plot4.R

## Create Plot 4
par(
  mfrow = c(2, 2),
  mar = c(4, 4, 2, 1),
  oma = c(0, 0, 2, 0)
)
with(t, {
  plot(
    Global_active_power ~ dateTime,
    type = "l",
    ylab = "Global Active Power (kilowatts)",
    xlab = ""
  )
  plot(Voltage ~ dateTime,
       type = "l",
       ylab = "Voltage (volt)",
       xlab = "")
  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,
    bty = "n",
    legend = c("Sub_metering_1", "Sub_metering_2", "Sub_metering_3")
  )
  plot(
    Global_reactive_power ~ dateTime,
    type = "l",
    ylab = "Global Rective Power (kilowatts)",
    xlab = ""
  )
})

## Saving to file
dev.copy(png,
         file = "plot4.png",
         height = 480,
         width = 480)
dev.off()