Divide each column by the sum of the column in a matrix

9 次查看(过去 30 天)
I am sure this is an elementary question, but I could not find the answer when searching the Matlab website. I was wondering how to divide each column in a matrix by the sum of that column and do the same process for all the columns in a matrix. The result should then be returned as a new matrix.
As an example take the following matrix
D = [-0.442898926677253 -0.165258150390309 0.850111606631490 -0.801783725737275;
-0.505610279127129 0.455832504673115 -0.205467096352270 4.76435784320108e-15;
-0.540885414880185 -0.746406858955920 -0.439177413926944 0.534522483824847;
-0.505610279127129 0.455832504673115 -0.205467096352275 0.267261241912423];
Now, for the first column;
U(:,1)/sum(U(:,1))
gets the first column of D divided by the sum of the column, but how do I do this for all of the columns and return the output as a new matrix?
  2 个评论
Matt J
Matt J 2022-5-19
U(:,1)/sum(U(:,1)) gets the first column of D divided by the sum of the column
No, it does that for U, not D.

请先登录,再进行评论。

采纳的回答

Matt J
Matt J 2022-5-19
  6 个评论
Torsten
Torsten 2022-5-19
Just display D and look at the respective columns. You should be able to find the reason by inspection.
Matt J
Matt J 2022-5-19
编辑:Matt J 2022-5-20
Wonder what could cause it to return as 'not a number'?
That would happen if the column sum is zero, and the column also contains some zeros, e.g.,
D=[-1;0;1];
D/sum(D)
ans = 3×1
-Inf NaN Inf

请先登录,再进行评论。

更多回答(0 个)

类别

Help CenterFile Exchange 中查找有关 Matrix Indexing 的更多信息

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