The percentileMap() function creates a map using polar percentile roses as
markers. Any number of pollutants can be specified using the pollutant
argument, and multiple layers of markers can be created using type. By
default, these maps are dynamic and can be panned, zoomed, and otherwise
interacted with. Using the static argument allows for static images to be
produced instead.
percentileMap(
data,
pollutant = NULL,
percentile = c(25, 50, 75, 90, 95),
intervals = "fixed",
latitude = NULL,
longitude = NULL,
crs = 4326,
type = NULL,
popup = NULL,
label = NULL,
provider = "OpenStreetMap",
cols = "turbo",
alpha = 1,
key = FALSE,
legend = TRUE,
legend.position = NULL,
legend.title = NULL,
legend.title.autotext = TRUE,
control.collapsed = FALSE,
control.position = "topright",
control.autotext = TRUE,
d.icon = 200,
d.fig = 3.5,
static = FALSE,
static.nrow = NULL,
...,
control = NULL
)Either:
Dynamic: A leaflet object
Static: A ggplot2 object using ggplot2::coord_sf() coordinates with a ggspatial basemap
Input data table with pollutant, wind, and geo-spatial information.
required | scope: dynamic & static
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 (or X/Y coordinate
used in conjunction with crs).
Pollutant name(s).
required | scope: dynamic & static
The column name(s) of the pollutant(s) to plot. If multiple pollutants are
specified the type argument will no longer be able to be used, and:
Dynamic: The pollutants can be toggled between using a "layer control" menu.
Static:: The pollutants will each appear in a different panel.
Multiple pollutants prohibit the use of the type argument.
The percentile values for the colour scale bin.
default: c(25, 50, 75, 90, 95) | scope: dynamic & static
The percentile value(s) to plot using openair::percentileRose(). Must be
a vector of values between 0 and 100. If percentile = NA then only a
mean line will be shown.
Specifier for the percentile rose radial axis intervals.
default: "fixed" | scope: dynamic & static
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).
The decimal latitude(Y)/longitude(X).
default: NULL | scope: dynamic & static
Column names representing the decimal latitude and longitude (or other Y/X
coordinate if using a different crs). If not provided, will be
automatically inferred from data by looking for a column named
"lat"/"latitude" or "lon"/"lng"/"long"/"longitude" (case-insensitively).
The coordinate reference system (CRS).
default: 4326 | scope: dynamic & static
The coordinate reference system (CRS) of the data, passed to
sf::st_crs(). By default this is EPSG:4326, the
CRS associated with the commonly used latitude and longitude coordinates.
Different coordinate systems can be specified using crs (e.g., crs = 27700 for the British National Grid). Note that
non-lat/lng coordinate systems will be re-projected to EPSG:4326 for
plotting on the map.
A method to condition the data for separate plotting.
default: NULL | scope: dynamic & static
Used for splitting the input data into different groups, passed to the
type argument of openair::cutData(). When type is specified:
Dynamic: The different data splits can be toggled between using a "layer control" menu.
Static:: The data splits will each appear in a different panel.
type cannot be used if multiple pollutant columns have been provided.
Content for marker popups on dynamic maps.
default: NULL | scope: dynamic
Columns to be used as the HTML content for marker popups on dynamic maps.
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.
Content for marker hover-over on dynamic maps.
default: NULL | scope: dynamic
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 basemap(s) to be used.
default: "OpenStreetMap" | scope: dynamic & static
The base map(s) to be used beneath the polar markers. If not provided, will
default to "OpenStreetMap"/"osm" for both dynamic and static maps.
Dynamic: Any number of leaflet::providers.
See http://leaflet-extras.github.io/leaflet-providers/preview/ 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"))
Static: One of rosm::osm.types().
There is some overlap in static and dynamic providers. For example,
{ggspatial} uses "osm" to specify "OpenStreetMap". When static providers
are provided to dynamic maps or vice versa, {openairmaps} will attempt to
substitute the correct provider string.
Colours to use for plotting.
default: "turbo" | scope: dynamic & static
The colours used for plotting, passed to openair::openColours(). The
default, "turbo", is a rainbow palette with relatively perceptually
uniform colours. Read more about this palette at
https://research.google/blog/turbo-an-improved-rainbow-colormap-for-visualization/.
