plot3.r

#Plot3
#Exploratory Data Analysis
#Joseph Chatman

#retrieve data
data.source <- read.table("household_power_consumption.txt", comment.char= "", sep= ";", na.strings= "?", skip= 66600, n= 3050)
#convert data into a data frame
data <- data.frame(data.source)
#subset for dates required
segment<- subset(data, as.Date(V1) == '01/02/2007' | as.Date(V1) == '02/02/2007')

#conversions on the date and time 
date <- as.character(segment$V1)
time <- as.character(segment$V2)
date.time <- paste(date, time)
date.time <- strptime(date.time, "%d/ %m/ %Y %H: %M: %S")

#create the plot and add sub_metering_1 - 3
png(file = 'plot3.png')#open PNG device and create plot3.PNG
plot (date.time,segment$V7,type = "l", xlab = "", ylab = "Energy sub metering", col = "black")
lines (date.time,segment$V8,type = "l", col = "red")
lines (date.time,segment$V9,type = "l", col = "blue")

legend("topright", lty = 1, col = c("black", "red", "blue"), legend = c("Sub_metering_1","Sub_metering_2", "Sub_metering_3"))
dev.off()#close PNG device in my working directory