R/read123.R

In steingod/R-mipolsat: Useful functions for handling locally processed satellite data

#
# NAME:
# readsig
#
# PURPOSE:
# To read collocate HDF5 files containing validation data for signature
# studies.
#
# NOTES:
# Not fully finished... 
#
# BUGS:
# Probably in the underlying C-function...
# C functions does not transfer strings back properly...
#
# AUTHOR:
# Øystein Godøy, MET/FOU, 30.01.2003
#
# MODIFIED:
# Øystein Godøy, met.no/FOU, 12.10.2004 
# Reduce the number of vectors to read in order to be able to handle data
# within memory bounds.
# Øystein Godøy, METNO/FOU, 2013-04-11 
#
# CVS_ID:
# $Id: read123.R,v 1.4 2013-05-27 13:14:20 steingod Exp $
#

read123 <- function(filename,classname="cloud",station="NA",start="NA",end="NA") {

    if (missing(filename)) {
        cat("Husk at filnavn må oppgis...\n")
        return;
    }

    start <- as.POSIXct(strptime(start,format="%d%b%Y"))
    end <- as.POSIXct(strptime(end,format="%d%b%Y"))
    if (is.na(start)) start <- 0
    if (is.na(end)) end <- 0

    noobs <- 0

    cat("Checking number of records in the file...\n")
    tmp <- .C("checkrec",
              filename=as.character(filename),
              noobs=as.integer(noobs),
              classname=as.character(classname),
              station=as.character(station),
              start=as.integer(start),end=as.integer(end),package="mipolsat")
    cat(paste("Number of records found:",tmp$noobs,"\n"))
    if (tmp$noobs <= 0) {
        return(cat("Bailing out...\n"))
    }

    nopix <- 13*13
    size <- tmp$noobs*nopix
    tid <- vector(mode="integer",length=size)
    stid <- vector(mode="integer",length=size)
    N <- vector(mode="integer",length=size)
    E <- vector(mode="integer",length=size)
    sss <- vector(mode="integer",length=size)
    k1 <- real(length=size)
    k2 <- real(length=size)
    k3a <- real(length=size)
    k3b <- real(length=size)
    k4 <- real(length=size)
    k5 <- real(length=size)
    soz <- real(length=size)
    saz <- real(length=size)
    raz <- real(length=size)
    cat("\nThe necessary vectors are allocated...\n")

    cat("Reading data...\n")
    tmp <- .C("Rread123",
              filename=as.character(filename),
              noobs=as.integer(tmp$noobs),nopix=as.integer(nopix),
              classname=as.character(classname),
              station=as.character(station),
              start=as.integer(start),end=as.integer(end),
              stid=as.integer(stid),tid=as.integer(tid),
              N=as.integer(N),
              E=as.integer(E), sss=as.integer(sss),
              k1=as.real(k1), k2=as.real(k2), k3a=as.real(k3a),
              k3b=as.real(k3b),
              k4=as.real(k4), k5=as.real(k5), 
              soz=as.real(soz), saz=as.real(saz), raz=as.real(raz),
              package="mipolsat"
              )

    tmp$tid <- ISOdate(1970,1,1)+tmp$tid 
    tmp$k1[tmp$k1 < -100] <- NA
    tmp$k2[tmp$k2 < -100] <- NA
    tmp$k3a[tmp$k3a < -100] <- NA
    tmp$k3b[tmp$k3b < -100] <- NA
    tmp$k4[tmp$k4 < -100] <- NA
    tmp$k5[tmp$k5 < -100] <- NA
    tmp$soz[tmp$soz < -100] <- NA
    tmp$saz[tmp$saz < -100] <- NA
    tmp$raz[tmp$raz < -100] <- NA
    tmp$N[tmp$N < 0] <- NA
    tmp$E[tmp$E < 0] <- NA
    tmp$sss[tmp$sss < 0] <- NA
    return(tmp)
}