plot2.R

require(data.table)
household_power_consumption <- fread("household_power_consumption.txt", header = TRUE, sep = ";", data.table = TRUE, na.strings = "?", stringsAsFactors = FALSE)
household_power_consumption <- household_power_consumption[,DateTime:=paste(Date, Time)]
household_power_consumption$Date <- as.Date(x = household_power_consumption$Date, format = "%d/%m/%Y")
household_power_consumption_filtered <- household_power_consumption[Date %between% c(as.Date("2007-02-01"), as.Date("2007-02-02")),]
household_power_consumption_filtered <- household_power_consumption_filtered[, Global_active_power:=as.numeric(Global_active_power)]
household_power_consumption_filtered <- as.data.frame(household_power_consumption_filtered) 
household_power_consumption_filtered$Real_DateTime <- strptime(household_power_consumption_filtered$DateTime, format = "%d/%m/%Y %H:%M:%S")
with(household_power_consumption_filtered, plot(Real_DateTime, Global_active_power, type = "l", xlab = "", main = "", ylab = "Global Active Power (kilowatts)", cex.lab = 0.7, cex.axis = 0.7))
dev.copy(png, file="plot2.png")
dev.off()