Transparency value for polar markers.
default: 1 | scope: dynamic & static
A value between 0 (fully transparent) and 1 (fully opaque).
Draw individual marker legends?
default: FALSE | scope: dynamic & static
Draw a key for each individual marker? Potentially useful when limits = "free", but of limited use otherwise.
Draw a shared legend?
default: TRUE | scope: dynamic & static
When all markers share the same colour scale (e.g., when limits != "free"
in polarMap()), should a shared legend be created at the side of the map?
Position of the shared legend.
default: NULL | scope: dynamic & static
When legend = TRUE, where should the legend be placed?
Dynamic: One of "topright", "topright", "bottomleft" or "bottomright". Passed to the position argument of leaflet::addLegend().
Static:: One of "top", "right", "bottom" or "left". Passed to the legend.position argument of ggplot2::theme().
Title of the legend.
default: NULL | scope: dynamic & static
By default, when legend.title = NULL, the function will attempt to
provide a sensible legend title. legend.title allows users to overwrite
this - for example, to include units or other contextual information. For
dynamic maps, users may wish to use HTML tags to format the title.
Automatically format the title of the legend?
default: TRUE | scope: dynamic & static
When legend.title.autotext = TRUE, legend.title will be first run
through quickTextHTML() (dynamic) or openair::quickText() (static).
Show the layer control as a collapsed?
default: FALSE | scope: dynamic
For dynamic maps, should the "layer control" interface be collapsed? If
TRUE, users will have to hover over an icon to view the options.
Position of the layer control menu
default: "topright" | scope: dynamic
When type != NULL, or multiple pollutants are specified, where should the
"layer control" interface be placed? One of "topleft", "topright",
"bottomleft" or "bottomright". Passed to the position argument of
leaflet::addLayersControl().
Automatically format the content of the layer control menu?
default: TRUE | scope: dynamic
When control.autotext = TRUE, the content of the "layer control"
interface will be first run through quickTextHTML().
The diameter of the plot on the map in pixels.
default: 200 | scope: dynamic & static
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.
default: 3.5 | scope: dynamic & static
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.
Produce a static map?
default: FALSE
This controls whether a dynamic or static map is produced. The former is the default and is broadly more useful, but the latter may be preferable for DOCX or PDF outputs (e.g., academic papers).
Number of rows in a static map.
default: NULL | scope: static
Controls the number of rows of panels on a static map when multiple
pollutants or type are specified; passed to the nrow argument of
ggplot2::facet_wrap(). The default, NULL, results in a roughly square
grid of panels.
Arguments passed on to openair::percentileRose
wdName of wind direction field.
smoothShould the wind direction data be smoothed using a cyclic spline?
methodWhen 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).
angleDefault angle of “spokes” is when smooth = FALSE.
meanShow the mean by wind direction as a line?
mean.ltyLine type for mean line.
mean.lwdLine width for mean line.
mean.colLine colour for mean line.
fillShould the percentile intervals be filled (default) or should
lines be drawn (fill = FALSE).
angle.scaleSometimes 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.
auto.textEither 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.
key.headerAdds 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.
key.footersee key.footer.
key.positionLocation where the scale key is to plotted. Allowed
arguments currently include "top", "right", "bottom"
and "left".
Deprecated. Please use type.
As the outputs of the static directional analysis functions are ggplot2
figures, further customisation is possible using functions such as
ggplot2::theme(), ggplot2::guides() and ggplot2::labs().
If multiple pollutants are specified, subscripting (e.g., the "x" in "NOx")
is achieved using the ggtext package. Therefore if you
choose to override the plot theme, it is recommended to use
[ggplot2::theme()] and [ggtext::element_markdown()] to define the
strip.text parameter.
When arguments like limits, percentile or breaks are defined, a
legend is automatically added to the figure. Legends can be removed using
ggplot2::theme(legend.position = "none"), or further customised using
ggplot2::guides() and either color = ggplot2::guide_colourbar() for
continuous legends or fill = ggplot2::guide_legend() for discrete
legends.
openair::percentileRose()
Other directional analysis maps:
annulusMap(),
diffMap(),
freqMap(),
polarMap(),
pollroseMap(),
windroseMap()
if (FALSE) {
percentileMap(polar_data,
pollutant = "nox",
provider = "CartoDB.Voyager"
)
}
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