########################################################################################
# script to plot total solar uv irradiance between wavelength 116nm - 310nm
# solar uv from SORCE
# http://lasp.colorado.edu/sorce/ssi_data/
# 8 Nov 2011
# Joseph Wheatley
# www.joewheatley.net
########################################################################################

require(ggplot2)

file.in <- "http://lasp.colorado.edu/sorce/ssi_data/solstice/fuv/txt/sorce_fuv_latest.txt.zip"
download.file(file.in, "temp.txt.zip")
file.in <- unzip("temp.txt.zip")
uvF <- read.table(file.in, skip=79,header=F)
names(uvF) <- c("date","date_julian","wave_min","wave_max","mode","version","irradiance","error","quality")

file.in <- "http://lasp.colorado.edu/sorce/ssi_data/solstice/muv/txt/sorce_muv_latest.txt.zip"
download.file(file.in, "temp.txt.zip")
file.in <- unzip("temp.txt.zip")
uvM <- read.table(file.in, skip=79,header=F)
names(uvM) <- c("date","date_julian","wave_min","wave_max","mode","version","irradiance","error","quality")
#clean up
unlink(file.in)
unlink("temp.txt.zip")
#merge data
uvF <- subset(uvF, select=c(date,wave_max,irradiance))
uvM <- subset(uvM, select=c(date,wave_max,irradiance))
uv <- merge(uvF,uvM, all=T)

uv$year <- substr(uv$date,1,4)
uv$month <- substr(uv$date,5,6)
uv$day <- substr(uv$date,7,8)

dates <- as.Date(paste(uv$year,uv$month,uv$day,sep="-"))
uv$date <- dates
uv$year <- NULL
uv$month <- NULL
uv$day <- NULL

#switch to wide format
uv.wide <- cast(uv,date~wave_max, value="irradiance")
uv.wide <- data.frame(uv.wide)
nDate <- length(uv.wide$date)

#total uv irradiance
uv.wide$total <- sapply(1:nDate,function(d) sum(unlist(uv.wide[d,])[-1]))
#total irradiance dataframe
uv.tot <- data.frame(dates=uv.wide$date,uvtotal=uv.wide$total)

g <- ggplot(uv.tot, aes(dates,uvtotal)) + geom_point(aes(colour="115-310nm"))+scale_colour_discrete("")
g <- g +stat_smooth(colour="grey50",method="loess",span=0.5,size=1)
g <- g + opts(title=expression(paste("solar UV irradiance (", Wm^{-2}, ")", sep = "")))+xlab("") + ylab("")
#g <- g+ geom_text(aes(x,y,label=text), data.frame(x=uv.tot$dates[1000],y=19.3,text="data:lasp.colorado.edu/sorce/data/ssi_data.htm"),size=4)
print(g)