##################    Interpolation of Tmax Using Kriging  #######################################

########################### Kriging and Cokriging   ###############################################

#This script interpolates station values for the Oregon case study using Kriging and Cokring.    #

#The script uses LST monthly averages as input variables and  loads the station data             # 

#from a shape file with projection information.                                                  #

#Note that this program:                                                                         #

#1)assumes that the shape file is in the current working.                                        # 

#2)relevant variables were extracted from raster images before performing the regressions        #

#  and stored shapefile                                                                          #

#This scripts predicts tmax using autokrige, gstat and LST derived from MOD11A1.                 #

#also included and assessed using the RMSE,MAE,ME and R2 from validation dataset.                #

#TThe dates must be provided as a textfile.                                                      #

#AUTHOR: Benoit Parmentier                                                                       #

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

###Loading R library and packages                                                      

#library(gtools)                                         # loading some useful tools 

library(mgcv)                                           # GAM package by Wood 2006 (version 2012)

library(sp)                                             # Spatial pacakge with class definition by Bivand et al. 2008

library(spdep)                                          # Spatial pacakge with methods and spatial stat. by Bivand et al. 2012

library(rgdal)                                          # GDAL wrapper for R, spatial utilities (Keitt et al. 2012)

library(gstat)                                          # Kriging and co-kriging by Pebesma et al. 2004

library(automap)                                        # Automated Kriging based on gstat module by Hiemstra et al. 2008

library(gpclib)

library(maptools)

infile2<-"list_10_dates_04212012.txt"                     #List of 10 dates for the regression

#infile2<-"list_365_dates_04212012.txt"

infile3<-"LST_dates_var_names.txt"                        #LST dates name

infile4<-"models_interpolation_05142012.txt"              #Interpolation model names

inlistf<-"list_files_05032012.txt"                        #Stack of images containing the Covariates

prop<-0.3                                                                       #Proportion of testing retained for validation   

seed_number<- 100                                                               #Seed number for random sampling

###STEP 1 DATA PREPARATION AND PROCESSING#####

filename<-sub(".shp","",infile1)             #Removing the extension from file.

ghcn<-readOGR(".", filename)                 #reading shapefile 

CRS<-proj4string(ghcn)                       #Storing projection information (ellipsoid, datum,etc.)

mean_LST<- readGDAL(infile5)                 #Reading the whole raster in memory. This provides a grid for kriging

proj4string(mean_LST)<-CRS                   #Assigning coordinate information to prediction grid.

lines<-read.table(paste(path,"/",inlistf,sep=""), sep=" ")                  #Column 1 contains the names of raster files

inlistvar<-lines[,1]

inlistvar<-paste(path,"/",as.character(inlistvar),sep="")

covar_names<-as.character(lines[,2])                                         #Column two contains short names for covaraites

s_raster<- stack(inlistvar)                                                  #Creating a stack of raster images from the list of variables.

layerNames(s_raster)<-covar_names                                            #Assigning names to the raster layers

projection(s_raster)<-CRS

#stat_val<- extract(s_raster, ghcn3)                                          #Extracting values from the raster stack for every point location in coords data frame.

pos<-match("ASPECT",layerNames(s_raster)) #Find column with name "value"

r1<-raster(s_raster,layer=pos)             #Select layer from stack

pos<-match("slope",layerNames(s_raster)) #Find column with name "value"

r2<-raster(s_raster,layer=pos)             #Select layer from stack

N<-cos(r1*pi/180)

E<-sin(r1*pi/180)

Nw<-sin(r2*pi/180)*cos(r1*pi/180)   #Adding a variable to the dataframe

Ew<-sin(r2*pi/180)*sin(r1*pi/180)   #Adding variable to the dataframe.

r<-stack(N,E,Nw,Ew)

rnames<-c("Northness","Eastness","Northness_w","Eastness_w")

layerNames(r)<-rnames

s_raster<-addLayer(s_raster, r)

s_sgdf<-as(s_raster,"SpatialGridDataFrame") #Conversion to spatial grid data frame

### adding var

ghcn = transform(ghcn,Eastness = sin(ASPECT*pi/180))  #adding variable to the dataframe.

ghcn = transform(ghcn,Northness_w = sin(slope*pi/180)*cos(ASPECT*pi/180)) #Adding a variable to the dataframe

ghcn = transform(ghcn,Eastness_w = sin(slope*pi/180)*sin(ASPECT*pi/180))  #adding variable to the dataframe.

