plot1.R

# Course Progect1 Explanatory Data Analysis

## Download and unzip data file
fileURL <- "https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip"
download.file(fileURL, destfile = "CourseProject1.zip")
unzip("CourseProject1.zip")

## Read table
housepowerdata<- read.table("household_power_consumption.txt", header = TRUE, nrows = 70000,
                            sep =";" ,stringsAsFactors = FALSE , colClasses = rep("character",9) 
                            , na.strings = c("?"))
housepowerdata[,1] <- as.Date(housepowerdata[,1], "%d/%m/%Y")  

## Copy data when dates between 1 and 2 febr 2007
selecteddaydata <- housepowerdata[housepowerdata[,1] >= "2007-02-01" & housepowerdata[,1] <= "2007-02-02", ]


png(filename = "plot1.png",    width = 480, height = 480,)
hist(as.numeric(selecteddaydata$Global_active_power), col="red", main = "Glabal Active Power",
     xlab = "Global Active Power (kilowatts)" )

dev.off()