清空筛选条件
清空筛选条件

Efficient way to identify duplicate edges.

3 次查看（过去 30 天）
Louis
Louis 2013-8-8
评论： TR RAO 2018-1-19
Hello,
I am having trouble coming up with efficient method to identify duplicate edges given the edge list.
Assume we have the following edge list:
SampleEdgeList=[9 8;1 3;4 6;7 3;2 4;3 1;]
First column represent starting nodes and the second column represent corresponding ending nodes. I am working with undirected edges, therefore, second row [1 3] and the sixth row [3 1] means the same thing. As a result, I have duplicate edges connecting node 1 and node 3.
I have EdgeList containing millions of edges, therefore, I would like to avoid for-loops and come up with the most efficient way to identify those duplicate edges.
Ultimately, I would like to regenerate one-end of the nodes for all the duplicate edges, to eliminate all duplicate edges.
Thanks for the help in advance!
Louis

请先登录，再回答此问题。

采纳的回答

the cyclist
the cyclist 2013-8-8
编辑：the cyclist 2013-8-8
uniqueEdgeList = unique(sort(SampleEdgeList,2),'rows')
You can also use the second and third outputs of the unique() function to know which of the original rows map to the unique rows, and vice versa. See
>> doc unique
for details.
  4 个评论
显示 2更早的评论
TR RAO
TR RAO 2018-1-18
fileID = fopen('C:\Users\TR RAO\Desktop\rao1.txt','r'); C = textscan(fileID, '%s %s'); fclose(fileID); d1=cellstr(C{1,1});d2=cellstr(C{1,2}); G=graph(d1,d2); A=adjacency(G) full(A); But this is not working for duplicate edges
Steven Lord
Steven Lord 2018-1-18
TR RAO, see Christine Tobler's comment on Anurag's answer.

请先登录，再进行评论。

更多回答（1 个）

Anurag Passi
Anurag Passi 2016-4-20
I have the same question. However, my edges are in a cell array and are text. For example 'A0A023PXA5' 'O23144' 'A0A023PXP4' 'O23171' 'A0A023PYF7' 'O23171'
and sort (DIM and MODE) do not work on cell arrays. I have also tried to build source and target as separate cell arrays to use
G= graph(s,t)
But i am still getting the same error as:
Error using matlab.internal.graph.MLGraph Duplicate edges not supported.
Error in matlab.internal.graph.constructFromEdgeList (line 125) G = underlyingCtor(double(s), double(t), totalNodes);
Error in matlab.internal.graph.constructFromTable (line 40)
what am I doing wrong.
  2 个评论
Christine Tobler
Christine Tobler 2016-11-2
I realize this is late, but I'll add it in case it's still helpful: sort and unique along the rows are not supported for cell arrays of character vectors (cellstr), but is supported on the new string class. So you can do the following:
edgesString = string([s(:), t(:)]);
edgesUnique = cellstr(unique(edgesString, 'rows'))
g = graph(edgesUnique(:, 1), edgesUnique(:, 2));
It's not very nice-looking, but it should work.
TR RAO
TR RAO 2018-1-19
My data is (1,2) (1, 3) (1,4) (3,1)(2, 1) edgesUnique = cellstr(unique(edgesString, 'rows')) is working. But g = graph(edgesUnique(:, 1), edgesUnique(:, 2)); is not working for thisdata.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Directed Graphs 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by