Nothing
tests/testthat/test-mcem.R
In nimble: MCMC, Particle Filtering, and Programmable Hierarchical Modeling
source(system.file(file.path('tests', 'testthat', 'test_utils.R'), package = 'nimble'))
RwarnLevel <- options('warn')$warn
options(warn = 1)
RdigitsOption <- options('digits')$digits
options(digits = 6)
nimbleVerboseSetting <- nimbleOptions('verbose')
nimbleOptions(verbose = TRUE)
nimbleProgressBarSetting <- nimbleOptions('MCMCprogressBar')
nimbleOptions(MCMCprogressBar = FALSE)
context("Testing of MCEM")
goldFileName <- 'mcemTestLog_Correct.Rout'
tempFileName <- 'mcemTestLog.Rout'
generatingGoldFile <- !is.null(nimbleOptions('generateGoldFileForMCEMtesting'))
outputFile <- if(generatingGoldFile) file.path(nimbleOptions('generateGoldFileForMCEMtesting'), goldFileName) else tempFileName
sink_with_messages(outputFile)
# Set up numerically precise MLE and vcov results
# for both regular and transformed coordinates
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:10) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pump_optim_trans <- optim(log(c(.75, 1.5)), pump_llh,
method = "BFGS", control = list(fnscale = -1),
hessian=TRUE, trans = TRUE)
pump_mle_trans <- pump_optim_trans$par
pump_vcov_trans <- inverse(-pump_optim_trans$hessian)
test_that("MCEM error-trapping", {
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta);
lambda[i] <- theta[i]*t[i];
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0);
beta ~ dgamma(0.1,1.0);
})
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pumpModel <- nimbleModel(code = pumpCode, constants = pumpConsts,
data = pumpData, inits = pumpInits,
buildDerivs=TRUE)
# Catch old syntax usage (for nimble < 1.2.0)
expect_error(pumpMCEM <- buildMCEM(model = pumpModel, burnIn=200))
# Correct message when boxConstraints will be ignored
expect_message(pumpMCEM <- buildMCEM(model = pumpModel,
control=list(boxConstraints = list(a = 1))),
"boxConstraints will be ignored")
# Catch when node setup is fully provided by some latent nodes don't exist.
defaultMargNodes <- setupMargNodes(pumpModel)
defaultMargNodes$randomEffectsNodes <- c(defaultMargNodes$randomEffectsNodes, "junk")
expect_error(pumpMCEM <- buildMCEM(model = pumpModel, paramNodes=defaultMargNodes))
})
test_that("MCEM pump with all defaults (roxygen example)", {
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta);
lambda[i] <- theta[i]*t[i];
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0);
beta ~ dgamma(0.1,1.0);
})
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pumpModel <- nimbleModel(code = pumpCode, constants = pumpConsts,
data = pumpData, inits = pumpInits,
buildDerivs=TRUE)
pumpMCEM <- buildMCEM(model = pumpModel)
CpumpModel <- compileNimble(pumpModel)
CpumpMCEM <- compileNimble(pumpMCEM, project=pumpModel)
set.seed(1)
MLE <- CpumpMCEM$findMLE()
vcov <- CpumpMCEM$vcov(MLE$par)
expect_equal(MLE$par, pump_mle, tol = 0.03)
expect_equal(vcov, pump_vcov, tol = 0.03)
samples <- as.matrix(CpumpMCEM$mvSamples)
expect_equal(ncol(samples), 10)
expect_true(nrow(samples)>=1000)
})
test_that("MCEM with pump transform=FALSE",{
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
# Although using the transformation or not is baked into the optimization
# the vcov procedure allows to return with or without it.
# In this case, there should be no difference since there is no
# transormation in use.
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans = TRUE)
expect_identical(vct, vc)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 500, maxM = 500, burnin = 100, maxIter = 1)
expect_false(abs(out$par[2] - pump_mle[2]) < .02)
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000,
burnin = 300, maxIter = 20, continue = TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check on the continue=TRUE feature and see if
# we get to convergence going one by one from the outside
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, burnin = 300,
Mfactor = 0.5, maxIter = 1)
for(i in 1:4)
out <- cpumpMCEM$findMLE(continue = TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
# Next check that it will run with ascent=FALSE
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, burnin = 300,
Mfactor = 0.5, ascent=FALSE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check that it will run with ascent=TRUE but
# meaningful limit set by maxM
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 2000, burnin = 300,
Mfactor = 0.5, ascent=TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check that it will run with minIter=2
# and also with C = 3 (converge at least three times)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 2000, burnin = 300,
Mfactor = 0.5, ascent=TRUE, minIter = 2,
C = 3)
expect_equal(out$par, pump_mle, tol = 0.03)
})
test_that("MCEM pump with transform=TRUE", {
# transformed version: Use parameter transformation
## build an MCEM algorithm with Ascent-based convergence criterion
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(burnin = 300,
mcmcControl = list(adaptInterval = 100),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform = TRUE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
## tol changed from .001 to .01 to make the test run faster
## Correspondingly expect_equal tolerance
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans=TRUE)
expect_equal(vct, pump_vcov_trans, tol=0.03)
# Now check when we request parameters returned on the transformed
# scale
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, returnTrans=TRUE)
expect_equal(out$par, pump_mle_trans, tol=0.01)
vc <- cpumpMCEM$vcov(out$par, trans = TRUE)
expect_equal(vc, pump_vcov_trans, tol=0.02)
vct <- cpumpMCEM$vcov(out$par, trans = TRUE, returnTrans=FALSE)
expect_equal(vct, pump_vcov, tol=0.03)
})
test_that("MCEM pump without AD, with transform=FALSE", {
####
# version without AD
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(useDerivs=FALSE,
burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=FALSE, resetSamples = TRUE, M = 10000)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans=FALSE, returnTrans = TRUE)
expect_identical(vc, vct)
})
test_that("MCEM pump without AD, with transform=TRUE", {
####
# version without AD
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(useDerivs=FALSE,
burnIn = 300,
mcmcControl = list(adaptInterval = 100),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=TRUE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans=TRUE)
expect_equal(vct, pump_vcov_trans, tol=0.03)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, returnTrans = TRUE)
vc <- cpumpMCEM$vcov(out$par, trans=TRUE)
expect_equal(vc, pump_vcov_trans, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=TRUE, returnTrans=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
## Test of case where some parts of the model
## are not related to missing data or latent states
test_that("MCEM with pump transform=FALSE and some calcNodesOther",{
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22),
theta = c(rep(NA, 8), .8, 1.2))
pumpInits <- list(alpha = 1, beta = 1,
theta = c(rep(0.1, pumpConsts$N-2), NA, NA))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:8) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
for(i in 9:10) {
llh <- llh + dgamma(pumpData$theta[i], shape = alpha, rate = beta, log=TRUE)
llh <- llh + dpois(pumpData$x[i], pumpData$theta[i], log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta[1:8]',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
expect_equal(length(pumpMCEM$E$calcNodesOther), 3)
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, C = 2)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE, atMLE=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
test_that("MCEM with pump transform=FALSE and some calcNodesOther, noAD",{
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22),
theta = c(rep(NA, 8), .8, 1.2))
pumpInits <- list(alpha = 1, beta = 1,
theta = c(rep(0.1, pumpConsts$N-2), NA, NA))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:8) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
for(i in 9:10) {
llh <- llh + dgamma(pumpData$theta[i], shape = alpha, rate = beta, log=TRUE)
llh <- llh + dpois(pumpData$x[i], pumpData$theta[i], log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = FALSE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta[1:8]',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE,
useDerivs=FALSE))
expect_equal(length(pumpMCEM$E$calcNodesOther), 3)
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, C = 2)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE, atMLE=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
#######
# Adopting some (far from all) tests from test-ADlaplace
test_that("MCEM simplest 1D works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(a, sd = 2)
a ~ dnorm(mu, sd = 3)
mu ~ dnorm(0, sd = 5)
}), data = list(y = 4), inits = list(a = -1, mu = 0),
buildDerivs = TRUE
)
mMCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(mMCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE()
expect_equal(opt$par, 4, tol = .01)
vc <- cMCEM$vcov(opt$par)
# See test-ADlaplace for derivation
expect_equal(vc[1,1], 13, tol = .02)
})
test_that("MCEM simplest 1D with a constrained parameter works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(a, sd = 2)
a ~ dnorm(mu, sd = 3)
mu ~ dexp(1.0)
