tests/testthat/test-mple-target.R

In statnet/ergm: Fit, Simulate and Diagnose Exponential-Family Models for Networks

#  File tests/testthat/test-mple-target.R in package ergm, part of the
#  Statnet suite of packages for network analysis, https://statnet.org .
#
#  This software is distributed under the GPL-3 license.  It is free,
#  open source, and has the attribution requirements (GPL Section 7) at
#  https://statnet.org/attribution .
#
#  Copyright 2003-2023 Statnet Commons
################################################################################
n<-500
base.net <- network.initialize(n=n,directed=FALSE)
norm.stats<-c(.7,.1,.5)
target.stats<-norm.stats*n
print(target.stats)
cat("Structural check:\n")
cat("Mean degree:", norm.stats[1]*2,".\n")
cat("Average degree among nodes with degree 2 or higher:", (2*norm.stats[1]-norm.stats[3])/(1-norm.stats[2]-norm.stats[3]),".\n")

ergm.ts.fit<-ergm(base.net~edges+degree(c(0,1)),target.stats=n*norm.stats,estimate="MPLE")

test_that("internal SAN call achieves the target statistics", {
  expect_equal(summary(ergm.ts.fit$network~edges+degree(c(0,1)),estimate="MPLE"), target.stats, ignore_attr=TRUE)
})

test_that("estimate with target.stats matches that with LHS", {
  ergm.fit<-ergm(ergm.ts.fit$network~edges+degree(c(0,1)),estimate="MPLE")
  expect_equal(coef(ergm.fit),coef(ergm.ts.fit))
})

test_that("simulating from the MPLE target statistics fit", {
  expect_error(ergm.sim<-simulate(ergm.ts.fit,nsim=10,output="stats", control=control.simulate.ergm(MCMC.burnin=10,MCMC.interval=1)), NA)
})

test_that("MPLE with no estimable parameters fails at a later stage", {
  net1<-network.initialize(5578,directed=FALSE)
  expect_error(expect_warning(
    ergm(net1~triangles,target.stats=c(1)),
    "^Model statistics .*triangle.* are not varying..*"),
    "^Number of edges in a simulated network exceeds that in the observed by a factor of more than.*")
})