I have been trying to calculate the monthly means of 8day MODIS data and it is taking very long to calculate the mean. Is there a faster way to do this. I am using the following code to do it in R:
library(doParallel)
library(foreach)
library(raster)
# Set the number of cores to use for parallel processing
ncores <- parallel::detectCores() - 1 # Use all available cores except one
registerDoParallel(cores = ncores)
m<-stack()
foreach (month_name = month.name) %dopar% {
print(month_name)
# Subset layers corresponding to the current month
month_layers <- s[[which(months(getZ(s)) == month_name)]]
print(month_layers)
# Calculate mean for the month (exclude NA values)
month_mean <- mean(month_layers, na.rm = TRUE)
print(month_mean)
# Store the monthly mean in the list with the month name as the list element name
m<-stack(m,month_mean)
}
I would do
library(terra)
x <- rast(files)
m <- tapp(x, "months", mean, cores=ncores)