library(sqldf)

## setwd

#wd <- "##Path to working directory"

#curwd <- getwd()

#if ( wd != curwd ) {

# setwd(wd)

#}

#######################################

## TXT file was too big for GitHub so I only added the ZIP. This line does some

## initial setup to unzip the file and place it in the ./data directory before proceeding.

unzip("./data/household_power_consumption.txt.zip", files="household_power_consumption.txt", exdir="./data")

## read table

cols <- c("character", "character", rep("numeric", 7))

sql <- "SELECT * FROM file WHERE Date='1/2/2007' OR Date='2/2/2007'"

householdData <- read.csv.sql("./data/household_power_consumption.txt", sql = sql, header = TRUE, sep=";", colClasses = cols)

dataSample <- householdData

dateTime <- paste( dataSample$Date, dataSample$Time, sep = " " )

dateTime <- strptime( dateTime, format = "%d/%m/%Y %H:%M:%S" )

dataSample <- cbind( dataSample, dateTime )

names(dataSample) <- colNames <- c("Date", "Time", "GlobalActivePower", "GlobalReactivePower", "Voltage", "GlobalIntensity", "SubMetering1", "SubMetering2", "SubMetering3", "DateTime")

## Create plot3.png

png("plot3.png", width=480, height=480, bg="transparent")

plot(dataSample$DateTime, dataSample$SubMetering1, type="l", xlab="", ylab="Energy sub metering")

lines(dataSample$DateTime, dataSample$SubMetering2, type="l", col="red")

lines(dataSample$DateTime, dataSample$SubMetering3, type="l", col="blue")

legend("topright", legend=c("Sub_metering_1", "Sub_metering_2", "Sub_metering_3"), lwd="1", col=c("black", "red", "blue"))

dev.off()