Summing values for duplicate rows and columns
显示 更早的评论
I have a vector of rows, columns, and values that I will use to create a sparse matrix:
rows = [1 2 3 1]; columns = [1 1 2 1]; values = [10 50 25 90];
Notice the duplicates:
(1,1) 10 (1,1) 90
What I need is to eliminate (row,column) duplicates by summing the values corresponding to these duplicates for each.
The solution in the current example is:
rows = [1 2 3]; columns = [1 1 2]; values = [100 50 25];
What operation on the three initial vectors reduce them to the solution above?
采纳的回答
Andrei Bobrov
2017-7-10
编辑：Andrei Bobrov
2017-7-10
A = accumarray([[1 2 3 1]',[1 1 2 1]'],[10 50 25 90]',[],[],[],1);
更多回答（1 个）
Walter Roberson
2017-7-10
sparse(row, columns, values) is defined to do exactly this kind of totals.
If for some reason you need the simplified outputs afterwards, you can
[r, c, v] = find() on the sparse matrix.
2 个评论
Ulrik William Nash
2017-7-10
Walter Roberson
2017-7-10
result = sparse(r, c, s);
[summary_r, summary_c, summary_s] = find(result);
类别
在 帮助中心 和 File Exchange 中查找有关 Matrix Indexing 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 
