Added lonlat selection

R/WFRTools.R

@@ -18,8 +18,8 @@ plotje <-function(data, title = " ") {
 #' @author Wietse Franssen \email{wietse.franssen@@wur.nl}
 #' @keywords internal
 #' @export
-ncPlot <-function(file, varName = NULL) {
-  data<-ncLoad(file, varName)
+ncPlot <-function(file, varName = NULL, lonlatbox = NULL) {
+  data<-ncLoad(file, varName, lonlatbox)
   plotje(data, title = paste0(data$Variable$varName, " (" ,data$Dates$start[1], ")"))
   title=paste0(data$Variable$longName, " [",data$Variable$units,"]\n(" ,data$Dates$start[1], ")")
   plotje(data, title = title)
@@ -63,8 +63,10 @@ ncCheck <-function(ncFile, variable) {
 }
 
 # @examples 
+# data <- ncLoad( file = paste0(find.package("WFRTools"),"./examples/data/example.nc4"))
 # data <- ncLoad( file = "./examples/data/example.nc4")
 # data <- ncLoad( file = "~/Desktop/gg/wfd_pr_1974.nc", varName = "pr")
+#find.package("WFRTools")
 #' ncLoad
 #' @description Loads a NetCDF file as a R-data structure
 #' @param file Name of the NetCDF file
@@ -74,9 +76,12 @@ ncCheck <-function(ncFile, variable) {
 #' @author Wietse Franssen \email{wietse.franssen@@wur.nl}
 #' @keywords internal
 #' @export
-ncLoad <-function(file, varName = NULL) {
+ncLoad <-function(file, varName = NULL, lonlatbox = NULL) {
   
+  ## first build an empty data structure
   data<-rDataStructure()
+  
+  ## Open the netcdf file
   ncFile <- nc_open( file )
   
   ## if no Variable is given then use the first one in the file
@@ -93,27 +98,34 @@ ncLoad <-function(file, varName = NULL) {
     }
   }
   
+  ## Do some sheck on the NetCDF file
   ncCheckResult<-ncCheck(ncFile = ncFile, variable = varName)
   
-  data$xyCoords$x <- ncFile$dim$lon$vals
-  data$xyCoords$y <- ncFile$dim$lat$vals
-
-  if (.PRINT_INFO == TRUE) {
-    cat("Variables:\n")
-    print(names(ncFile$var))
-    print(ncCheckResult)
+  ## Fill lon and lat
+  if (is.null(lonlatbox)) { 
+    LonIdx <- c(1: ncFile$dim$lon$len)
+    LatIdx <- c(1: ncFile$dim$lat$len)
+  } else {
+#    LonIdx <- which( ncFile$dim$lon$vals > lonlatbox[1] | ncFile$dim$lon$vals < lonlatbox[2])
+    LonIdx <- which( ncFile$dim$lon$vals > lonlatbox[1] & ncFile$dim$lon$vals < lonlatbox[2])
+    LatIdx <- which( ncFile$dim$lat$vals > lonlatbox[3] & ncFile$dim$lat$vals < lonlatbox[4])
   }
-    
+  data$xyCoords$x <- ncFile$dim$lon$vals[LonIdx]
+  data$xyCoords$y <- ncFile$dim$lat$vals[LatIdx]
+  
+  #data <- ncvar_get( ncFile, "pr")[ LonIdx, LatIdx, 1]
+  ## Fill time
   NCtime          <- ncvar_get( ncFile, "time" ) 
   NCtimeAtt       <- ncatt_get( ncFile, "time", "units" )$value
-  
   firstTime<-unlist(strsplit(NCtimeAtt, split=' ', fixed=TRUE))[3]
   firstTime<-strptime(firstTime, format = "%Y-%m-%d", tz = "GMT")
-
   data$Dates$start <- format(firstTime + (86400 * (NCtime+0)), format="%Y-%m-%d %T %Z")
   data$Dates$end   <- format(firstTime + (86400 * (NCtime+1)), format="%Y-%m-%d %T %Z")
   
-  data$Data <- ncvar_get( ncFile, varName ) 
+  ## Fill data
+  #data <- ncvar_get( ncFile, "pr")[ LonIdx, LatIdx, 1]
+  data$Data <- ncvar_get( ncFile, varName ) [ LonIdx, LatIdx, ]
+  #data$Data <- ncvar_get( ncFile, varName ) 
   attr(data$Data,"dimensions") <- ncCheckResult$dims
   data$Variable$varName  <- varName
   
@@ -130,10 +142,30 @@ ncLoad <-function(file, varName = NULL) {
   } else {
     data$Variable$units <- "missing"
   }
+  
+  ## Close the file
   nc_close(ncFile)
+  
+  ## Print some info
+  if (.PRINT_INFO == TRUE) {
+    cat("Variables:\n")
+    print(names(ncFile$var))
+    print(ncCheckResult)
+  }
+  
   return(data)
 }
 
+
+
+
+
+
+
+
+
+
+
 # rm(list=ls())
   # library(ncdf4)
   # library(fields) # e.g: using the fields library

man/ncLoad.Rd

@@ -4,7 +4,7 @@
 \alias{ncLoad}
 \title{ncLoad}
 \usage{
-ncLoad(file, varName = NULL)
+ncLoad(file, varName = NULL, lonlatbox = NULL)
 }
 \arguments{
 \item{file}{Name of the NetCDF file}

man/ncPlot.Rd

@@ -4,7 +4,7 @@
 \alias{ncPlot}
 \title{Make a image of the NetCDF data}
 \usage{
-ncPlot(file, varName = NULL)
+ncPlot(file, varName = NULL, lonlatbox = NULL)
 }
 \value{
 Nothing