# I am not sure why Laplace works if init mu is 0 (log(0)=-Inf)
# but this doesn't. Both use BFGS.
}), data = list(y = 4), inits = list(a = -1, mu = 0.5),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE(C = 2)
vc <- cMCEM$vcov(opt$par)
# V[a] = 9
# V[y] = 9 + 4 = 13
# Cov[a, y] = V[a] = 9 (not needed)
# y ~ N(mu, 13)
# muhat = y = 4
# ahat = (9*y+4*mu)/(9+4) = y = 4
# Jacobian of ahat wrt transformed param log(mu) is 4/13*mu = 4*mu/13 = 16/13
# Hessian of joint loglik wrt a: -(1/4 + 1/9)
# Hessian of marginal loglik wrt transformed param log(mu) is (y*mu - 2*mu*mu)/13 = -4^2/13
# Variance of transformed param is 13/16
expect_equal(opt$par, 4, tol = 0.01)
# Covariance matrix (of mu and a) on transformed scale
vcov_transform <- matrix(c(0, 0, 0, 1/(1/4+1/9)), nrow = 2) + matrix(c(1, 16/13), ncol = 1) %*% (13/16) %*% t(matrix(c(1, 16/13), ncol = 1))
# Covariance matrix on original scale
vcov <- diag(c(4, 1)) %*% vcov_transform %*% diag(c(4, 1))
expect_equal(vcov[1,1], vc[1,1], tol = 0.1)
vct <- cMCEM$vcov(opt$par, returnTrans=TRUE)
expect_equal(vcov_transform[1,1], vct[1,1], tol = 0.03)
# Get results on transformed scale
set.seed(0)
cm$mu <- 0.5
opt <- cMCEM$findMLE(C = 2, returnTrans = TRUE)
expect_equal(opt$par, log(4), tol = 0.01)
vc <- cMCEM$vcov(opt$par, trans = TRUE, returnTrans = FALSE)
expect_equal(vcov[1,1], vc[1,1], tol = 0.1)
vct <- cMCEM$vcov(opt$par, trans = TRUE, returnTrans = TRUE)
expect_equal(vcov_transform[1,1], vct[1,1], tol = 0.03)
})
# Skipping " simplest 1D (constrained) with multiple data"
# The main difference there should be simply model structure
# that we don't need to test here.
test_that("MCEM simplest 1D with deterministic intermediates and multiple data works", {
set.seed(1)
m <- nimbleModel(
nimbleCode({
mu ~ dnorm(0, sd = 5)
a ~ dexp(rate = exp(0.5 * mu))
for (i in 1:5){
y[i] ~ dnorm(0.2 * a, sd = 2)
}
}), data = list(y = rnorm(5, 1, 2)), inits = list(mu = 2, a = 1),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
cm$mu <- 2
opt <- cMCEM$findMLE(C = 2)
vc <- cMCEM$vcov(opt$par)
# Results are checked using those from TMB
# See test-ADlaplace for checking results from TMB
# However, for this little toy, we get a slightly different estimate
# and so we check it with grid-based integration of the llh
#
#
## true_llh <- function(mu) {
## lambda <- exp(0.5 * mu)
## a_max <- qexp(0.9999, lambda)
## a_grid <- seq(0, a_max, length = 1000)
## delta_a <- diff(a_grid[1:2])
## a_grid <- a_grid[-1]-delta_a/2
## lh <- 0
## y <- cm$y
## for(i in 1:999) {
## llh_given_a <- dnorm(y, mean = 0.2*a_grid[i], sd = 2, log=TRUE) |>
## sum()
## lh <- lh + exp(llh_given_a) * dexp(a_grid[i], lambda)*delta_a
## }
## llh <- log(lh)
## llh
## }
## true_ans <- optimize(true_llh, lower=-4, upper=4, maximum=TRUE)
## true_mle <- true_ans$maximum # -2.856
## true_hess <- nimDerivs(true_llh(true_mle))
## true_var <- 1/(-true_hess$hessian[1,1,1]) # 8.150
## true_sd <- sqrt(true_var)
expect_equal(opt$par, -2.856, .04)
expect_equal(vc[1,1], 8.150, 0.1)
# Check covariance matrix for params only
})
# Case "1D with deterministic intermediates works" from Laplace seems redundant
test_that("MCEM 1D with a constrained parameter and deterministic intermediates works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(0.2 * a, sd = 2)
a ~ dnorm(0.5 * mu, sd = 3)
mu ~ dexp(1.0)
}), data = list(y = 4), inits = list(a = -1, mu = 0.5),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE(tol = 0.0001)
vc <- cMCEM$vcov(opt$par)
