plot2.R

########################################################
# Assignment course 4,  Week 1, plot 2
########################################################


# Downloading data:

if (!file.exists("raw_data.zip")){
  fileURL <- "https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip"
  download.file(fileURL, "raw_data.zip", method="curl")
}  
if (!file.exists("household_power_consumption.txt")) { 
  unzip("raw_data.zip") 
}

# extract data o
f February first and second
names <- c("Date", "Time", "Global_active_power", "Global_reactive_power", "Voltage", "Global_intensity", "Sub_metering_1", "Sub_metering_2", "Sub_metering_3")
data <-  read.table( "household_power_consumption.txt", nrows=2881, skip=66637, sep=";", col.names = names ) 

# Creating a new column of the full date and converting its type
data$fullDate <- apply(select(data, c("Date", "Time")), MARGIN = 1, function(x){paste(x[1], x[2])})
data$fullDate <- strptime(data$fullDate, format = "%d/%m/%Y %H:%M:%S")

#plot 2: 
Sys.setlocale("LC_ALL", "English")  # changing the local language to English, since the days were first in french
with(data, plot(x=fullDate, y=Global_active_power, type="l", main="",xlab="",  ylab= "Global Active Power (kilowatts)" ))

# save the plot to a png file
png(filename = "plot2.png",width = 480, height = 480)
with(data, plot(x=fullDate, y=Global_active_power, type="l", main="",xlab="",  ylab= "Global Active Power (kilowatts)" ))
dev.off()