plot4.R

setwd("C:/Users/samsung/Documents/Data_Science/Material/Explain_data/Assignment1")

PowerConsumption <- read.table("./household_power_consumption.txt",nrow= 300000, header=TRUE, sep=";", na.strings = "?")

dates <- PowerConsumption$Date
time <- PowerConsumption$Time

datetime <- paste(dates, time)

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

PowerConsumption <- PowerConsumption[,-1]
PowerConsumption <- PowerConsumption[,-1]

PowerConsumption <- cbind(datetime, PowerConsumption)

my.data.frame <- subset(PowerConsumption, PowerConsumption$datetime > strptime("2007-01-31 24:00:00", format="%Y-%m-%d %H:%M:%S") & PowerConsumption$datetime < strptime("2007-02-03 00:00:00", format="%Y-%m-%d %H:%M:%S"))

png(filename='./plot4.png',width=480,height=480,units='px')

par(mfrow=c(2,2))

#left quadrant first chart
plot(my.data.frame$datetime,my.data.frame$Global_active_power,ylab='Global Active Power',xlab='',type='l')
#right quadrant second chart
plot(my.data.frame$datetime,my.data.frame$Voltage,xlab='datetime',ylab='Voltage',type='l')

#left quadrant third chart
lncol<-c('black','red','blue')
lbls<-c('Sub_metering_1','Sub_metering_2','Sub_metering_3')
plot(my.data.frame$datetime,my.data.frame$Sub_metering_1,type='l',col=lncol[1],xlab='',ylab='Energy sub metering')
lines(my.data.frame$datetime,my.data.frame$Sub_metering_2,col=lncol[2])
lines(my.data.frame$datetime,my.data.frame$Sub_metering_3,col=lncol[3])
legend('topright',legend=lbls,col=lncol,lty='solid')


#right quadrant fourth chart
plot(my.data.frame$datetime,my.data.frame$Global_reactive_power,xlab='datetime',ylab='Global_reactive_power',type='l')
x<-dev.off()