parallel

library(dplyr)
library(dggridR)


library(rgeos)
library(rgdal)
library(raster)

library(sf)
library(sp)

library(SpaDES)

library(parallel)
library(foreach)
library(doSNOW)

###############################################################

setwd('F:/DGG/Bio/Tsue_GIS')

############################saving raster###################################
rast=raster("Dem.tif")
path=paste('F:/DGG/Bio/Tsue_GIS')

ncpu=detectCores()
cl=makeCluster(ncpu-1)
registerDoSNOW(cl)
rlist=splitRaster(rast, nx=50, ny=50, 0,buffer = c(2, 2), path=path,cl=cl)
#rast = projectRaster(rast, crs = "+proj=longlat +ellps=GRS80 +units=m +datum=WGS84")
dggs= dgconstruct(res=22, metric=FALSE, resround='nearest',pole_lat_deg = 37,pole_lon_deg =-178)

clusterEvalQ(cl, library(dggridR)) 
clusterEvalQ(cl, library(raster))

foreach (i=1:2500) %dopar% {
#for (i in 1:100){
ind=which(!is.na(rlist[[i]][]))

if (length(ind)>0){
xy = xyFromCell(rlist[[i]], ind, spatial=FALSE)
z=rlist[[i]][ind]
df = data.frame(VALUE=z)


df$dggid = dgGEO_to_SEQNUM(dggs, xy[,1], xy[,2])$seqnum

data=aggregate.data.frame(df, by=list(df$dggid),mean)

data$Group.1=NULL

name=paste(path,'/RAST_22_',i,'.csv',sep="")
write.csv(data,name,sep=';', row.names=FALSE)


}
print (i)
}
stopCluster(cl)