# Correct answer first by direct integration and
# next by theory
## true_llh <- function(mu) {
## mean_a <- 0.5 * mu
## a_min <- qnorm(0.00001, mean = mean_a, sd = 3)
## a_max <- qnorm(0.99999, mean = mean_a, sd = 3)
## a_grid <- seq(a_min, a_max, length = 1000)
## delta_a <- diff(a_grid[1:2])
## a_grid <- a_grid[-1]-delta_a/2
## lh <- 0
## y <- cm$y
## for(i in 1:999) {
## llh_given_a <- dnorm(y, mean = 0.2*a_grid[i], sd = 2, log=TRUE) |>
## sum()
## lh <- lh + exp(llh_given_a) * dnorm(a_grid[i], mean_a, sd=3)*delta_a
## }
## llh <- log(lh)
## llh
## }
## true_ans <- optimize(true_llh, lower=20, upper=60, maximum=TRUE)
## true_mle <- true_ans$maximum # 40
## true_hess <- nimDerivs(true_llh(true_mle))
## true_var <- 1/(-true_hess$hessian[1,1,1]) # 436.007
## true_sd <- sqrt(true_var)
# And by theory
# V[a] = 9
# V[y] = 0.2^2 * 9 + 4 = 4.36
# y ~ N(0.2*0.5*mu, 4.36)
# muhat = y/(0.2*0.5) = 40
# ahat = (9*0.2*y + 4*0.5*mu)/(4+9*0.2^2) = 20
# Jacobian of ahat wrt transformed param log(mu) is 4*0.5*mu/(4+9*0.2^2) = 18.34862
# Hessian of joint loglik wrt a: -(0.2^2/4 + 1/9)
# Hessian of marginal loglik wrt param mu is -(0.2*0.5)^2/4.36
# Hessian of marginal loglik wrt transformed param log(mu) is (0.2*0.5*y*mu - 2*0.1^2*mu*mu)/4.36 = -3.669725
vcov_transform <- matrix(c(0, 0, 0, 1/(0.2^2/4+1/9)), nrow = 2) + matrix(c(1, 18.34862), ncol = 1) %*% (1/3.669725) %*% t(matrix(c(1, 18.34862), ncol = 1))
# Covariance matrix on original scale
vcov <- diag(c(40,1)) %*% vcov_transform %*% diag(c(40,1))
expect_equal(opt$par, 40, tol = 1)
expect_equal(vc[1,1], vcov[1,1], tol = 50) # out of 436
cm$mu <- 0.5
opt <- cMCEM$findMLE(tol = 0.0001, returnTrans = TRUE)
expect_equal(opt$par, log(40), tol = 0.02)
vc <- cMCEM$vcov(opt$par, trans=TRUE, returnTrans = TRUE, M = 50000)
expect_equal(vc[1,1], vcov_transform[1,1], tol = 0.1) #
})
# Skipping "with deterministic intermediates and multiple data works"
test_that("MCEM simplest 2x1D works, with multiple data for each", {
set.seed(1)
y <- matrix(rnorm(6, 4, 5), nrow = 2)
m <- nimbleModel(
nimbleCode({
for(i in 1:2) {
mu_y[i] <- 0.8*a[i]
for(j in 1:3)
y[i, j] ~ dnorm(mu_y[i], sd = 2)
a[i] ~ dnorm(mu_a, sd = 3)
}
mu_a <- 0.5 * mu
mu ~ dnorm(0, sd = 5)
}), data = list(y = y), inits = list(a = c(-2, -1), mu = 0),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE()
expect_equal(opt$par, mean(y)/(0.8*0.5), tol = 0.04) # optim's reltol is about 1e-8 but that is for the value, not param.
vc <- cMCEM$vcov(opt$par)
## # V[a] = 9
## # V[y[i]] = 0.8^2 * 9 + 4 = 9.76
## # Cov[a, y[i]] = 0.8 * 9 = 7.2
## # Cov[y[i], y[j]] = 0.8^2 * 9 = 5.76, within a group
## Cov_A_Y <- matrix(nrow = 8, ncol = 8)
## Cov_A_Y[1, 1:8] <- c( 9, 0, 7.2, 7.2, 7.2, 0, 0, 0)
## Cov_A_Y[2, 1:8] <- c( 0, 9, 0, 0, 0, 7.2, 7.2, 7.2)
## Cov_A_Y[3, 1:8] <- c(7.2, 0, 9.76, 5.76, 5.76, 0, 0, 0)
## Cov_A_Y[4, 1:8] <- c(7.2, 0, 5.76, 9.76, 5.76, 0, 0, 0)
## Cov_A_Y[5, 1:8] <- c(7.2, 0, 5.76, 5.76, 9.76, 0, 0, 0)
## Cov_A_Y[6, 1:8] <- c( 0, 7.2, 0, 0, 0, 9.76, 5.76, 5.76)
## Cov_A_Y[7, 1:8] <- c( 0, 7.2, 0, 0, 0, 5.76, 9.76, 5.76)
## Cov_A_Y[8, 1:8] <- c( 0, 7.2, 0, 0, 0, 5.76, 5.76, 9.76)
## Cov_Y <- Cov_A_Y[3:8, 3:8]
## chol_cov <- chol(Cov_Y)
## res <- dmnorm_chol(as.numeric(t(y)), mean(y), cholesky = chol_cov, prec_param=FALSE, log = TRUE)
## expect_equal(opt$value, res)
## # muhat = mean(y)/(0.8*0.5)
## # ahat[1] = (9*0.8*sum(y[1,]) + 4*0.5*mu)/(4+9*0.8^2*3)
## # ahat[2] = (9*0.8*sum(y[2,]) + 4*0.5*mu)/(4+9*0.8^2*3)
## # Jacobian of ahat[i] wrt mu is 4*0.5/(4+9*0.8^2*3) = 0.09398496
## # Hessian of joint loglik wrt a[i]a[i]: -(3*0.8^2/4 + 1/9); wrt a[i]a[j]: 0
## # Hessian of marginal loglik wrt mu: -0.04511278 (numerical, have not got AD work)
muhat <- mean(y)/(0.8*0.5)
# Covariance matrix
vcov <- diag(c(0, rep(1/(3*0.8^2/4 + 1/9), 2))) + matrix(c(1, rep(0.09398496, 2)), ncol = 1) %*% (1/0.04511278) %*% t(matrix(c(1, rep(0.09398496, 2)), ncol = 1))
expect_equal(vcov[1,1], vc[1,1], tol = 0.02)
## Check covariance matrix for params only
})
#skipping " with 2x1D random effects needing joint integration works, without intermediate nodes"
