In MariekeDirk/GeoInterpolation: Temperature Interpolation methods

knitr::opts_chunk$set(echo = TRUE,message=FALSE)

Functions and libraries

library(raster)
library(data.table)
files.dir <- "/nobackup/users/dirksen/KNMI2014/KNMI14_schetsboeken/"

#knmi2014.files <- list.files(path=files.dir,pattern="tg",full.names=TRUE)
klimaatKNMI <- function(filetxt,varname){
  filetxt<-t(filetxt)
  filetxt<-data.table(filetxt,keep.rownames = TRUE)
  filetxt<-drop(filetxt[2:26,])
  names(filetxt)<-c("stn","RDx","RDy","lat","lon",varname)
  return(filetxt)
}

Reading the data

tg<-fread(paste0(files.dir,"klimaat_KNMI14____ref__tg.av____annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
          colClasses=rep("character",26))
tg.varname <- "Tg"

tn<-fread(paste0(files.dir,"klimaat_KNMI14____ref__tn.av____annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
          colClasses=rep("character",26))
tn.varname <- "Tn"

tx<-fread(paste0(files.dir,"klimaat_KNMI14____ref__tx.av____annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
          colClasses=rep("character",26))
tx.varname <- "Tx"

Nwarm<-fread(paste0(files.dir,"klimaat_KNMI14____ref__N_warm___annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
             colClasses=rep("character",26))
Nwarm.varname <- "Nwarm"

Ntrop<-fread(paste0(files.dir,"klimaat_KNMI14____ref__N_trop___annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
             colClasses=rep("character",26))
Ntrop.varname <- "Ntrop"

Nvorst<-fread(paste0(files.dir,"klimaat_KNMI14____ref__N_vorst__annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
             colClasses=rep("character",26))
Nvorst.varname <- "Nvorst"

Nijs<-fread(paste0(files.dir,"klimaat_KNMI14____ref__N_ijs____annual_19810101-20101231_v1.0.txt"),header=TRUE,sep=" ",
             colClasses=rep("character",26))
Nijs.varname <- "Nijs"

Merge all the data

Tg <- klimaatKNMI(tg,tg.varname)
Tn <- klimaatKNMI(tn,tn.varname)
Tx <- klimaatKNMI(tx,tx.varname)
Warm_days <- klimaatKNMI(Nwarm,Nwarm.varname)
Vrost_days <-klimaatKNMI(Nvorst,Nvorst.varname)
Trop_days <- klimaatKNMI(Ntrop,Ntrop.varname)
Ijs_days <- klimaatKNMI(Nijs,Nijs.varname)

list.of.data.frames<-list(Tg,Tn,Tx,Warm_days,Vrost_days,Trop_days,Ijs_days)

out<-Reduce(function(x,y) merge(x,y,by=c("stn","RDx","RDy","lat","lon"),all=TRUE),list.of.data.frames)

out<-data.frame(out)
cols.num <- c("Tg","Tn","Tx","Nwarm","Nvorst","Ntrop","Nijs","RDx","RDy")
out[cols.num] <- sapply(out[cols.num],as.numeric)

out$lat <- out$RDx*1000
out$lon <- out$RDy*1000

Correlation between variables

library(corrplot)
outsubset<-subset(out,select=cols.num)
M<-cor(outsubset)
corrplot(M,method="circle")

Other plotting routine

plot(out$Tg,out$Nwarm,pch="o",col="red",xlab="number of warm days",ylab="mean temperature")
plot(out$Tg,out$Nvorst,pch="o",col="blue",xlab="number of vrost days",ylab="mean temperature")