plot3.R

## Getting full dataset
dataFull <- read.csv("./Data/household_power_consumption.txt", header=T, sep=';', na.strings="?", 
                      nrows=2075259, check.names=F, stringsAsFactors=F, comment.char="", quote='\"')
dataFull$Date <- as.Date(dataFull$Date, format="%d/%m/%Y")

## Subsetting the data
dataReal <- subset(dataFull, subset=(Date >= "2007-02-01" & Date <= "2007-02-02"))
rm(dataFull)

## Plot 3
with(dataReal, {
  plot(Sub_metering_1~Datetime, type="l",
       ylab="Energy sub metering", xlab="")
  lines(Sub_metering_2~Datetime,col='Red')
  lines(Sub_metering_3~Datetime,col='Blue')
})
legend("topright", col=c("black", "red", "blue"), lty=1, lwd=2, 
       legend=c("Sub_metering_1", "Sub_metering_2", "Sub_metering_3"))

## writing to file
dev.copy(png, file="plot3.png", height=504, width=504)
dev.off()