plot4.R

#Importing data
my_dbset <- read.table("household_power_consumption.txt", sep = ";", header = TRUE, na.strings = "?")
#Subsetting
my_subset <- my_dbset[my_dbset$Date == "1/2/2007" | my_dbset$Date == "2/2/2007",]
#Re-formatting the subset
my_subset$Time <- strptime(paste(my_subset$Date, my_subset$Time), "%d/%m/%Y %H:%M:%S")
my_subset$Date <- as.Date(my_subset$Date, "%d/%m/%Y")
#Plotting
par(mfrow = c(2,2))
plot(my_subset$Time,my_subset$Global_active_power, type="l",xlab = "", ylab="Global Active Power (kW)")
plot(my_subset$Time,my_subset$Voltage, type="l", xlab="datetime", ylab="Voltage")
plot(my_subset$Time,my_subset$Sub_metering_1,type="l",col = "black", xlab = "", ylab="Energy Sub Metering")
lines(my_subset$Time,my_subset$Sub_metering_2, col = "red")
lines(my_subset$Time,my_subset$Sub_metering_3, col = "blue")
legend("topright", col=c("black","red","blue"), c("Sub_metering_1","Sub_metering_2", "Sub_metering_3"),lty=c(1,1), lwd=c(1,1))
plot(my_subset$Time,my_subset$Global_reactive_power, type="l", xlab="datetime", ylab="Global_reactive_power")
#Making the png
dev.copy(png, file="plot4.png", width=480, height=480)
#Closing the device
dev.off()