plot3.R

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### Plot3.R
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### For course project 1
### Exploratory Data Analysis --- Coursera
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### Read in the relevant dates - Feb 1,2 2007
raw_data <- read.table("household_power_consumption.txt", header=TRUE,sep =";")
data <- [raw_data$Date == "1/2/2007" | raw_data$Date == "2/2/2007",]

### open file
png(file = "plot3.png")

### create plot
# First get relevant data in relevant form
Sub1 <- as.numeric(as.character(data$Sub_metering_1))
Sub2 <- as.numeric(as.character(data$Sub_metering_2))
Sub3 <- as.numeric(as.character(data$Sub_metering_3))

raw_dt <- paste(data$Date,data$Time)
posix_dt <- strptime(raw_dt, "%d/%m/%Y %H:%M:%S")


###now make the plot (emtpy)
plot(posix_dt, Sub1, type = "n", xaxt = "n", xlab="", ylab="Energy sub metering")
# get the x-axis right
r <- as.POSIXct(round(range(posix_dt), "hours"))
axis.POSIXct(1,at=seq(r[1],r[2], by="day"), format = "%a")
# add the three different data sets
points(posix_dt,Sub1,type="l",col="black")
points(posix_dt,Sub2,type="l",col="orange")
points(posix_dt,Sub3,type="l",col="blue")
#add the legend
legend("topright",c("Sub_metering_1", "Sub_metering_2","Sub_metering_3"), lty=c(1,1,1), lwd=c(2.5,2.5,2.5),col=c("black","orange","blue"))



### close file
dev.off()