library(ncdf4)
library(lattice)
library(Metrics)

mydatar.nc <- nc_open("T2_daily_1982_2years")
mydatar <- ncvar_get(mydatar.nc,"T2")

mydata1.nc <- nc_open("T2_daily_1982_6months")
mydata1 <- ncvar_get(mydata1.nc,"T2")

### pooling together all grid points
xr=c(mydatar[,,])
x1=c(mydata1[,,])
aux <- ks.test(xr, x1)

### testing the spatilally averaged series
avgr <- apply(mydatar,c(3),mean)
avg1 <- apply(mydata1,c(3),mean)
aux <- ks.test(avgr, avg1)

### testing the series at the grid-point level
lon <- mydatar.nc$dim$x$vals
lat <- mydatar.nc$dim$y$vals
ncol <- length(lat)
nrow <- length(lon)
pval=0.05
ksp <- matrix(data=NA,nrow=nrow,ncol=ncol)
for (i in 1:nrow){
  for (j in 1:ncol){
    aux <- ks.test(mydatar[i,j,], mydata1[i,j,])
    ksp[i,j] = aux$p.value
    if (ksp[i,j]<pval) {
      ksp[i,j]=0
    } else {
      ksp[i,j]=1
    }  
  }
}