temperature <- read.table("~/LaptopShare/Teaching/s215b.S04/UStemp.dat",sep="\t",header=T)


library(maps)

# blue to green to red palette

pseudoPalette <-function (low = "white", high = c("green", "red"), mid = NULL,
                      k = 50)
{
    low <- col2rgb(low)/255
    high <- col2rgb(high)/255
    if (is.null(mid)) {
      r <- seq(low[1], high[1], len = k)
      g <- seq(low[2], high[2], len = k)
      b <- seq(low[3], high[3], len = k)
    }
    if (!is.null(mid)) {
        k2 <- round(k/2)
        mid <- col2rgb(mid)/255
        r <- c(seq(low[1], mid[1], len = k2), seq(mid[1], high[1],
            len = k2))
        g <- c(seq(low[2], mid[2], len = k2), seq(mid[2], high[2],
            len = k2))
        b <- c(seq(low[3], mid[3], len = k2), seq(mid[3], high[3],
            len = k2))
    }
    rgb(r, g, b)
  }


# a color bar for legend
pseudoColorBar <- function (x, horizontal = TRUE, col = heat.colors(50), scale = 1:length(x),
    k = 11, log.ticks=FALSE,...)
{
    if (is.numeric(x)) {
        x <- x
        colmap <- col
    }
    else {
      colmap <- x
      low <- range(scale)[1]
      high <- range(scale)[2]
      x <- seq(low, high, length = length(x))
    }
    if (length(x) > k){
      x.small <- seq(x[1], x[length(x)], length = k)
      if (log.ticks){
        x.small <- sign(x.small)*(2^abs(x.small) -1)
        x <- sign(x)*(2^abs(x) -1)
      }
    }
    else{
      x.small <- x
      if (log.ticks){
        x.small <- sign(x.small)*(2^abs(x.small) -1)
        x <- sign(x)*(2^abs(x) -1)
      }
    }
    if (horizontal) {
        image(x, 1, matrix(x, length(x), 1), axes = FALSE, xlab = "",
            ylab = "", col = colmap, ...)
        axis(1, at = rev(x.small), labels = signif(rev(x.small),
            2), srt = 270)
    }
    if (!horizontal) {
      image(1, x, matrix(x, 1, length(x)), axes = FALSE, xlab = "",
            ylab = "", col = colmap, ...)
      par(las = 1)
      axis(4, at = rev(x.small), labels = signif(rev(x.small),2))
      par(las = 0)
    }
    box()
}

map.palette <- pseudoPalette(low="blue",high="yellow",mid="orange",k=80)

# need each temperature to map into a color

temperature.colors <- map.palette[trunc((temperature$JanTemp + abs(min(temperature$JanTemp)) +1)/(range(temperature$JanTemp)[2] - range(temperature$JanTemp)[1] +1)*80)]


png("TempDist1.png",height=800,width=1024)
layout(matrix(c(1, 2), 1, 2), width = c(9, 1))
par(mar = c(4, 4, 5, 3))
plot(-temperature$Long,temperature$Lat,pch=20,col=temperature.colors,cex=4,xlab="Longitude",ylab="Latitude",main="Mean January Minimum Temperatures")
map("usa",add=T)
par(mar = c(4, 0, 5, 3))
pseudoColorBar(-10:65,horizontal=F,col=map.palette)
layout(1)
par(mar = c(5, 4, 4, 2) + 0.1)
dev.off()