#Remove NA for LC and CANHEIGHT

ghcn$LC1[is.na(ghcn$LC1)]<-0

ghcn$LC3[is.na(ghcn$LC3)]<-0

ghcn$CANHEIGHT[is.na(ghcn$CANHEIGHT)]<-0

set.seed(seed_number)                        #Using a seed number allow results based on random number to be compared...

dates <-readLines(paste(path,"/",infile2, sep=""))

LST_dates <-readLines(paste(path,"/",infile3, sep=""))

#models<-5

results_AIC<- matrix(1,length(dates),models+3)  

results_GCV<- matrix(1,length(dates),models+3)

#Model assessment: general diagnostic/metrics 

results_RMSE <- matrix(1,length(dates),models+3)

results_MAE <- matrix(1,length(dates),models+3)

results_ME <- matrix(1,length(dates),models+3)

results_R2 <- matrix(1,length(dates),models+3)       #Coef. of determination for the validation dataset

results_RMSE_f<- matrix(1,length(dates),models+3)

#ghcn$value<-as.numeric(ghcn$value)

ghcn_all<-ghcn

ghcn_test<-subset(ghcn,ghcn$value>-150 & ghcn$value<400)

ghcn_test2<-subset(ghcn_test,ghcn_test$ELEV_SRTM>0)

ghcn<-ghcn_test2

#coords<- ghcn[,c('x_OR83M','y_OR83M')]

ghcn.subsets <-lapply(dates, function(d) subset(ghcn, ghcn$date==as.numeric(d)))   #Producing a list of data frame, one data frame per date.

#i<-3                                           #Date 10 is used to test kriging

  #This allows to change only one name of the 

  month<-strftime(date, "%m")

  LST_month<-paste("mm_",month,sep="")

  #t<-s_sgdf[,match(LST_month, names(s_sgdf))]

  #s_sgdf$LST<-s_sgdf[c(LST_month)]

  ghcn.subsets[[i]]$LST <-mod[[1]]

  ns<-n-round(n*prop)                             #Create a sample from the data frame with 70% of the rows

  nv<-n-ns                                        #create a sample for validation with prop of the rows

  ind.training <- sample(nrow(ghcn.subsets[[i]]), size=ns, replace=FALSE)  #This selects the index position for 70% of the rows taken randomly

  ind.testing <- setdiff(1:nrow(ghcn.subsets[[i]]), ind.training)         #This selects the index position for testing subset stations.

  data_s <- ghcn.subsets[[i]][ind.training, ]

  data_v <- ghcn.subsets[[i]][ind.testing, ]

  ###BEFORE Kringing the data object must be transformed to SDF

  coords<- data_v[,c('x_OR83M','y_OR83M')]

  coordinates(data_v)<-coords

  proj4string(data_v)<-CRS  #Need to assign coordinates...

  coords<- data_s[,c('x_OR83M','y_OR83M')]

  coordinates(data_s)<-coords

  proj4string(data_s)<-CRS  #Need to assign coordinates..

  #This allows to change only one name of the data.frame

  pos<-match("value",names(data_s)) #Find column with name "value"

  names(data_s)[pos]<-c("tmax")

  data_s$tmax<-data_s$tmax/10                #TMax is the average max temp for months

  pos<-match("value",names(data_v)) #Find column with name "value"

  names(data_v)[pos]<-c("tmax")

  data_v$tmax<-data_v$tmax/10

  #dstjan=dst[dst$month==9,]  #dst contains the monthly averages for tmax for every station over 2000-2010

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

  #Kriging tmax

#   v<-variogram(tmax~1, data_s)                           # This plots a sample varigram for date 10 fir the testing dataset

#   plot(v)

#   v.fit<-fit.variogram(v,vgm(2000,"Sph", 150000,1000))   #Model variogram: sill is 2000, spherical, range 15000 and nugget 1000

#   plot(v, v.fit)                                         #Compare model and sample variogram via a graphical plot

#   tmax_krige<-krige(tmax~1, data_s,mean_LST, v.fit)      #mean_LST provides the data grid/raster image for the kriging locations to be predicted.

  krmod2<-autoKrige(tmax~x_OR83M+y_OR83M,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krmod3<-autoKrige(tmax~x_OR83M+y_OR83M+ELEV_SRTM,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krmod4<-autoKrige(tmax~x_OR83M+y_OR83M+DISTOC,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krmod5<-autoKrige(tmax~x_OR83M+y_OR83M+ELEV_SRTM+DISTOC,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krmod6<-autoKrige(tmax~x_OR83M+y_OR83M+Northness+Eastness,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krmod7<-autoKrige(tmax~x_OR83M+y_OR83M+Northness+Eastness,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  #krmod8<-autoKrige(tmax~LST,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  #krmod9<-autoKrige(tmax~x_OR83M+y_OR83M+LST,input_data=data_s,new_data=s_sgdf,data_variogram=data_s)

  krig2<-krmod2$krige_output

  krig3<-krmod3$krige_outpu

  krig4<-krmod4$krige_output

  krig5<-krmod5$krige_output

  krig7<-krmod7$krige_output

  #krig8<-krmod8$krige_outpu

  #krig9<-krmod9$krige_output

  #tmax_krig1_v <- overlay(krige,data_v)

#   

#   #Cokriging tmax

#   g<-gstat(NULL,"tmax", tmax~1, data_s)                   #This creates a gstat object "g" that acts as container for kriging specifications.

