plot1.r.R

# Exploratory Data Analysis -  
# Q.1. Have total emissions from PM2.5 decreased in the United States from 1999 to 2008? Using the base plotting system, make a plot showing the total PM2.5 emission from all sources for each of the years 1999, 2002, 2005, and 2008.

# upload data files
NEI <- readRDS("~/summarySCC_PM25.rds")
View(NEI)

SCC <- readRDS("~/Source_Classification_Code.rds")
View(SCC)

NEI_sampling <- NEI[sample(nrow(NEI), size=2000, replace=F), ]

Emissions <- aggregate(NEI[, 'Emissions'], by=list(NEI$year), FUN=sum)
Emissions$PM <- round(Emissions[,2]/1000,2)

png(filename='~/Course Project 2/plot1.png')

barplot(Emissions$PM, names.arg=Emissions$Group.1, 
        main=expression('Total Emission of PM'[2.5]),
        xlab='Year', ylab=expression(paste('PM', ''[2.5], ' in Kilotons')))

dev.off()