 150*2 matrix?

1 ビュー (過去 30 日間)
Binayak Gouda
Binayak Gouda 2016 年 5 月 20 日
コメント済み: Star Strider 2016 年 5 月 21 日
I've a matrix a=[1,1;2,1;3,1;4,4;5,4] . Actually numbers in the 2nd column are not known in a general case. So, how can i count how many numbers have a particular number (say 1,4) in their corresponding 2nd column.
  1 件のコメント
KSSV
KSSV 2016 年 5 月 20 日
How you can find out with out knowing the numbers?

サインインしてコメントする。

採用された回答

Star Strider
Star Strider 2016 年 5 月 20 日
Use the unique and accumarray functions:
a=[1,1;2,1;3,1;4,4;5,4];
[a2,ia,ic] = unique(a(:,2));
ah = accumarray(ic, 1);
Result = [a2, ah]
Result =
1 3
4 2
So in the second column, there are 3 ‘1’ values and 2 ‘4’ values.
This could be easily changed if you wanted unique row pairs.

その他の回答 (1 件)

Alessandro Masullo
Alessandro Masullo 2016 年 5 月 20 日
You can use the function hist (or histc) on the second column of your matrix.

Community Treasure Hunt

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

Start Hunting!

Translated by