Project 1- About data processing

The data for the project was used from US EPA website. Below is the link to the website.

https://aqs.epa.gov/aqsweb/airdata/download_files.html

The data is seperated for each year and has the following colums

Year
Days with AQI
Good Days
Moderate Days
Unhealthy for Sensitive Groups Days
Unhealthy Days
Very Unhealthy Days
Hazardous Days
Max AQI
90th Percentile AQI
Median AQI
Days CO
Days NO2
Days Ozone
Days SO2
Days PM2.5
Days PM10


For plotting purposes, the data of all the year files from 1980 to 2018 are complied into a single dataframe. And for each plots the required data is subsetted and other process such as removing the N/As or 0, Converting the values to percentage (if necessary) are done and plotting is done.

Another data file having the location of the counties was taken from the same link under "Site Listings". The latitude and longitude of each counties were taken from this data file to show the location of the Selected counties in leaflet map.