# and "Laplace with 2x1D random effects needing joint integration works, with intermediate nodes"
# This case would need more attention
# The MCEM convergence path is painfully slow.
# It might be better with a reparameterization.
# But for now it is thought that this test is not really needed
# for any specific functionality.
## test_that("MCEM with 2x2D random effects for 1D data that are separable works, with intermediate nodes", {
## # This example gives a really bad MCEM convergence path
## set.seed(1)
## # y[i, j] is jth datum from ith group
## y <- array(rnorm(8, 6, 5), dim = c(2, 2, 2))
## cov_a <- matrix(c(2, 1.5, 1.5, 2), nrow = 2)
## m <- nimbleModel(
## nimbleCode({
## for(i in 1:2) mu[i] ~ dnorm(0, sd = 10)
## mu_a[1] <- 0.8 * mu[1]
## mu_a[2] <- 0.2 * mu[2]
## for(i in 1:2) a[i, 1:2] ~ dmnorm(mu_a[1:2], cov = cov_a[1:2, 1:2])
## for(i in 1:2) {
## for(j in 1:2) {
## y[1, j, i] ~ dnorm( 0.5 * a[i, 1], sd = 1.8) # this ordering makes it easier below
## y[2, j, i] ~ dnorm( 0.1 * a[i, 2], sd = 1.2)
## }
## }
## }),
## data = list(y = y),
## inits = list(a = matrix(c(-2, -3, 0, -1), nrow = 2), mu = c(0, .5)),
## constants = list(cov_a = cov_a),
## buildDerivs = TRUE
## )
## MCEM <- buildMCEM(model = m)
## cm <- compileNimble(m)
## cMCEM <- compileNimble(MCEM, project = m)
## Laplace <- buildLaplace(m)
## cLaplace <- compileNimble(Laplace, project = m)
## MLE <- cLaplace$findMLE()
## cLaplace$calcLogLik(c(12.9840, 405.9512))
## cLaplace$calcLogLik(c(12.2434, 391.044))
## # this takes a long time. the convergence path is poor.
## set.seed(0)
## cm$mu <- c(0, 0.5)
## opt <- cMCEM$findMLE(alpha = 0.1, maxIter = 300, maxM = 50000)
## })
test_that("MCMC for simple LME case works", {
set.seed(1)
g <- rep(1:10, each = 5)
n <- length(g)
x <- runif(n)
mc <- nimbleCode({
for(i in 1:n) {
y[i] ~ dnorm((random_int[g[i]]) +
(random_slope[g[i]])*x[i], sd = sigma_res)
}
for(i in 1:ng) {
random_int[i] ~ dnorm(fixed_int , sd = sigma_int)
random_slope[i] ~ dnorm(fixed_slope, sd = sigma_slope)
}
sigma_int ~ dhalfflat() #dunif(0, 10)
sigma_slope ~ dhalfflat() #dunif(0, 10)
sigma_res ~ dhalfflat() #dunif(0, 10)
fixed_int ~ dnorm(0, sd = 100)
fixed_slope ~ dnorm(0, sd = 100)
})
m <- nimbleModel( mc,
constants = list(g = g, ng = max(g), n = n, x = x),
buildDerivs = TRUE
)
params <- c("fixed_int", "fixed_slope", "sigma_int", "sigma_slope", "sigma_res")
values(m, params) <- c(10, 0.5, 3, .25, 0.2)
m$simulate(m$getDependencies(params, downstream = TRUE, self = FALSE))
m$setData('y')
y <- m$y
cm <- compileNimble(m)
# We can do this by lme4, but instead we'll use nimble's Laplace
#library(lme4)
#manual_fit <- lmer(y ~ x + (1 + x || g), REML = FALSE)
#data <- data.frame(y = y, x = x, g = g)
# The reason to use our Laplace is to compare MLEs in terms of
# the log likelihood itself.
MCEM <- buildMCEM(model = m, latentNodes = c("random_int", "random_slope"),
control = list(
mcmcControl = list(adaptInterval = 20)))
cMCEM <- compileNimble(MCEM, project = m)
set.seed(1)
values(cm, params) <- c(0, 0, 1, 1, 1)
opt <- cMCEM$findMLE(maxIter = 2000, initM = 1000, burnin = 300,
maxM = 50000, tol = 0.001)
m2 <- nimbleModel( mc,
constants = list(g = g, ng = max(g), n = n, x = x),
data = list(y = m$y),
buildDerivs = TRUE
)
for(v in m2$getVarNames()) m2[[v]] <- m[[v]]
m2$calculate()
cm2 <- compileNimble(m2)
Laplace <- buildLaplace(model=m2, randomEffectsNodes = c("random_int", "random_slope"))
cLaplace <- compileNimble(Laplace, project = m2)
MLE <- cLaplace$findMLE()
expect_equal(MLE$value, cLaplace$calcLogLik(opt$par), tolerance = 0.04)
})
sink(NULL)
if(!generatingGoldFile) {
test_that("Log file matches gold file", {
trialResults <- readLines(tempFileName)
correctResults <- readLines(system.file(file.path('tests', 'testthat', goldFileName), package = 'nimble'))
compareFilesByLine(trialResults, correctResults)
})
}
options(warn = RwarnLevel)
options(digits = RdigitsOption)
nimbleOptions(verbose = nimbleVerboseSetting)
nimbleOptions(MCMCprogressBar = nimbleProgressBarSetting)
Try the nimble package in your browser
Any scripts or data that you put into this service are public.
nimble documentation built on June 22, 2024, 9:49 a.m.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
source(system.file(file.path('tests', 'testthat', 'test_utils.R'), package = 'nimble'))
RwarnLevel <- options('warn')$warn
options(warn = 1)
RdigitsOption <- options('digits')$digits
options(digits = 6)
nimbleVerboseSetting <- nimbleOptions('verbose')
nimbleOptions(verbose = TRUE)
nimbleProgressBarSetting <- nimbleOptions('MCMCprogressBar')
nimbleOptions(MCMCprogressBar = FALSE)
context("Testing of MCEM")
goldFileName <- 'mcemTestLog_Correct.Rout'
tempFileName <- 'mcemTestLog.Rout'
generatingGoldFile <- !is.null(nimbleOptions('generateGoldFileForMCEMtesting'))
outputFile <- if(generatingGoldFile) file.path(nimbleOptions('generateGoldFileForMCEMtesting'), goldFileName) else tempFileName
sink_with_messages(outputFile)
# Set up numerically precise MLE and vcov results
# for both regular and transformed coordinates
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:10) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pump_optim_trans <- optim(log(c(.75, 1.5)), pump_llh,
method = "BFGS", control = list(fnscale = -1),
hessian=TRUE, trans = TRUE)
pump_mle_trans <- pump_optim_trans$par
pump_vcov_trans <- inverse(-pump_optim_trans$hessian)
test_that("MCEM error-trapping", {
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta);
lambda[i] <- theta[i]*t[i];
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0);
beta ~ dgamma(0.1,1.0);
})
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pumpModel <- nimbleModel(code = pumpCode, constants = pumpConsts,
data = pumpData, inits = pumpInits,
buildDerivs=TRUE)
# Catch old syntax usage (for nimble < 1.2.0)
expect_error(pumpMCEM <- buildMCEM(model = pumpModel, burnIn=200))
# Correct message when boxConstraints will be ignored
expect_message(pumpMCEM <- buildMCEM(model = pumpModel,
control=list(boxConstraints = list(a = 1))),
"boxConstraints will be ignored")
