############## RClimate Script: Mauna Loa Monthly CO2    ###################################
## Script stored on http://chartsgraphs.wordpress.com account for Users to source()       ##                                                                                       ## 
## Download and process Monthly CO2 Data File                                             ##
## Developed by D Kelly O'Day to demonstrate use of source() function for climate data    ##
##                   http:chartsgraphs.wordpress.com    1/16/10                           ##
############################################################################################
  library(plyr); library(reshape); par(las=1); par(ps=10)
  par(oma=c(2.5,1,1,1)); par(mar=c(2.5,4,2,1))

## STEP 1: SETUP
   link <-url("ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt")
## STEP 2: READ DATA
   CO2_data <- read.table(link,
             sep = "", row.names = NULL,header = F,colClasses = rep("numeric", 7),
             comment.char = "#", na.strings = -99.99)
  names(CO2_data) <- c("Yr", "Mo", "Mo_Yr", "CO2", "Trnd", "X", "dys")
  with(CO2_data,{
## STEP 3: Determine Month, Year for last reading
   c <- nrow(CO2_data)                    # Find number of data rows
    mo <- Mo[c]                           # Find last month of data
    yr <- Yr[c]                           # Find last year od data
    lco2 <- CO2[c]                         # Find last CO2 reading
## STEP 4: CREATE PLOT
######        Set Chart Parameters
      par(las=1);par(ps = c(10));par(pin = c(6,3))
      par(oma=c(2.5,1,3,1)); par(mar=c(2,4,0,0))
### Make Basic Plot
  plot(CO2 ~ Mo_Yr, CO2_data,
         ylim = c(300,400),
         xlim = c(1958, yr+2),
         type="l", xaxs = "i", yaxs="i",
         col = "grey", cex.main=1, cex.axis = .8, cex.lab = .8,
         xlab = "",
         ylab = expression(paste(CO[2] - ppmv)))
### Add last point & Yr - month note
   points(Mo_Yr[c], lco2, type = "p",pch=16, col = "red")
   points(1959, 395, type = "p",pch=16, col = "red")
   text(1960, 303, "Source NOAA:ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt",
          adj=0, cex = 0.8)
## Plot Annotation
    mo_names <- c("Jan", "Feb", "Mar", "Apr", "May", "June", "July", "Aug", "Sept",  "Oct", "Nov", "Dec")
    thru <-   paste(mo_names[mo],",",yr, "- ", lco2, " ppmv")   # Note on last data point
    text(1960,395, thru, cex=0.8, adj=0)
    Title <- expression(paste("C", O[2], " (ppmv)Trends Since 1958, Mauna Loa, Hawaii"))
   mtext(Title, 3,2, outer = TRUE)
   mtext(paste("Data Updated Through ", mo_names[mo], ",", yr), 3,1, outer = TRUE, cex = 0.85)
   mtext("D Kelly O'Day - http://chartgraphs.wordpress.com", 1,1, adj = 0, cex = 0.8, outer=TRUE)
   mtext(format(Sys.time(), "%m/%d/ %Y"), 1, 1, adj = 1, cex = 0.8, outer=TRUE)

})
closeAllConnections()