library(dplyr)

output_file = "plot4.png"

input_file = "household_power_consumption.txt"

from <- "2007-02-01"

to <- "2007-02-02"

label_y <- 'Energy Submetering'

label_x <- ''

colors <- c("black", "red", "blue")

readPowerData <- function(fileName) {

df <- read.delim(file = fileName,header = TRUE,dec = '.',na.strings = "?",

colClasses =

c("character", #date

"character", #time

"numeric", #Global_active_power

"numeric", #Global_reactive_power

"numeric", #Voltage

"numeric", #Global_intensity

"numeric", #Sub_metering_1

"numeric", #Sub_metering_2

"numeric"),

sep = ";")

df <- tbl_df(df)

df <- mutate(df, DateTime=paste(Date,Time))

df <- select(df, -Date, -Time)

df$DateTime <- as.POSIXct(strptime(df$DateTime, format="%d/%m/%Y %H:%M:%S", tz=""))

df <- mutate(df, DateText=format(DateTime, "%Y-%m-%d"))

df

}

drawPlot <- function() {

all_household_data <- readPowerData(input_file)

columns <- select(all_household_data,

-Global_intensity)

rm(all_household_data)

one <- grepl(columns$DateText,pattern = from, fixed = TRUE)

two <- grepl(columns$DateText,pattern = to, fixed = TRUE)

combined <- one | two

days_of_interest <- columns[three,]

par(mfrow = c(2, 2))

with(days_of_interest,

plot(DateTime, Global_active_power, type="l", ylab="Global Active Power", xlab=""))

with(days_of_interest,

plot(DateTime, Voltage, type="l", ylab="Voltage", xlab="datetime"))

with(days_of_interest,

plot(DateTime, Sub_metering_1, type="l", ylab="Energy Submetering", xlab="", col=colors[1] ))

with(days_of_interest, lines(DateTime, Sub_metering_2, type="l", col=colors[2]))

with(days_of_interest, lines(DateTime, Sub_metering_3, type="l", col=colors[3]))

legend("topright",

c("Sub_metering_1",

"Sub_metering_2",

"Sub_metering_3"),

lty=1, lwd=2, col=colors)

with(days_of_interest,

plot(DateTime, Global_reactive_power, type="l", ylab="Global_reactive_power", xlab="datetime"))

}

# Prepare output device

png(filename = output_file,

width = 480,

height = 480,

units = "px",

pointsize = 12,

bg="white")

# Draw

drawPlot()

# Flush output device

dev.off()