library(ggplot2)
library(scales)

epw = "/home/martin/weather-datasets/GBR_London-Heathrow.AP.2003.baseline_CIBSETM49.epw"
idf = "/home/martin/pyidf/Minimal.idf"
system(paste("energyplus -r -a -w ",epw," ",idf))
EPO = read.csv("eplusout.csv")		
names(EPO)<-c("DT","SOLAR")
EPO$DT = as.POSIXlt(EPO$DT,format="%m/%d %H:%M:%S") 	
EPO$HR = as.numeric(format(EPO$DT, "%H"))

p = ggplot(EPO,aes(x = DT, y = HR, color = SOLAR))+layer(geom = "point")+
        scale_y_reverse(expand = c(0,0),breaks = c(0:24),
                                                labels=c(
                                                   "0","","","3","","","6","","",
                                                   "9","","","12","","","15","","",
                                                   "18","","","21","","","24"),
                                                limits = c(24,0))+
scale_x_datetime(breaks = "1 month",expand = c(0,0),labels = date_format("%^b"))+
scale_colour_gradient(limits=c(0, 800),low="white", high="black")+
        theme(
                panel.background = element_rect(fill = 'white'),        # fill background white
                panel.border = element_rect(fill=NA,colour = "#AAAAAA",size=2),   # set size and colour of panel border
                panel.grid.major = element_line(colour = "#B0B0B0"),    # change grid line colour
                panel.grid.minor.x = element_blank(),   # remove x-axis minor gridlines
                axis.text = element_text(size=10, colour = "#505050"),  # set size and colour of axis text
                axis.title.x = element_text(vjust=-3,size=10),  # set position of x-axis title text
                axis.title.y = element_text(vjust=+3,size=10))   # set position of y-axis title text
png(file = "myplot.png", bg = "transparent",width = 1000, height = 480)
p
dev.off()