issue with disag_model() function from disaggregation R package - r

Question

I was trying to use the disaggregation package to evaluate if it could be used on the dataset I have. My original data are disaggregated, so I've aggregated them to use the disag_model function from disaggregation package and compare "fitted values" with actual values.
However when I run the function the R session aborts.
I tried to execute the disag_model function step by step and I saw that the problem is due to the use of nlminb() to optimize the a posteriori density function, but I cannot understand why it's happening and how to solve it.
Thanks for your help.
You can find the data I used at this link: https://www.dropbox.com/sh/au7l0e11trzfo19/AACpfRSUpd4gRCveUsh5JX6Ea?dl=0
Please download the folder to run the code.
This is the code I used:
library(tidyverse)
library(raster)
library(disaggregation)
library(sp)
path<- "yourPath/Data"
load(file.path(path, "myRS"))
load(file.path(path, "RAST"))
Data <- read.csv(file = paste(path, "/sim_data.csv", sep = ""))
Data$HasRes <- ifelse(Data$PN50 > runif(nrow(Data)), 1, 0)
for (i in 1:nlayers(myRS)) {
myRS#layers[[i]]#file#name<-file.path(path, "predStackl10")
}
DFCov <-
as.data.frame(raster::extract(myRS, Data[c("XCoord", "YCoord")]))
Data <- cbind(Data, DFCov)
# Remove NA
NAs <- which(is.na(rowSums(Data[names(myRS)])))
Data <- Data[-NAs, ]
Data$ISO3 <- as.factor(Data$ISO3)
world_shape <-
shapefile(file.path(path, "World.shp"))
lmic_shape <-
world_shape[(world_shape#data$ISO3 %in% levels(Data$ISO3)),]
plot(lmic_shape)
# I would like to convert Data in a SpatialPointsDataFrame object
PN50 <- Data
coordinates(PN50) <- c("XCoord", "YCoord")
is.projected(PN50) # see if a projection is defined
proj4string(PN50) <- CRS("+proj=longlat +datum=WGS84")
# compute the mean P50 within each state
PN50_mean <- aggregate(x = PN50,
by = list(Data$ISO3),
FUN = mean)
# compute the centroid of the observations coordinates for each state
PN50_centroid <-
Data %>% group_by(ISO3) %>% summarise(meanX = mean(XCoord), meanY = mean(YCoord))
# assign to each mean the centroid coordinates
PN50_agg <-
as.data.frame(
cbind(
PN50_mean = PN50_mean#data$PN50,
XCoord = PN50_centroid$meanX,
YCoord = PN50_centroid$meanY
)
)
PN50_agg$XCoord <- as.numeric(PN50_agg$XCoord)
PN50_agg$YCoord <- as.numeric(PN50_agg$YCoord)
PN50_agg$ISO3 <- as.character(PN50_centroid$ISO3)
samsiz <-
Data %>% group_by(ISO3) %>% summarise(sz = sum(SampleSize))
PN50_agg$sample_size <- as.numeric(samsiz$sz)
PN50_agg$case <- round(PN50_agg$PN50_mean * PN50_agg$sample_size)
# I would like having data in a SpatialPolygonsDataFrame format to use the disaggrgation package
library(sp)
coordinates(PN50_agg) <- c("XCoord", "YCoord")
proj4string(PN50_agg) <- CRS("+proj=longlat +datum=WGS84")
PN50_polyg <- lmic_shape
PN50_polyg#data <-
full_join(PN50_polyg#data, PN50_agg#data, by = "ISO3")
# covariates raster
covariate_stack <-
getCovariateRasters(path, shape = raster(x = paste0(path, '/multi.tif')))
names(covariate_stack)
covariate_stack2 <- dropLayer(covariate_stack, nlayers(covariate_stack))
names(covariate_stack2)
plot(covariate_stack2)
covariate_stack2 <- raster::stack(covariate_stack2)
covariate_stack2<-brick(covariate_stack2)
# population raster
extracted <- raster::extract(raster(x = paste0(path, '/multi.tif')), PN50_polyg)
n_cells <- sapply(extracted, length)
PN50_polyg#data$pop_per_cell <- PN50_polyg#data$sample_size / n_cells
population_raster <-
rasterize(PN50_polyg, covariate_stack2, field = 'pop_per_cell')
# prepare data for disag_model()
dis_data <- prepare_data(
polygon_shapefile = PN50_polyg,
covariate_rasters = covariate_stack2,
aggregation_raster = population_raster,
mesh.args = list(
max.edge = c(5, 40),
cut = 0.0005,
offset = 1
),
id_var = "ISO3",
response_var = "case",
sample_size_var = "sample_size",
na.action = TRUE,
ncores = 8
)
# Rho and p(Rho<Rho_min)
dist <- pointDistance(PN50_agg#coords, lonlat = F, allpairs = T)
rownames(dist) <- PN50_agg$ISO3
colnames(dist) <- PN50_agg$ISO3
flattenDist <- function(dist) {
up <- upper.tri(dist)
flat <- data_frame(row = rownames(dist)[row(dist)[up]],
column = rownames(dist)[col(dist)[up]],
dist = dist[up])
return(flat)
}
pair_dist <- flattenDist(dist)
d <- pair_dist$dist
k <- 0.036
CorMatern <- k * d * besselK(k * d, 1)
limits <- sp::bbox(PN50_polyg)
hypontenuse <-
sqrt((limits[1, 2] - limits[1, 1]) ^ 2 + (limits[2, 2] - limits[2, 1]) ^
2)
prior_rho <- hypontenuse / 3
p_rho <- sum(d[CorMatern <= 0.1] < prior_rho) / length(d[CorMatern <= 0.1])
# sigma and p(sigma>sigma_max)
sigma_boost <- function(data, i) {
sd(data[i] / mean(data[i]))
}
sigma <-
boot(data = dis_data$polygon_data$response,
statistic = sigma_boost,
10000)
prior_sigma <- sigma$t0
p_sigma <- sum(sigma$t >= sigma$t0) / length(sigma$t)
default_priors <-
list(
priormean_intercept = 0,
priorsd_intercept = 4,
priormean_slope = 0,
priorsd_slope = 2,
prior_rho_min = prior_rho,
prior_rho_prob = p_rho,
prior_sigma_max = prior_sigma,
prior_sigma_prob = p_sigma,
prior_iideffect_sd_max = 0.1,
prior_iideffect_sd_prob = 0.01
)
fitted_model <- disag_model(
data = dis_data,
iterations = 1000,
family = "binomial",
link = "logit",
# priors = default_priors,
field = TRUE,
iid = TRUE,
silent = TRUE
)

Answer 1

I was able to run the disag_model function using your dis_data object. There were no errors or crashes. I ran the following lines.
fitted_model <- disag_model(
data = dis_data,
iterations = 1000,
family = "binomial",
link = "logit",
field = TRUE,
iid = TRUE,
silent = TRUE
)
I am running on a Windows machine with 64GB RAM and 8 cores. It took over an hour and used all of my RAM for a while and up to 50% of my CPU, which is not surprising as you are fitting 5.5M pixels over the whole world. Therefore, I suspect it is related to your computer running out of resources. I suggest you try a smaller example to test it out first. Try fewer polygons and fewer pixels in each polygon.