# Catch when node setup is fully provided by some latent nodes don't exist.
defaultMargNodes <- setupMargNodes(pumpModel)
defaultMargNodes$randomEffectsNodes <- c(defaultMargNodes$randomEffectsNodes, "junk")
expect_error(pumpMCEM <- buildMCEM(model = pumpModel, paramNodes=defaultMargNodes))
})
test_that("MCEM pump with all defaults (roxygen example)", {
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta);
lambda[i] <- theta[i]*t[i];
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0);
beta ~ dgamma(0.1,1.0);
})
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22))
pumpInits <- list(alpha = 1, beta = 1,
theta = rep(0.1, pumpConsts$N))
pumpModel <- nimbleModel(code = pumpCode, constants = pumpConsts,
data = pumpData, inits = pumpInits,
buildDerivs=TRUE)
pumpMCEM <- buildMCEM(model = pumpModel)
CpumpModel <- compileNimble(pumpModel)
CpumpMCEM <- compileNimble(pumpMCEM, project=pumpModel)
set.seed(1)
MLE <- CpumpMCEM$findMLE()
vcov <- CpumpMCEM$vcov(MLE$par)
expect_equal(MLE$par, pump_mle, tol = 0.03)
expect_equal(vcov, pump_vcov, tol = 0.03)
samples <- as.matrix(CpumpMCEM$mvSamples)
expect_equal(ncol(samples), 10)
expect_true(nrow(samples)>=1000)
})
test_that("MCEM with pump transform=FALSE",{
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
# Although using the transformation or not is baked into the optimization
# the vcov procedure allows to return with or without it.
# In this case, there should be no difference since there is no
# transormation in use.
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans = TRUE)
expect_identical(vct, vc)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 500, maxM = 500, burnin = 100, maxIter = 1)
expect_false(abs(out$par[2] - pump_mle[2]) < .02)
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000,
burnin = 300, maxIter = 20, continue = TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check on the continue=TRUE feature and see if
# we get to convergence going one by one from the outside
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, burnin = 300,
Mfactor = 0.5, maxIter = 1)
for(i in 1:4)
out <- cpumpMCEM$findMLE(continue = TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
# Next check that it will run with ascent=FALSE
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, burnin = 300,
Mfactor = 0.5, ascent=FALSE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check that it will run with ascent=TRUE but
# meaningful limit set by maxM
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 2000, burnin = 300,
Mfactor = 0.5, ascent=TRUE)
expect_equal(out$par, pump_mle, tol = 0.03)
# Next check that it will run with minIter=2
# and also with C = 3 (converge at least three times)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 2000, burnin = 300,
Mfactor = 0.5, ascent=TRUE, minIter = 2,
C = 3)
expect_equal(out$par, pump_mle, tol = 0.03)
})
test_that("MCEM pump with transform=TRUE", {
# transformed version: Use parameter transformation
## build an MCEM algorithm with Ascent-based convergence criterion
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(burnin = 300,
mcmcControl = list(adaptInterval = 100),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform = TRUE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
## tol changed from .001 to .01 to make the test run faster
## Correspondingly expect_equal tolerance
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans=TRUE)
expect_equal(vct, pump_vcov_trans, tol=0.03)
# Now check when we request parameters returned on the transformed
# scale
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, returnTrans=TRUE)
expect_equal(out$par, pump_mle_trans, tol=0.01)
vc <- cpumpMCEM$vcov(out$par, trans = TRUE)
expect_equal(vc, pump_vcov_trans, tol=0.02)
vct <- cpumpMCEM$vcov(out$par, trans = TRUE, returnTrans=FALSE)
expect_equal(vct, pump_vcov, tol=0.03)
})
test_that("MCEM pump without AD, with transform=FALSE", {
####
# version without AD
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(useDerivs=FALSE,
burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=FALSE, resetSamples = TRUE, M = 10000)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans=FALSE, returnTrans = TRUE)
expect_identical(vc, vct)
})
test_that("MCEM pump without AD, with transform=TRUE", {
####
# version without AD
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta',
control = list(useDerivs=FALSE,
burnIn = 300,
mcmcControl = list(adaptInterval = 100),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=TRUE))
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
vct <- cpumpMCEM$vcov(out$par, trans = FALSE, returnTrans=TRUE)
expect_equal(vct, pump_vcov_trans, tol=0.03)
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, returnTrans = TRUE)
vc <- cpumpMCEM$vcov(out$par, trans=TRUE)
expect_equal(vc, pump_vcov_trans, tol = 0.03)
vc <- cpumpMCEM$vcov(out$par, trans=TRUE, returnTrans=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
## Test of case where some parts of the model
## are not related to missing data or latent states
test_that("MCEM with pump transform=FALSE and some calcNodesOther",{
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22),
theta = c(rep(NA, 8), .8, 1.2))
pumpInits <- list(alpha = 1, beta = 1,