#   g<-gstat(g, "SRTM_elev",ELEV_SRTM~1,data_s)            #Adding variables to gstat object g

#   g<-gstat(g, "LST", LST~1,data_s)

#   vm_g.fit<-fit.lmc(vm_g,g,vgm(2000,"Sph", 100000,1000)) #Fitting variogram for all variables at once.

#   plot(vm_g,vm_g.fit)                                    #Visualizing variogram fit and sample

#   vm_g.fit$set <-list(nocheck=1)                         #Avoid checking and allow for different range in variogram

#   co_kriged_surf<-predict(vm_g.fit,mean_LST) #Prediction using co-kriging with grid location defined from input raster image.

#   #co_kriged_surf$tmax.pred                              #Results stored in SpatialGridDataFrame with tmax prediction accessible in dataframe.

#   tmax_cokrig1_s<- overlay(co_kriged_surf,data_s)        #This overalys the cokriged surface tmax and the location of weather stations

#   tmax_cokrig1_v<- overlay(co_kriged_surf,data_v)

    krmod<-get(mod)

    krig_val_v <- overlay(krmod,data_v)             #This overlays the kriged surface tmax and the location of weather stations

    pred_krmod<-paste("pred_krmod",j,sep="")

    #Adding the results back into the original dataframes.

    data_s[[pred_krmod]]<-krig_val_s$var1.pred

    data_v[[pred_krmod]]<-krig_val_v$var1.pred  

    #Model assessment: RMSE and then krig the residuals....!

    res_mod_kr_s<- data_s$tmax - data_s[[pred_krmod]]           #Residuals from kriging training

    res_mod_kr_v<- data_v$tmax - data_v[[pred_krmod]]           #Residuals from kriging validation

    RMSE_mod_kr_s <- sqrt(sum(res_mod_kr_s^2,na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_s))))         #RMSE from kriged surface training

    RMSE_mod_kr_v <- sqrt(sum(res_mod_kr_v^2,na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_v))))         #RMSE from kriged surface validation

    MAE_mod_kr_s<- sum(abs(res_mod_kr_s),na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_s)))        #MAE from kriged surface training                    #MAE, Mean abs. Error FOR REGRESSION STEP 1: GAM   

    MAE_mod_kr_v<- sum(abs(res_mod_kr_v),na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_v)))        #MAE from kriged surface validation

    ME_mod_kr_s<- sum(res_mod_kr_s,na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_s)))                    #ME, Mean Error or bias FOR REGRESSION STEP 1: GAM

    ME_mod_kr_v<- sum(res_mod_kr_v,na.rm=TRUE)/(nv-sum(is.na(res_mod_kr_v)))                    #ME, Mean Error or bias FOR REGRESSION STEP 1: GAM

    R2_mod_kr_v<- cor(data_v$tmax,data_v[[pred_krmod]],use="complete.obs")^2                  #R2, coef. of determinationFOR REGRESSION STEP 1: GAM

    #Writing out results

    results_RMSE[i,1]<- dates[i]  #storing the interpolation dates in the first column

    results_RMSE[i,2]<- ns        #number of stations used in the training stage

    results_RMSE[i,3]<- "RMSE"

    results_RMSE[i,j+3]<- RMSE_mod_kr_v

    #results_RMSE_kr[i,3]<- res_mod_kr_v

    results_MAE[i,1]<- dates[i]  #storing the interpolation dates in the first column

    results_MAE[i,2]<- ns        #number of stations used in the training stage

    results_MAE[i,3]<- "MAE"

    results_MAE[i,j+3]<- MAE_mod_kr_v

    #results_RMSE_kr[i,3]<- res_mod_kr_v

    results_ME[i,1]<- dates[i]  #storing the interpolation dates in the first column

    results_ME[i,2]<- ns        #number of stations used in the training stage

    results_ME[i,3]<- "ME"

    results_ME[i,j+3]<- ME_mod_kr_v

    #results_RMSE_kr[i,3]<- res_mod_kr_v

    results_R2[i,1]<- dates[i]  #storing the interpolation dates in the first column

    results_R2[i,2]<- ns        #number of stations used in the training stage

    results_R2[i,3]<- "R2"

    results_R2[i,j+3]<- R2_mod_kr_v

    #results_RMSE_kr[i,3]<- res_mod_kr_v

    name3<-paste("res_kr_mod",j,sep="")

