site_flux_bias: The difference in concentration between opening and closing...

In pollylang/aqtrends: Tools for trend analysis of air quality network data

Description

Detects a difference in average concentration of the pollutant of interest between sites opening and closing in a given year (i.e. a bias towards more/less polluted locations) and any change in this bias over time.

Usage

site_flux_bias(obs, pollutant, stat = "median")

Arguments

obs	A data frame of ambient pollutant concentration data. Must contain the columns: site_code, date, value. If 'pollutant' is a pollutant ratio, the data frames of the corresponding pollutants must be supplied as a list of data frames in the order they are given in the ratio. E.g. for pollutant = "no2/nox", obs = list(obs.no2, obs.nox).
pollutant	The pollutant of interest (character string). To calculate rolling change trend for a pollutant ratio, separate the two pollutants with a forward slash e.g. pollutant = "no2/nox".
stat	The metric (character string) used to average the ambient concentration data by year. Options: "median", "mean".

Value

A list of plots:

• difference - a plot of the difference between the average concentration of opening sites and closing sites as a function of year.

• cumulative_difference - the cumulative sum of differences in average concentration of opening sites and closing sites as a function of year.

• weighted_cumulative_difference - the cumulative sum of differences in average concentration of opening and closing sites weighted by the number of opening/closing sites as a function of year.

• compare - a side-by-side comparison of the difference, cumulative_difference and weighted_cumulative_difference plots.

Examples

## Not run: 
site_flux_bias(london_nox_data, pollutant = "nox", stat = "median")

## End(Not run)

pollylang/aqtrends documentation built on May 20, 2019, 8:24 p.m.