p2ML: MCMC estimates for the (multilevel) p2 model

p2MLR Documentation

MCMC estimates for the (multilevel) p2 model

Description

Estimates the (multilevel) p2 model parameters,as described in Zijlstra, Van Duijn and Snijders (2006) <doi: 10.1027/1614-2241.2.1.42>.

Usage

p2ML(nets, sender = NULL, receiver = NULL, density =~ 1, reciprocity =~ 1, 
adapt = NULL, burnin = NULL, center = NULL, separate= NULL, seed = NULL) 

Arguments

nets

List with n dichotomous dependent directed networks.

sender

Optional matrix with a stacked actor-level sender covariate, corresponding to the n networks. Multiple sender covariates can be added as a formula object, see example below

receiver

Optional matrix with a stacked actor-level receiver covariate, corresponding to the n networks. Multiple receiver covariates can be added as a formula object

density

Optional stacked matrix with a density covariate, with dimensions similar to the n dependent networks. Multiple density covariates can be added as a formula object, see example below

reciprocity

Optional stacked matrix with a symmetric reciprocity covariate, with dimensions similar to the n dependent networks. Multiple reciprocity covariates can be added as a formula object

adapt

Optional number of adaptive sequenses (default is 125).

burnin

Optional specification of number of burn-in iterations (default is 2500).

center

Optional argument for centering predictors (default is TRUE).

separate

Optional argument for estimating separate coefficients for the n dependent networks (default is FALSE).

seed

Optonal specification of random seed (delfault is 1).

Value

Returns a fitted model of class 2ML, to be opened with the function summary().

Author(s)

Bonne J.H. Zijlstra b.j.h.zijlstra@uva.nl

References

Zijlstra, B. J., Van Duijn, M. A., & Snijders, T. A. (2006). The Multilevel p2 Model A random effects model for the analysis of multiple social networks. Methodology: European Journal of Research Methods for the Behavioral and Social Sciences, 2(1), 42.

Examples


# create two very small networks with covariates for illustrative purposes
Y1 <- matrix(c(0,1,0,1,0,1,0,1,0,0,
               0,0,1,1,0,1,0,1,0,1,
               1,1,0,0,1,0,0,0,0,0,
               1,1,1,0,1,0,0,0,0,1,
               1,0,1,0,0,1,1,0,1,1,
               0,0,0,0,0,0,1,1,1,1,
               0,0,0,0,0,1,0,1,0,1,
               1,0,0,0,0,1,1,0,1,1,
               0,1,0,1,0,1,0,1,0,0,
               0,0,1,1,1,0,0,0,0,0), ncol=10)
Y2 <- matrix(c(0,0,1,0,1,0,0,1,0,0,
               0,0,0,0,0,0,0,1,1,0,
               0,0,0,1,0,1,0,1,0,1,
               0,0,1,0,0,0,1,1,0,0,
               1,0,0,1,0,0,1,0,0,1,
               0,0,1,0,0,0,1,1,0,0,
               0,1,0,0,1,0,0,0,0,0,
               1,0,1,0,1,1,1,0,0,1,
               0,1,0,1,0,0,0,0,0,0,
               0,1,0,1,0,0,0,1,0,0), ncol=10) 
Y <- list(Y1, Y2)                
Sa1 <- c(1,0,1,0,1,1,0,1,0,1)
Sa2 <- c(1,0,0,1,0,0,1,1,0,1)
Sa <- list(Sa1, Sa2)
Sat <- Rat <-  do.call(plyr::rbind.fill.matrix, Sa)
Sb1 <- c(0,1,1,0,1,0,1,0,1,0)
Sb2 <- c(1,0,1,0,0,1,0,1,0,1)
Sb <- list(Sb1, Sb2)
Sbt <- do.call(plyr::rbind.fill.matrix, Sb)
Da1 <- abs(matrix(rep(Sa1,10), byrow = FALSE, ncol= 10) -
              matrix(rep(Sa1,10), byrow = TRUE, ncol= 10))
Da2 <- abs(matrix(rep(Sa2,10), byrow = FALSE, ncol= 10) -
              matrix(rep(Sa2,10), byrow = TRUE, ncol= 10))
Da <- list(Da1, Da2)
Dat <- do.call(plyr::rbind.fill.matrix, Da)

# estimate p2 model for two networks
M1 <- p2ML(Y, sender= ~ Sat + Sbt,  receiver= ~ Rat, density = ~ Dat, adapt = 10, burnin = 100)
summary(M1)
# Notice: burn-in, and number of adaptive sequenses are 
# much smaller than recommended to keep computation time low.
# recommended code: 
## Not run: 
M1 <- p2ML(Y,sender= ~ Sat + Sbt,  receiver= ~ Rat, density = ~ Dat)
summary(M1)

## End(Not run)

# estimate p2 model for a single network
M2 <- p2ML(list(Y[[1]]),sender= ~ Sat[1:10,] + Sbt[1:10,],  receiver= ~ Rat[1:10,],
density = ~ Dat[1:10,], adapt = 10, burnin = 100)
summary(M2)
# Notice: burn-in, and number of adaptive sequenses are 
# much smaller than recommended to keep computation time low.
# recommended code: 
## Not run: 
M2 <- p2ML(list(Y[[1]]),sender= ~ Sat[1:10,] + Sbt[1:10,],  receiver= ~ Rat[1:10,], 
density = ~ Dat[1:10,])
summary(M2)

## End(Not run)

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