Course1_ysy

[Lilian221111]

#download
setwd("C:/Users/yan_s/Desktop")
if(!file.exists("data"))dir.create("data")
fileUrl <- 'https://d396qusza40orc.cloudfront.net/exdata%2Fdata%2Fhousehold_power_consumption.zip'
download.file(fileUrl, destfile = './data/household_power_consumption.zip')
unzip('./data/household_power_consumption.zip', exdir = './data')

#read data
files <- file("./data/household_power_consumption.txt")
data <- read.table(text = grep("^[1,2]/2/2007",readLines(files),value=TRUE), sep = ';', col.names = c("Date", "Time", "Global_active_power", "Global_reactive_power", "Voltage", "Global_intensity", "Sub_metering_1", "Sub_metering_2", "Sub_metering_3"), na.strings = '?')

#screen quickly
head(data)
dim(data)

#plot1
if(!file.exists('figures')) dir.create('figures')
png(filename = './figures/plot1.png', width = 480, height = 480, units='px')
hist(data$Global_active_power,breaks = 12,col="red",xlab="Global Active Power(kilowatts)",ylab = "Frequency",main = "Global Active Power")
dev.off()

#plot2
data$Date <- as.Date(data$Date, format = '%d/%m/%Y')
data$DateTime <- as.POSIXct(paste(data$Date, data$Time))
png(filename = './figures/plot2.png', width = 480, height = 480, units='px')
Sys.setlocale(category = "LC_ALL", locale = "english")
plot(data$DateTime, data$Global_active_power, xlab = '', ylab = 'Global Active Power (kilowatt)',type = "l")
dev.off()

#plot3
data$Date <- as.Date(data$Date, format = '%d/%m/%Y')
data$DateTime <- as.POSIXct(paste(data$Date, data$Time))
png(filename = './figures/plot3.png', width = 480, height = 480, units='px')
Sys.setlocale(category = "LC_ALL", locale = "english")
plot(data$DateTime, data$Sub_metering_1, xlab = '', ylab = 'Energy sub metering', type = 'l')
lines(data$DateTime, data$Sub_metering_2, col = 'red')
lines(data$DateTime, data$Sub_metering_3, col = 'blue')
legend('topright', col = c('black', 'red', 'blue'), legend = c('Sub_metering_1', 'Sub_metering_2', 'Sub_metering_3'), lwd = 1)
dev.off()

#plot4
data$Date <- as.Date(data$Date, format = '%d/%m/%Y')
data$DateTime <- as.POSIXct(paste(data$Date, data$Time))
png(filename = './figures/plot4.png', width = 480, height = 480, units='px')
Sys.setlocale(category = "LC_ALL", locale = "english")
par(mfrow = c(2, 2))
with(data, {
plot(DateTime, Global_active_power, xlab="",ylab = "Global Active Power",type="l")
plot(DateTime, Voltage, xlab="datetime",ylab = "Voltage",type="l")
plot(data$DateTime, data$Sub_metering_1, xlab = '', ylab = 'Energy sub metering', type = 'l')
lines(data$DateTime, data$Sub_metering_2, col = 'red')
lines(data$DateTime, data$Sub_metering_3, col = 'blue')
plot(data$DateTime, Global_reactive_power, xlab = 'datetime', ylab = 'Global_reactive_power', type = 'l')
})
dev.off()