# Download and read household power consumption data

url <- "http://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip"

temp <- tempfile()

download.file(url, temp)

data <- read.table(unz(temp, "household_power_consumption.txt"), header=T, sep=";", na.strings="?")

unlink(temp)

# Cleaning data

data[,1] <- as.Date(data[,1], format="%d/%m/%Y")

data <- data[data$Date == "2007-02-01" | data$Date == "2007-02-02",]

data[,2] <- format(strptime(data[,2], format="%H:%M:%S"), format="%H:%M:%S")

for(i in 3:8){

data[,i] <- as.numeric(as.character(data[,i]))

}

# Create and save Global Active Power scatterplot

png(file="plot2.png")

plot(data[,3], type="l", ylab="Global Active Power (kilowatts)", xlab="", axes=F)

axis(1, at=1440*0:2, lab=c("Thu","Fri","Sat"))

axis(2, at=2*0:3)

box()

dev.off();