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percentileMap() creates a leaflet map using percentile roses as markers. Any number of pollutants can be specified using the pollutant argument, and multiple layers of markers can be added and toggled between using control.


  pollutant = NULL,
  percentile = c(25, 50, 75, 90, 95),
  intervals = "fixed",
  latitude = NULL,
  longitude = NULL,
  control = NULL,
  popup = NULL,
  label = NULL,
  provider = "OpenStreetMap",
  cols = "turbo",
  alpha = 1,
  key = FALSE,
  draw.legend = TRUE,
  collapse.control = FALSE,
  d.icon = 200,
  d.fig = 3.5,
  type = deprecated(),



A data frame. The data frame must contain the data to plot the directional analysis marker, which includes wind speed (ws), wind direction (wd), and the column representing the concentration of a pollutant. In addition, data must include a decimal latitude and longitude.


The column name(s) of the pollutant(s) to plot. If multiple pollutants are specified, they can be toggled between using a "layer control" interface.


The percentile value(s) to plot. Must be between 0–100. If percentile = NA then only a mean line will be shown.


One of:

  • "fixed" (the default) which ensures all of the markers use the same radial axis scale.

  • "free" which allows all of the markers to use different radial axis scales.

  • A numeric vector defining a sequence of numbers to use as the intervals, e.g., intervals = c(0, 10, 30, 50).

latitude, longitude

The decimal latitude/longitude. If not provided, will be automatically inferred from data by looking for a column named "lat"/"latitude" or "lon"/"lng"/"long"/"longitude" (case-insensitively).


Used for splitting the input data into different groups which can be selected between using a "layer control" interface, passed to the type argument of openair::cutData(). control cannot be used if multiple pollutant columns have been provided.


Columns to be used as the HTML content for marker popups. Popups may be useful to show information about the individual sites (e.g., site names, codes, types, etc.). If a vector of column names are provided they are passed to buildPopup() using its default values.


Column to be used as the HTML content for hover-over labels. Labels are useful for the same reasons as popups, though are typically shorter.


The base map(s) to be used. See for a list of all base maps that can be used. If multiple base maps are provided, they can be toggled between using a "layer control" interface. By default, the interface will use the provider names as labels, but users can define their own using a named vector (e.g., c("Default" = "OpenStreetMap", "Satellite" = "Esri.WorldImagery"))


The colours used for plotting. See openair::openColours() for more information.


The alpha transparency to use for the plotting surface (a value between 0 and 1 with zero being fully transparent and 1 fully opaque).


Should a key for each marker be drawn? Default is FALSE.


Should a shared legend be created at the side of the map? Default is TRUE.


Should the "layer control" interface be collapsed? Defaults to FALSE.


The diameter of the plot on the map in pixels. This will affect the size of the individual polar markers. Alternatively, a vector in the form c(width, height) can be provided if a non-circular marker is desired.


The diameter of the plots to be produced using openair in inches. This will affect the resolution of the markers on the map. Alternatively, a vector in the form c(width, height) can be provided if a non-circular marker is desired.


[Deprecated]. Different sites are now automatically detected based on latitude and longitude. Please use label and/or popup to label different sites.


Arguments passed on to openair::percentileRose


Name of wind direction field.


Should the wind direction data be smoothed using a cyclic spline?


When method = "default" the supplied percentiles by wind direction are calculated. When method = "cpf" the conditional probability function (CPF) is plotted and a single (usually high) percentile level is supplied. The CPF is defined as CPF = my/ny, where my is the number of samples in the wind sector y with mixing ratios greater than the overall percentile concentration, and ny is the total number of samples in the same wind sector (see Ashbaugh et al., 1985).


Default angle of “spokes” is when smooth = FALSE.


Show the mean by wind direction as a line?


Line type for mean line.


Line width for mean line.


Line colour for mean line.


Should the percentile intervals be filled (default) or should lines be drawn (fill = FALSE).


Sometimes the placement of the scale may interfere with an interesting feature. The user can therefore set angle.scale to any value between 0 and 360 degrees to mitigate such problems. For example angle.scale = 45 will draw the scale heading in a NE direction.


Either TRUE (default) or FALSE. If TRUE titles and axis labels will automatically try and format pollutant names and units properly e.g. by subscripting the `2' in NO2.


Adds additional text/labels to the scale key. For example, passing the options key.header = "header", key.footer = "footer1" adds addition text above and below the scale key. These arguments are passed to drawOpenKey via quickText, applying the auto.text argument, to handle formatting.


see key.footer.


Location where the scale key is to plotted. Allowed arguments currently include "top", "right", "bottom" and "left".


A leaflet object.

See also

the original openair::percentileRose()

percentileMapStatic() for the static ggmap equivalent of percentileMap()

Other interactive directional analysis maps: annulusMap(), diffMap(), freqMap(), polarMap(), pollroseMap(), windroseMap()


if (FALSE) {
  pollutant = "nox",
  provider = "Stamen.Toner"