Date1 <- strptime("01/02/2007","%d/%m/%Y") # first date in data to analyse

Date2 <- strptime("02/02/2007","%d/%m/%Y") # second date in data to analyse

## Read whole data

data <- read.csv2("household_power_consumption.txt",

stringsAsFactors = FALSE,

na.strings = "?")

## use only data for specified dates

data <- data[strptime(data$Date, "%d/%m/%Y") == Date1 |

strptime(data$Date, "%d/%m/%Y") == Date2,]

## In order to use a combination of date and time

## (there are only two days, so date alone wouldn't produce sufficient data')

## we use a combination of date and time

## first convert character to date ...

data$Date <- strptime(data$Date, "%d/%m/%Y")

## ... then add time to it (using strptime does not work), creating a new combination Moments

data$Moments <- as.POSIXct(paste(data$Date, data$Time))

png("plot3.png", width=480, height= 480) ## open png device

plot(data$Moments, # Date-and-Time-Kombinatiomn

data$Sub_metering_1, # Data to plot

type= "n", # draw frame only, no data

ylab= "Energy sub metering", # y-axis text

xlab="") # no x-axis text

points(data$Moments,

data$Sub_metering_1, # actual data

type= "l", # plottinng lines

col="black") # black color

points(data$Moments,

data$Sub_metering_2, # actual data

type= "l", # plotting lines

col="red") # red color

points(data$Moments,

data$Sub_metering_3, # actual data

type= "l", # plotting lines

col="blue") # blue color

legend("topright",

c("Sub_metering_1","Sub_metering_2","Sub_metering_3"), # legend texts

lty=c(1,1,1), # lines

lwd=c(2.5,2.5,2.5), # line length

col=c("black","red","blue")) # line colors

dev.off() ## close device