average_trends: Compare average trend over all sites with average trend over...

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

Description

Produces plots of annual average trends in the pollutant of interest aggregated over all sites, and over the long term sites only (i.e. sites open constantly over the period of interest).

Usage

average_trends(obs, pollutant, stat = "median",
  start.date = "2000-01-01", end.date = "2017-12-31",
  avg.time = "year")

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 used to average the ambient concentration data by year. Options: "median", "mean".
start.date	The starting date of the period of interest. Data capture to filter long term sites will be conducted using this date as the starting date.
end.date	The end date of the period of interest. Data capture to filter long term sites will be conducted using this date as the ending date.
avg.time	Resolution to average data to. Options: "year", "month", "day".

Value

A list of plots:

• average.trend - The average trend over all sites measuring during the period of interest.

• longterm.trend - The average trend over all long term sites measuring constantly throughout the period.

• trends.comparison - Comparison of the average.trend and the longterm.trend.

• average.allsites - The average trend for each individual sites measuring during the period of interest.

• longterm.allsites - The average trend for each individual long term site measuring constantly throughout the period.

Note: if there are no long term sites available for the period of interest, only the average.trend and average.allsites will be returned.

Examples

## Not run: 
average_trends(london_nox_data, pollutant = "nox", start.date = "2000-01-01", end.date = "2017-12-31")

## End(Not run)

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