    #as.numeric(res_mod)

    #data_s[[name3]]<-res_mod_kr_s

    data_s[[name3]]<-as.numeric(res_mod_kr_s)

    #data_v[[name3]]<-res_mod_kr_v 

    data_v[[name3]]<-as.numeric(res_mod_kr_v)

    #Writing residuals from kriging

    data_name<-paste("mod",j,"_",dates[[i]],sep="")

    krig_raster_name<-paste("krmod_",data_name,out_prefix,".tif", sep="")

    writeGDAL(krmod,fname=krig_raster_name, driver="GTiff", type="Float32",options ="INTERLEAVE=PIXEL")

    krig_raster_name<-paste("krmod_",data_name,out_prefix,".rst", sep="")

    writeRaster(raster(krmod), filename=krig_raster_name)  #Writing the data in a raster file format...(IDRISI)

    #krig_raster_name<-paste("Kriged_tmax_",data_name,out_prefix,".tif", sep="")

    #writeGDAL(tmax_krige,fname=krig_raster_name, driver="GTiff", type="Float32",options ="INTERLEAVE=PIXEL")

    #X11()

    #plot(raster(co_kriged_surf))

    #title(paste("Tmax cokriging for date ",dates[[i]],sep=""))

    #savePlot(paste("Cokriged_tmax",data_name,out_prefix,".png", sep=""), type="png")

    #dev.off()

    #X11()

    #plot(raster(tmax_krige))

    #title(paste("Tmax Kriging for date ",dates[[i]],sep=""))

    #savePlot(paste("Kriged_res_",data_name,out_prefix,".png", sep=""), type="png")

    #dev.off()

    #

#   

#   cokrig1_dv<-predict(vm_g.fit,data_v)

#   cokrig1_ds<-predict(vm_g.fit,data_s)

# #   data_s$tmax_cokr<-cokrig1_ds$tmax.pred    

# #   data_v$tmax_cokr<-cokrig1_dv$tmax.pred

#   

#   #Calculate RMSE and then krig the residuals....!

#   

#   res_mod1<- data_v$tmax - data_v$tmax_kr              #Residuals from kriging.

#   res_mod2<- data_v$tmax - data_v$tmax_cokr            #Residuals from cokriging.

#   

#   RMSE_mod1 <- sqrt(sum(res_mod1^2,na.rm=TRUE)/(nv-sum(is.na(res_mod1))))                  #RMSE from kriged surface.

#   RMSE_mod2 <- sqrt(sum(res_mod2^2,na.rm=TRUE)/(nv-sum(is.na(res_mod2))))                  #RMSE from co-kriged surface.

#   #(nv-sum(is.na(res_mod2)))       

  #Saving the subset in a dataframe

  data_name<-paste("ghcn_v_",dates[[i]],sep="")

  assign(data_name,data_v)

  data_name<-paste("ghcn_s_",dates[[i]],sep="")

  assign(data_name,data_s)

#   results[i,2]<- ns     #number of stations in training

#   results[i,3]<- RMSE_mod1

#   results[i,4]<- RMSE_mod2  

#   

#   results_mod_n[i,1]<-dates[i]

#   results_mod_n[i,2]<-(nv-sum(is.na(res_mod1)))

#   results_mod_n[i,3]<-(nv-sum(is.na(res_mod2)))

## Plotting and saving diagnostic measures

results_table_MAE<-as.data.frame(results_MAE)

results_table_ME<-as.data.frame(results_ME)

results_table_R2<-as.data.frame(results_R2)

cname<-c("dates","ns","metric","krmod1", "krmod2","krmod3", "krmod4", "mkrod5")

colnames(results_table_RMSE)<-cname

colnames(results_table_MAE)<-cname

colnames(results_table_ME)<-cname

colnames(results_table_R2)<-cname

#Summary of diagnostic measures are stored in a data frame

tb_diagnostic1<-rbind(results_table_RMSE,results_table_MAE, results_table_ME, results_table_R2)   #

#tb_diagnostic1_kr<-rbind(results_table_RMSE_kr,results_table_MAE_kr, results_table_ME_kr, results_table_R2_kr)

#tb_diagnostic2<-rbind(results_table_AIC,results_table_GCV, results_table_DEV,results_table_RMSE_f)

write.table(tb_diagnostic1, file= paste(path,"/","results_GAM_Assessment_measure1",out_prefix,".txt",sep=""), sep=",")

#write.table(tb_diagnostic1_kr, file= paste(path,"/","results_GAM_Assessment_measure1_kr_",out_prefix,".txt",sep=""), sep=",")

#write.table(tb_diagnostic2, file= paste(path,"/","results_GAM_Assessment_measure2_",out_prefix,".txt",sep=""), sep=",")