import_giss_data.R

srctxt <- "http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt"

# Import as a character vector first so can get info about length etc.
aslines <- readLines(srctxt)

# Store the first occurrence of the header row as a character vector
header <- strsplit(aslines[8], "\\s+")[[1]]

# Count the lines of data (any lines starting with 4 digits)
nlines <- length(grep("^\\d{4}", aslines))

# Read the table
tbl <- read.table(srctxt, header = FALSE, skip = 7, nrows = nlines, 
                  comment.char = "Y", na.strings = c("***", "****"), 
                  colClasses = c(rep("numeric", 19), "NULL"), col.names = header)

# Set the column headings of Annual Mean columns
names(tbl)[c(14,15)] <- paste0("AnnMean_", names(tbl)[c(14,15)])