#Exploratory Data Analysis Project 1, plot 1.

# set working dirctory to the folder where data file resides.

setwd("C:/coursera/exdata_data_household_power_consumption")

# Get total data

data_file <- "household_power_consumption.txt"

total_data <- read.table(data_file, header=TRUE, sep=";", na.strings="?", stringsAsFactors=FALSE, dec=".")

#Get subset data

subset_data <- total_data[total_data$Date %in% c("1/2/2007","2/2/2007") ,]

#Create plot

global_active_power <- as.numeric(subset_data$Global_active_power)

hist(global_active_power, col="red", main="Global Active Power", ylab="Frequency", xlab="Global Active Power (kilowatts)")

#Save plot to a file

dev.copy(png, file="plot1.png", height=480, width=480)

#close graph device

dev.off()