plot3.R

temp <- tempfile()
download.file('http://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip',temp)
all_data<-read.csv(unzip(temp),sep = ";",header = T,quote = "",na.strings='?')
unlink(temp)
my_data<-subset(all_data,Date=='1/2/2007' | Date=='2/2/2007')
my_data$dt<-strptime(paste(my_data$Date,my_data$Time),"%d/%m/%Y %T")
png('plot3.png',bg = "transparent")
plot(my_data$dt,my_data$Sub_metering_1,ylab='Energy Submetering',xlab='',t='n')
lines(my_data$dt,my_data$Sub_metering_1,col='black')
lines(my_data$dt,my_data$Sub_metering_2,col='red')
lines(my_data$dt,my_data$Sub_metering_3,col='blue')
legend('topright',col=c("black","red","blue"),legend = c("Sub_metering_1","Sub_metering_2","Sub_metering_3"),lwd=1)
dev.off()