# Proportion of unreciprocated ties

**URL:** <https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896>\
**Category:** Usage\
**Tags:** R\
**Created:** [12 October 2021 01:28 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896 "2021-10-12T01:28:07Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![sbr371](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@sbr371](https://igraph.discourse.group/u/sbr371)\
**Post date:** [12 October 2021 01:28 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/1 "2021-10-12T01:28:07Z")

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Hi all,

I’m wondering if there is a function in igraph that will calculate the proportion of ties that are unreciprocated (or reciprocated) for each vertex in the graph.

Thanks!

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**Author:** ![szhorvat](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/szhorvat/32/3_2.png) [@szhorvat](https://igraph.discourse.group/u/szhorvat)\
**Post date:** [12 October 2021 07:25 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/2 "2021-10-12T07:25:53Z")

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Here’s a trick you could use:

Convert the graph to undirected, keeping only reciprocal edges:

```auto
ug <- as.undirected(g, mode = 'mutual')

```

Then `degree(ug) / degree(g, mode = 'out')` will give the fraction of outgoing edges that are reciprocated, for each vertex.

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**Author:** ![tamas](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/tamas/32/1261_2.png) [@tamas](https://igraph.discourse.group/u/tamas)\
**Post date:** [12 October 2021 19:20 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/3 "2021-10-12T19:20:07Z")

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There’s also [reciprocity()](https://igraph.org/r/doc/reciprocity.html).

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<div class="post-metadata">

**Author:** ![szhorvat](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/szhorvat/32/3_2.png) [@szhorvat](https://igraph.discourse.group/u/szhorvat)\
**Post date:** [12 October 2021 20:33 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/4 "2021-10-12T20:33:53Z")

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Indeed, but that gives a single value for the entire graph, while OP wanted a separate value for each vertex.

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<div class="post-metadata">

**Author:** ![tamas](https://yyz2.discourse-cdn.com/free1/user_avatar/igraph.discourse.group/tamas/32/1261_2.png) [@tamas](https://igraph.discourse.group/u/tamas)\
**Post date:** [13 October 2021 09:19 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/5 "2021-10-13T09:19:54Z")

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Ah, sorry, I missed that!

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**Author:** ![sbr371](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@sbr371](https://igraph.discourse.group/u/sbr371)\
**Post date:** [14 October 2021 23:09 UTC](https://igraph.discourse.group/t/proportion-of-unreciprocated-ties/896/6 "2021-10-14T23:09:33Z")

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Thank you @szhorvat, very much appreciated!!!