theta = c(rep(0.1, pumpConsts$N-2), NA, NA))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:8) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
for(i in 9:10) {
llh <- llh + dgamma(pumpData$theta[i], shape = alpha, rate = beta, log=TRUE)
llh <- llh + dpois(pumpData$x[i], pumpData$theta[i], log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = TRUE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta[1:8]',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE))
expect_equal(length(pumpMCEM$E$calcNodesOther), 3)
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, C = 2)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE, atMLE=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
test_that("MCEM with pump transform=FALSE and some calcNodesOther, noAD",{
pumpConsts <- list(N = 10,
t = c(94.3, 15.7, 62.9, 126, 5.24,
31.4, 1.05, 1.05, 2.1, 10.5))
pumpData <- list(x = c(5, 1, 5, 14, 3, 19, 1, 1, 4, 22),
theta = c(rep(NA, 8), .8, 1.2))
pumpInits <- list(alpha = 1, beta = 1,
theta = c(rep(0.1, pumpConsts$N-2), NA, NA))
pump_llh <- function(p, trans = FALSE) {
# for theta ~ dgamma(shape = alpha, rate = beta)
# we get lambda = t*theta ~ dgamma(shape = alpha, rate = beta/t )
# For Y ~ dpois(lambda), marginal negative binomial
# has size = alpha and prob = (rate / (rate+1) = (beta/t) / (beta/t + 1) = beta / (beta+t))
alpha <- p[1]
beta <- p[2]
if(trans) {
alpha <- exp(alpha)
beta <- exp(beta)
}
llh <- 0
for(i in 1:8) {
size <- alpha
rate <- beta / pumpConsts$t[i]
prob <- rate / (rate + 1)
llh <- llh + dnbinom(pumpData$x[i], size = size, prob = prob, log=TRUE)
}
for(i in 9:10) {
llh <- llh + dgamma(pumpData$theta[i], shape = alpha, rate = beta, log=TRUE)
llh <- llh + dpois(pumpData$x[i], pumpData$theta[i], log=TRUE)
}
llh
}
pump_optim <- optim(c(.75, 1.5), pump_llh,
lower = c(0, 0), upper = c(Inf, Inf),
method = "L-BFGS-B", control = list(fnscale = -1),
hessian=TRUE)
pump_mle <- pump_optim$par
pump_vcov <- inverse(-pump_optim$hessian)
pumpCode <- nimbleCode({
for (i in 1:N){
theta[i] ~ dgamma(alpha,beta)
lambda[i] <- theta[i]*t[i]
x[i] ~ dpois(lambda[i])
}
alpha ~ dexp(1.0)
beta ~ dgamma(0.1,1.0)
})
pump <- nimbleModel(code = pumpCode, name = 'pump',
constants = pumpConsts,
data = pumpData,
inits = pumpInits,
# check = FALSE,
buildDerivs = FALSE)
cpump <- compileNimble(pump)
## Basic version: Use box constraints
## build an MCEM algorithm with Ascent-based convergence criterion
pumpMCEM <- buildMCEM(model = pump,
latentNodes = 'theta[1:8]',
control = list(burnIn = 300,
mcmcControl = list(adaptInterval = 100),
boxConstraints = list( list( c('alpha', 'beta'),
limits = c(0, Inf) ) ),
tol = 0.01, alpha = .01, beta = .01, gamma = .01,
buffer = 1e-6,
transform=FALSE,
useDerivs=FALSE))
expect_equal(length(pumpMCEM$E$calcNodesOther), 3)
cpumpMCEM <- compileNimble(pumpMCEM, project = pump)
# Run the basic MCEM that uses no transformation
set.seed(0)
cpump$alpha <- pump$alpha
cpump$beta <- pump$beta
out <- cpumpMCEM$findMLE(initM = 1000, maxM = 20000, Mfactor = 0.5, C = 2)
expect_equal(out$par, pump_mle, tol = 0.01)
vc <- cpumpMCEM$vcov(out$par, trans = FALSE, atMLE=FALSE)
expect_equal(vc, pump_vcov, tol = 0.03)
})
#######
# Adopting some (far from all) tests from test-ADlaplace
test_that("MCEM simplest 1D works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(a, sd = 2)
a ~ dnorm(mu, sd = 3)
mu ~ dnorm(0, sd = 5)
}), data = list(y = 4), inits = list(a = -1, mu = 0),
buildDerivs = TRUE
)
mMCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(mMCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE()
expect_equal(opt$par, 4, tol = .01)
vc <- cMCEM$vcov(opt$par)
# See test-ADlaplace for derivation
expect_equal(vc[1,1], 13, tol = .02)
})
test_that("MCEM simplest 1D with a constrained parameter works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(a, sd = 2)
a ~ dnorm(mu, sd = 3)
mu ~ dexp(1.0)
# I am not sure why Laplace works if init mu is 0 (log(0)=-Inf)
# but this doesn't. Both use BFGS.
}), data = list(y = 4), inits = list(a = -1, mu = 0.5),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE(C = 2)
vc <- cMCEM$vcov(opt$par)
# V[a] = 9
# V[y] = 9 + 4 = 13
# Cov[a, y] = V[a] = 9 (not needed)
# y ~ N(mu, 13)
# muhat = y = 4
# ahat = (9*y+4*mu)/(9+4) = y = 4
# Jacobian of ahat wrt transformed param log(mu) is 4/13*mu = 4*mu/13 = 16/13
# Hessian of joint loglik wrt a: -(1/4 + 1/9)
# Hessian of marginal loglik wrt transformed param log(mu) is (y*mu - 2*mu*mu)/13 = -4^2/13
# Variance of transformed param is 13/16
expect_equal(opt$par, 4, tol = 0.01)
# Covariance matrix (of mu and a) on transformed scale
vcov_transform <- matrix(c(0, 0, 0, 1/(1/4+1/9)), nrow = 2) + matrix(c(1, 16/13), ncol = 1) %*% (13/16) %*% t(matrix(c(1, 16/13), ncol = 1))
# Covariance matrix on original scale
vcov <- diag(c(4, 1)) %*% vcov_transform %*% diag(c(4, 1))
expect_equal(vcov[1,1], vc[1,1], tol = 0.1)
vct <- cMCEM$vcov(opt$par, returnTrans=TRUE)
expect_equal(vcov_transform[1,1], vct[1,1], tol = 0.03)
# Get results on transformed scale
set.seed(0)
cm$mu <- 0.5
opt <- cMCEM$findMLE(C = 2, returnTrans = TRUE)
expect_equal(opt$par, log(4), tol = 0.01)
vc <- cMCEM$vcov(opt$par, trans = TRUE, returnTrans = FALSE)
expect_equal(vcov[1,1], vc[1,1], tol = 0.1)
vct <- cMCEM$vcov(opt$par, trans = TRUE, returnTrans = TRUE)
expect_equal(vcov_transform[1,1], vct[1,1], tol = 0.03)
})
