[Rsiena-help] Effects of covariate similarity on the evolution of a bipartite graph?

[Tom Snijders]

Dear Matteo,

>From your first post and your second affiliation I guess that you are well-experienced in programming, and evidently you are welcome to modify RSiena to include this effect for two-mode networks. If later on you want some confirmation of what you've done I shall be happy to look at it.

Best wishes,
Tom

================================================================
Tom A.B. Snijders
Professor of Statistics in the Social Sciences
Department of Politics and Department of Statistics
Nuffield College
University of Oxford
tel. +44-01865-278599


-----Original Message-----
From: Matteo Gagliolo [mailto:mgagliol at ulb.ac.be]
Sent: 08 October 2012 18:19
To: rsiena-help at lists.r-forge.r-project.org
Cc: Tom Snijders
Subject: Re: [Rsiena-help] Effects of covariate similarity on the evolution of a bipartite graph?

Dear Tom,

       I really need this effect in my research, so I'll see what I can do and keep you posted. Help from other users is obviously more than welcome!

Best regards,

Matteo

On Monday 08 October 2012 17:04:06 you wrote:
> Dear Matteo,
>
> That is an interesting topic. For the moment this effect has been
> blacklisted only because this distance-2 effect still needs to be
> checked once more (also in its one-mode version) and because the
> filtering of effects to allow them in the 2-mode version still is
> incomplete. You are right that it should be allowed in. If you (or
> anyone) wishes to contribute and speed this up, then the first thing
> would be to check that the target statistics for this effect in its
> one-mode version as reported in the output are identical to what one
> should expect from the definition of the effect in the manual. This
> will be the first thing I would want to do as a first step to
> incorporate this effect in the two-mode version. Best wishes, Tom
>
> ================================================================
> Tom A.B. Snijders
> Professor of Statistics in the Social Sciences Department of Politics
> and Department of Statistics Nuffield College University of Oxford
> tel. +44-01865-278599
>
>
> -----Original Message-----
> From: rsiena-help-bounces at lists.r-forge.r-project.org
> [mailto:rsiena-help-bounces at lists.r-forge.r-project.org] On Behalf Of
> Matteo Gagliolo Sent: 08 October 2012 15:33
> To: rsiena-help at lists.r-forge.r-project.org
> Subject: [Rsiena-help] Effects of covariate similarity on the
> evolution of a bipartite graph?
>
> Dear RSiena users,
>
>         I'm trying to analyze a two-mode network representing
> interlocking directorates. I have covariates for the mode
> corresponding to boards, and I would like to see if there is a
> tendency of directors to join boards with similar covariates (or
> equivalently, a tendency of boards to form interlocks with similar boards). Sort of an homophily at distance 2.
>
> Taking the boards as mode one, I think this effect could be
> implemented as an interaction among egoX and altDist2, as the latter
> would represent the average X of boards on which a certain director is already sitting.
>
> Here comes my problem: altDist2 is currently "blacklisted" in the code
> for bipartite nets. Diving into the code (RSienaTest r. 220) I found
> out where it all happens: in file effects.r:773, function
> covarBipartiteEff (comments are mine, to explain the issue): ---
> covarBipartiteEff<- function(covarname, poszvar, moreThan2, nodesetNbr,
>                                  name)
>     {
>         covRateEffects  <-  NULL
>         if (nodesetNbr == 1)
>         {#This is the branch taken as the covariate is on the 1st
> mode(boards) covObjEffects <-
>                 createEffects("covarBipartiteObjective", covarname,
>                               name=varname,
>                               groupName=groupName, group=group,
>                               netType=netType) #This returns "altX"
> "altSqX" "egoX"    "altDist2" "simDist2", each replicated as
> eval/creat/endow covObjEffects <-
>                 covObjEffects[covObjEffects$shortName %in%
>                               c("egoX"), ] #Here only "egoX" effects
> are selected ---
>
> So, it seems the code is currently allowing only for egoX effects for
> covariates of the 1st mode.
>
> Does anyone have an idea why? As all distance 2 nodes are in the same
> mode, I don't see why altDist2 and simDist2 should be blacklisted.
>
> Or maybe there is a more correct way to implement the "distance 2 homophily"
> I am interested in?
>
> Thanks,
>
> Matteo
>
> --
> Matteo Gagliolo <mgagliol at ulb.ac.be>
> Group for research on Ethnic Relations, Migration and Equality
> (GERME), Institute of Sociology; Machine Learning Group (MLG),
> Computer Science Department. Université Libre de Bruxelles (ULB).
> GERME, ULB, CP 124, 44 av. Jeanne
> 1050 Brussels, Belgium
> Phone +32 2 650 4798, Fax +32 2 650 4659
> http://homepages.ulb.ac.be/~mgagliol/
>
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> Nuffield College is a Registered Charity No. 1137506. Registered Office:
> Nuffield College, New Road, Oxford, OX1 1NF
--
Matteo Gagliolo <mgagliol at ulb.ac.be>
Group for research on Ethnic Relations, Migration and Equality (GERME), Institute of Sociology; Machine Learning Group (MLG), Computer Science Department.
Université Libre de Bruxelles (ULB).
GERME, ULB, CP 124, 44 av. Jeanne
1050 Brussels, Belgium
Phone +32 2 650 4798, Fax +32 2 650 4659 http://homepages.ulb.ac.be/~mgagliol/


Nuffield College is a Registered Charity No. 1137506. Registered Office: Nuffield College, New Road, Oxford, OX1 1NF