plot1.R

plot1 <- function(){
    
    ## Read in the data from the data set the separator is specified as ; and the
    ## NA values are defined as ?
    data<-read.table("household_power_consumption.txt",header=TRUE, sep=";", na.strings="?")
    
    ## Merge time and date together and convert to timestamp
    data$timestamp<-strptime(paste(data$Date,data$Time), format="%d/%m/%Y%H:%M:%S")
    
    
    ## Subset the data to chose only the two days of interest
    data <- subset(data, timestamp >= "2007-02-01" & timestamp <= "2007-02-02")
    
    ## Open the PNG device to write write the graph into
    png(filename = "plot1.png", width = 480, height = 480, units = "px")
    
    ## Create the histogram with
    hist(data$Global_active_power, col = "red", main="Global Active Power", xlab="Global Active Power (kilowatts)")
    
    ## Close the device and return to standard device
    dev.off()
    

    
}