# Skipping " simplest 1D (constrained) with multiple data"
# The main difference there should be simply model structure
# that we don't need to test here.
test_that("MCEM simplest 1D with deterministic intermediates and multiple data works", {
set.seed(1)
m <- nimbleModel(
nimbleCode({
mu ~ dnorm(0, sd = 5)
a ~ dexp(rate = exp(0.5 * mu))
for (i in 1:5){
y[i] ~ dnorm(0.2 * a, sd = 2)
}
}), data = list(y = rnorm(5, 1, 2)), inits = list(mu = 2, a = 1),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
cm$mu <- 2
opt <- cMCEM$findMLE(C = 2)
vc <- cMCEM$vcov(opt$par)
# Results are checked using those from TMB
# See test-ADlaplace for checking results from TMB
# However, for this little toy, we get a slightly different estimate
# and so we check it with grid-based integration of the llh
#
#
## true_llh <- function(mu) {
## lambda <- exp(0.5 * mu)
## a_max <- qexp(0.9999, lambda)
## a_grid <- seq(0, a_max, length = 1000)
## delta_a <- diff(a_grid[1:2])
## a_grid <- a_grid[-1]-delta_a/2
## lh <- 0
## y <- cm$y
## for(i in 1:999) {
## llh_given_a <- dnorm(y, mean = 0.2*a_grid[i], sd = 2, log=TRUE) |>
## sum()
## lh <- lh + exp(llh_given_a) * dexp(a_grid[i], lambda)*delta_a
## }
## llh <- log(lh)
## llh
## }
## true_ans <- optimize(true_llh, lower=-4, upper=4, maximum=TRUE)
## true_mle <- true_ans$maximum # -2.856
## true_hess <- nimDerivs(true_llh(true_mle))
## true_var <- 1/(-true_hess$hessian[1,1,1]) # 8.150
## true_sd <- sqrt(true_var)
expect_equal(opt$par, -2.856, .04)
expect_equal(vc[1,1], 8.150, 0.1)
# Check covariance matrix for params only
})
# Case "1D with deterministic intermediates works" from Laplace seems redundant
test_that("MCEM 1D with a constrained parameter and deterministic intermediates works", {
m <- nimbleModel(
nimbleCode({
y ~ dnorm(0.2 * a, sd = 2)
a ~ dnorm(0.5 * mu, sd = 3)
mu ~ dexp(1.0)
}), data = list(y = 4), inits = list(a = -1, mu = 0.5),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE(tol = 0.0001)
vc <- cMCEM$vcov(opt$par)
# Correct answer first by direct integration and
# next by theory
## true_llh <- function(mu) {
## mean_a <- 0.5 * mu
## a_min <- qnorm(0.00001, mean = mean_a, sd = 3)
## a_max <- qnorm(0.99999, mean = mean_a, sd = 3)
## a_grid <- seq(a_min, a_max, length = 1000)
## delta_a <- diff(a_grid[1:2])
## a_grid <- a_grid[-1]-delta_a/2
## lh <- 0
## y <- cm$y
## for(i in 1:999) {
## llh_given_a <- dnorm(y, mean = 0.2*a_grid[i], sd = 2, log=TRUE) |>
## sum()
## lh <- lh + exp(llh_given_a) * dnorm(a_grid[i], mean_a, sd=3)*delta_a
## }
## llh <- log(lh)
## llh
## }
## true_ans <- optimize(true_llh, lower=20, upper=60, maximum=TRUE)
## true_mle <- true_ans$maximum # 40
## true_hess <- nimDerivs(true_llh(true_mle))
## true_var <- 1/(-true_hess$hessian[1,1,1]) # 436.007
## true_sd <- sqrt(true_var)
# And by theory
# V[a] = 9
# V[y] = 0.2^2 * 9 + 4 = 4.36
# y ~ N(0.2*0.5*mu, 4.36)
# muhat = y/(0.2*0.5) = 40
# ahat = (9*0.2*y + 4*0.5*mu)/(4+9*0.2^2) = 20
# Jacobian of ahat wrt transformed param log(mu) is 4*0.5*mu/(4+9*0.2^2) = 18.34862
# Hessian of joint loglik wrt a: -(0.2^2/4 + 1/9)
# Hessian of marginal loglik wrt param mu is -(0.2*0.5)^2/4.36
# Hessian of marginal loglik wrt transformed param log(mu) is (0.2*0.5*y*mu - 2*0.1^2*mu*mu)/4.36 = -3.669725
vcov_transform <- matrix(c(0, 0, 0, 1/(0.2^2/4+1/9)), nrow = 2) + matrix(c(1, 18.34862), ncol = 1) %*% (1/3.669725) %*% t(matrix(c(1, 18.34862), ncol = 1))
# Covariance matrix on original scale
vcov <- diag(c(40,1)) %*% vcov_transform %*% diag(c(40,1))
expect_equal(opt$par, 40, tol = 1)
expect_equal(vc[1,1], vcov[1,1], tol = 50) # out of 436
cm$mu <- 0.5
opt <- cMCEM$findMLE(tol = 0.0001, returnTrans = TRUE)
expect_equal(opt$par, log(40), tol = 0.02)
vc <- cMCEM$vcov(opt$par, trans=TRUE, returnTrans = TRUE, M = 50000)
expect_equal(vc[1,1], vcov_transform[1,1], tol = 0.1) #
})
# Skipping "with deterministic intermediates and multiple data works"
test_that("MCEM simplest 2x1D works, with multiple data for each", {
set.seed(1)
y <- matrix(rnorm(6, 4, 5), nrow = 2)
m <- nimbleModel(
nimbleCode({
for(i in 1:2) {
mu_y[i] <- 0.8*a[i]
for(j in 1:3)
y[i, j] ~ dnorm(mu_y[i], sd = 2)
a[i] ~ dnorm(mu_a, sd = 3)
}
mu_a <- 0.5 * mu
mu ~ dnorm(0, sd = 5)
}), data = list(y = y), inits = list(a = c(-2, -1), mu = 0),
buildDerivs = TRUE
)
MCEM <- buildMCEM(model = m)
cm <- compileNimble(m)
cMCEM <- compileNimble(MCEM, project = m)
set.seed(0)
opt <- cMCEM$findMLE()
expect_equal(opt$par, mean(y)/(0.8*0.5), tol = 0.04) # optim's reltol is about 1e-8 but that is for the value, not param.
vc <- cMCEM$vcov(opt$par)
## # V[a] = 9
## # V[y[i]] = 0.8^2 * 9 + 4 = 9.76
## # Cov[a, y[i]] = 0.8 * 9 = 7.2
## # Cov[y[i], y[j]] = 0.8^2 * 9 = 5.76, within a group
## Cov_A_Y <- matrix(nrow = 8, ncol = 8)
## Cov_A_Y[1, 1:8] <- c( 9, 0, 7.2, 7.2, 7.2, 0, 0, 0)
## Cov_A_Y[2, 1:8] <- c( 0, 9, 0, 0, 0, 7.2, 7.2, 7.2)
## Cov_A_Y[3, 1:8] <- c(7.2, 0, 9.76, 5.76, 5.76, 0, 0, 0)
## Cov_A_Y[4, 1:8] <- c(7.2, 0, 5.76, 9.76, 5.76, 0, 0, 0)
## Cov_A_Y[5, 1:8] <- c(7.2, 0, 5.76, 5.76, 9.76, 0, 0, 0)
## Cov_A_Y[6, 1:8] <- c( 0, 7.2, 0, 0, 0, 9.76, 5.76, 5.76)
## Cov_A_Y[7, 1:8] <- c( 0, 7.2, 0, 0, 0, 5.76, 9.76, 5.76)
## Cov_A_Y[8, 1:8] <- c( 0, 7.2, 0, 0, 0, 5.76, 5.76, 9.76)
## Cov_Y <- Cov_A_Y[3:8, 3:8]
## chol_cov <- chol(Cov_Y)
## res <- dmnorm_chol(as.numeric(t(y)), mean(y), cholesky = chol_cov, prec_param=FALSE, log = TRUE)
## expect_equal(opt$value, res)
## # muhat = mean(y)/(0.8*0.5)
## # ahat[1] = (9*0.8*sum(y[1,]) + 4*0.5*mu)/(4+9*0.8^2*3)
## # ahat[2] = (9*0.8*sum(y[2,]) + 4*0.5*mu)/(4+9*0.8^2*3)
## # Jacobian of ahat[i] wrt mu is 4*0.5/(4+9*0.8^2*3) = 0.09398496
## # Hessian of joint loglik wrt a[i]a[i]: -(3*0.8^2/4 + 1/9); wrt a[i]a[j]: 0
## # Hessian of marginal loglik wrt mu: -0.04511278 (numerical, have not got AD work)
muhat <- mean(y)/(0.8*0.5)
# Covariance matrix
vcov <- diag(c(0, rep(1/(3*0.8^2/4 + 1/9), 2))) + matrix(c(1, rep(0.09398496, 2)), ncol = 1) %*% (1/0.04511278) %*% t(matrix(c(1, rep(0.09398496, 2)), ncol = 1))
expect_equal(vcov[1,1], vc[1,1], tol = 0.02)
## Check covariance matrix for params only
})
#skipping " with 2x1D random effects needing joint integration works, without intermediate nodes"
