plot4.R

source("load_data.R")

png(file="plot4.png", width=480, height=480)

par(mfrow = c(2,2))

with(subconsumption, {
  plot(DateTime, Global_active_power, type="l", ylab="Global Active Power")
  
  plot(DateTime, Voltage, type="l", ylab="Voltage")
 
  plot(DateTime, Sub_metering_1, type="l", ylab="Energy sub metering", xlab="")
  lines(DateTime, Sub_metering_2, col="red")
  lines(DateTime, Sub_metering_3, col="blue")
  legend("topright", lty=c(1,1,1), bty="n", legend=c("Sub_metering_1", "Sub_metering_2", "Sub_metering_3"),
         col= c("black", "red", "blue"))
  
  plot(DateTime, Global_reactive_power, type="l")
  
})

dev.off()