# Converting a directed graph to undirected
**URL:** https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932
**Category:** Graphs
**Tags:** graphs
**Created:** [August 24, 2021, 6:16pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932 "2021-08-24T18:16:22Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@rachithaiyappa](https://discourse.julialang.org/u/rachithaiyappa)
#### Post date: [August 24, 2021, 6:16pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932/1 "2021-08-24T18:16:22Z")
I am reading a graph from an edge list and then trying to convert the directed graph into undirected as follows.
```nohighlight
using GraphIO
using SimpleGraphs
data = "network.txt" #edge list of the network
g = loadgraph(data,GraphIO.EdgeList.EdgeListFormat())
print(typeof(g)) #prints SimpleDiGraph{Int64}
print(simplify(g)) #should convert SimpleDiGraph to SimpleGraph according to [this documentation](https://github.com/EliasBcd/SimpleGraphs.jl)
```
But I get the following error
```julia
ERROR: LoadError: MethodError: no method matching simplify(::SimpleDiGraph{Int64})
Closest candidates are:
simplify(!Matched::SimpleGraphs.SimpleGraph) at /u/racball/.julia/packages/SimpleGraphs/xiUMi/src/simple_core.jl:388
simplify(!Matched::SimpleDigraph{T}) where T at /u/racball/.julia/packages/SimpleGraphs/xiUMi/src/d_simple_core.jl:284
simplify(!Matched::SimpleHypergraph{T}) where T at /u/racball/.julia/packages/SimpleGraphs/xiUMi/src/hyper/SimpleHypergraphs.jl:50
Stacktrace:
[1] top-level scope at /nfs/nfs9/home/nobackup/racball/github/graphzip/exps/20210824_julia/main.jl:12
[2] include(::Module, ::String) at ./Base.jl:377
[3] exec_options(::Base.JLOptions) at ./client.jl:288
[4] _start() at ./client.jl:484
in expression starting at /nfs/nfs9/home/nobackup/racball/github/graphzip/exps/20210824_julia/main.jl:12
```
Any suggestions?
---
### Author:  [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)
#### Post date: [August 24, 2021, 7:54pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932/2 "2021-08-24T19:54:31Z")
I think `GraphIO` is loading the graph as a `LightGraphs.SimpleDiGraph` rather than a `SimpleGraphs.SimpleDigraph`. In other words, `LightGraphs` is a completely separate graph library that is not compatible with the `SimpleGraphs` library.
Also, the github link in your comment points to a very old fork of `SimpleGraphs.jl`. The correct, up-to-date repository with newer documentation is here:
[https://github.com/scheinerman/SimpleGraphs.jl](https://github.com/scheinerman/SimpleGraphs.jl)
---
### Author:  [@rachithaiyappa](https://discourse.julialang.org/u/rachithaiyappa)
#### Post date: [August 25, 2021, 1:32pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932/3 "2021-08-25T13:32:24Z")
Thank you! I did put a feature request in `GraphIO` to read it as undirected.
---
### Author:  [@etienne\_dg](https://discourse.julialang.org/u/etienne_dg)
#### Post date: [August 25, 2021, 1:41pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932/4 "2021-08-25T13:41:29Z")
You can use `SimpleGraph(g)` to cast to an undirected graph.
---
### Author:  [@rachithaiyappa](https://discourse.julialang.org/u/rachithaiyappa)
#### Post date: [August 31, 2021, 2:16pm UTC](https://discourse.julialang.org/t/converting-a-directed-graph-to-undirected/66932/5 "2021-08-31T14:16:16Z")
Thank you. This works
Just a note for future visitors to this thread -
`G = LightGraphs.SimpleGraph(g)` makes a directed graph `g` into undirected `G`