# and "Laplace with 2x1D random effects needing joint integration works, with intermediate nodes"
# This case would need more attention
# The MCEM convergence path is painfully slow.
# It might be better with a reparameterization.
# But for now it is thought that this test is not really needed
# for any specific functionality.
## test_that("MCEM with 2x2D random effects for 1D data that are separable works, with intermediate nodes", {
## # This example gives a really bad MCEM convergence path
## set.seed(1)
## # y[i, j] is jth datum from ith group
## y <- array(rnorm(8, 6, 5), dim = c(2, 2, 2))
## cov_a <- matrix(c(2, 1.5, 1.5, 2), nrow = 2)
## m <- nimbleModel(
## nimbleCode({
## for(i in 1:2) mu[i] ~ dnorm(0, sd = 10)
## mu_a[1] <- 0.8 * mu[1]
## mu_a[2] <- 0.2 * mu[2]
## for(i in 1:2) a[i, 1:2] ~ dmnorm(mu_a[1:2], cov = cov_a[1:2, 1:2])
## for(i in 1:2) {
## for(j in 1:2) {
## y[1, j, i] ~ dnorm( 0.5 * a[i, 1], sd = 1.8) # this ordering makes it easier below
## y[2, j, i] ~ dnorm( 0.1 * a[i, 2], sd = 1.2)
## }
## }
## }),
## data = list(y = y),
## inits = list(a = matrix(c(-2, -3, 0, -1), nrow = 2), mu = c(0, .5)),
## constants = list(cov_a = cov_a),
## buildDerivs = TRUE
## )
## MCEM <- buildMCEM(model = m)
## cm <- compileNimble(m)
## cMCEM <- compileNimble(MCEM, project = m)
## Laplace <- buildLaplace(m)
## cLaplace <- compileNimble(Laplace, project = m)
## MLE <- cLaplace$findMLE()
## cLaplace$calcLogLik(c(12.9840, 405.9512))
## cLaplace$calcLogLik(c(12.2434, 391.044))
## # this takes a long time. the convergence path is poor.
## set.seed(0)
## cm$mu <- c(0, 0.5)
## opt <- cMCEM$findMLE(alpha = 0.1, maxIter = 300, maxM = 50000)
## })
test_that("MCMC for simple LME case works", {
set.seed(1)
g <- rep(1:10, each = 5)
n <- length(g)
x <- runif(n)
mc <- nimbleCode({
for(i in 1:n) {
y[i] ~ dnorm((random_int[g[i]]) +
(random_slope[g[i]])*x[i], sd = sigma_res)
}
for(i in 1:ng) {
random_int[i] ~ dnorm(fixed_int , sd = sigma_int)
random_slope[i] ~ dnorm(fixed_slope, sd = sigma_slope)
}
sigma_int ~ dhalfflat() #dunif(0, 10)
sigma_slope ~ dhalfflat() #dunif(0, 10)
sigma_res ~ dhalfflat() #dunif(0, 10)
fixed_int ~ dnorm(0, sd = 100)
fixed_slope ~ dnorm(0, sd = 100)
})
m <- nimbleModel( mc,
constants = list(g = g, ng = max(g), n = n, x = x),
buildDerivs = TRUE
)
params <- c("fixed_int", "fixed_slope", "sigma_int", "sigma_slope", "sigma_res")
values(m, params) <- c(10, 0.5, 3, .25, 0.2)
m$simulate(m$getDependencies(params, downstream = TRUE, self = FALSE))
m$setData('y')
y <- m$y
cm <- compileNimble(m)
# We can do this by lme4, but instead we'll use nimble's Laplace
#library(lme4)
#manual_fit <- lmer(y ~ x + (1 + x || g), REML = FALSE)
#data <- data.frame(y = y, x = x, g = g)
# The reason to use our Laplace is to compare MLEs in terms of
# the log likelihood itself.
MCEM <- buildMCEM(model = m, latentNodes = c("random_int", "random_slope"),
control = list(
mcmcControl = list(adaptInterval = 20)))
cMCEM <- compileNimble(MCEM, project = m)
set.seed(1)
values(cm, params) <- c(0, 0, 1, 1, 1)
opt <- cMCEM$findMLE(maxIter = 2000, initM = 1000, burnin = 300,
maxM = 50000, tol = 0.001)
m2 <- nimbleModel( mc,
constants = list(g = g, ng = max(g), n = n, x = x),
data = list(y = m$y),
buildDerivs = TRUE
)
for(v in m2$getVarNames()) m2[[v]] <- m[[v]]
m2$calculate()
cm2 <- compileNimble(m2)
Laplace <- buildLaplace(model=m2, randomEffectsNodes = c("random_int", "random_slope"))
cLaplace <- compileNimble(Laplace, project = m2)
MLE <- cLaplace$findMLE()
expect_equal(MLE$value, cLaplace$calcLogLik(opt$par), tolerance = 0.04)
})
sink(NULL)
if(!generatingGoldFile) {
test_that("Log file matches gold file", {
trialResults <- readLines(tempFileName)
correctResults <- readLines(system.file(file.path('tests', 'testthat', goldFileName), package = 'nimble'))
compareFilesByLine(trialResults, correctResults)
})
}
options(warn = RwarnLevel)
options(digits = RdigitsOption)
nimbleOptions(verbose = nimbleVerboseSetting)
nimbleOptions(MCMCprogressBar = nimbleProgressBarSetting)
Try the nimble package in your browser
Any scripts or data that you put into this service are public.
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
Embedding an R snippet on your website
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.