plot3.R

## Getting full dataset
  data_full <- read.csv("./household_power_consumption.txt", header=T, sep=';', na.strings="?", 
                                            nrows=2075259, check.names=F, stringsAsFactors=F, comment.char="", quote='\"')
  data_full$Date <- as.Date(data_full$Date, format="%d/%m/%Y")
  
    ## Subsetting the data
    data <- subset(data_full, subset=(Date >= "2007-02-01" & Date <= "2007-02-02"))
    rm(data_full)
    
    ## Converting dates
      datetime <- paste(as.Date(data$Date), data$Time)
      data$Datetime <- as.POSIXct(datetime)
    
        ## Plot 3
        with(
          data, {
              plot(Sub_metering_1~Datetime, type="l", ylab="Global Active Power (kilowatts)", 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"))
      
        ## Saving to file
      dev.copy(png, file="plot3.png", height=480, width=480)
      dev.off()