setwd("C:/Users/steven.aurousseau/Box Sync/Programming/Coursera - Data Science/4.0 Exploratory Data Analysis/Project1")

fileUrl <- "https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip"

download.file(fileUrl, destfile="householdPowerConsumption.zip", mode="wb")

unzip("householdPowerConsumption.zip")

file <- "household_power_consumption.txt"

housePower <- read.table(file, header=FALSE, sep=";",

na.strings="?",

skip=grep("1/2/2007", readLines(file)),

nrows=2879, # (2d * 24hr * 60min) - 1min = 2879mins

stringsAsFactors=FALSE)

housePower$time <- as.POSIXct(paste(housePower$V1, housePower$V2), format="%d/%m/%Y %H:%M:%S")

par(mfrow=c(2,2))

with(housePower, plot(time, V3, type="l", xlab="",

ylab="Global Active Power (kilowatts)"))

with(housePower, plot(time, V5, type="l",

xlab="datetime", ylab="Voltage"))

with(housePower, plot(time, V7, type="l", xlab="", ylab="Energy sub metering"))

with(housePower, lines(time, V8, col="red"))

with(housePower, lines(time, V9, col="blue"))

legend("topright",

c("Sub_metering_1", "Sub_metering_2", "Sub_metering_3"),

lty=c(1,1), col=c("black", "red", "blue"))

with(housePower, plot(time, V4, type="l",

xlab="datetime", ylab="Global_reactive_power"))

dev.copy(png, file="plot4.png")

dev.off()