openair (version 0.9-2)

GoogleMapsPlot: GoogleMapsPlot

Description

[IN DEVELOPMENT] Map plotting for openair data sets.

Usage

GoogleMapsPlot(mydata, latitude = "latitude", longitude = "longitude",
  type = "default", xlim, ylim, pollutant = NULL, labels = NULL,
  cols = "default", limits = c(0, 100), cex = pollutant, pch = NULL,
  cex.range = c(2, 10), xlab = longitude, ylab = latitude, main = "",
  axes = TRUE, map = NULL, map.raster = TRUE, map.cols = NULL,
  aspect = NULL, as.table = TRUE, plot.type = "xy",
  plot.transparent = FALSE, key = NULL, key.position = "right",
  key.header = "", key.footer = pollutant, auto.text = TRUE, ...)

Arguments

mydata

The openair data frame to use to generate the GoogleMapsPlot plot.

latitude,longitude

The names of the data series in mydata giving the latitudes and longitudes, respectively, of measurements. If only one latitude longitude pair are supplied, the function applies a default range to the plot. To override this either se

type

The type of data conditioning to apply before plotting. The default is will produce a single plot using the entire data. Other type options include hour (for hour of the day), weekday (for day of the week) and

xlim,ylim

The x-axis and y-axis size ranges. By default these sized on the basis of latitude and longitude, but can be forced as part of the plot call. (NOTE: This are in-development and should be used with care. The RgoogleMaps ar

pollutant

If supplied, the name of a pollutant or variable in mydata that is to be evaluated at the each measurement point. Depending on settings, nominally cols and cex, the evaluation can be by colour, size or both.

labels

If supplied, either the name of mydata column/field containing the labels to be used or a list, containing that field name (as labels), and any other label properties, e.g. cex, col, etc, require

cols

The colour set to use to colour scaled data. Typically, cols is passed to openColours for evaluation, but can be forced to one colour using e.g. col = "red". The special case cols = "greyscale" f

limits

By default, the data colour scale is fitted to the total data range. However, there are circumstances when the user may wish to set different ones. In such cases limits can be set in the form c(lower, upper) to modify the

cex

The size of data points plotted on maps. By default this NULL or pollutant if supplied. If NULL all points are plotted an equal size. If pollutant or the name of another variable in mydata<

pch

The plot symbol to be used when plotting data. By default this is a solid circle (pch = 20), but can be any predefined symbol, e.g. pch = 1 is the open circle symbol used in most standard R plots. pch may als

cex.range

The range to rescale cex values to if cex is supplied as a mydata variable name. This is intended to provide sensible data point points regardless of the variable value range but may be require fine-tuning.

xlab,ylab,main

The x-axis, y-axis and main title labels to be added to the plot. All labels are passed via quickText to handle formatting if enabled (auto.text = TRUE). By default GoogleMapsPlot uses latitude a

axes

An alternative (short hand) option to add/remove (TRUE/FALSE) all x and y axis annotation and labelling.

map

If supplied, an RgoogleMaps output, to be used as a background map. If NULL (as in default), a map is produced using the RgoogleMaps-package function MapBackground, the supplied latitude

map.raster

Should the map be plotted as a raster object? The default TRUE uses panel.GoogleMapsRaster to produce the map layer, while the alternative (FALSE) uses panel.GoogleMaps. (NOTE: The raster version

map.cols

Like cols a colour scale, but, if supplied, used to recolour the map layer before plotting. (NOTE: If set, this will override cols = "greyscale".)

aspect

The aspect ratio of the plot. If NULL (default), this is calculated by the function based on the data and xlim and ylim ranges.

as.table

as.table is a lattice option that controls the order in which multiple panels are displayed. The default (TRUE) produces layouts similar to other openair plot.

plot.type

The method to use to produce the data layer for the plot. By default (plot.type = "xy"), this is an x-y style scatter plot, but can also be other pre-defined options (e.g. "level" for a levelplot) or a user-defined panel of a similar

plot.transparent

Data layer transparency control. When enabled, this forces colours used in the data layer to transparent, and can be a numeric setting the colour density, from invisible (0) to solid (1), or a logical (TRUE applying default 0.5). Note

key

Fine control for the color scale key. By default (key = NULL) the key is generated is a colour range exists, but can be forced (key = TRUE/FALSE) or controlled at a higher level (via drawOpenKey).

key.position

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

key.header,key.footer

Header and footer labels to add to colour key, if drawn. If enabled (auto.text = TRUE), these arguments are passed to the scale key (drawOpenKey) via quickText to handle formatting.

auto.text

Automatic routine text formatting. auto.text = TRUE allows labels (xlab, ylab, main, etc.) to be passed to the plot via quickText. auto.text = FALSE turns this option o

...

Addition options are passed on to cutData for type handling, MapBackground in RgoogleMaps for map layer production, and xyplot in lattice for data layer production.

Value

• As well as generating the plot itself, GoogleMapsPlot also returns an object of class ``openair''. The object includes three main components: call, the command used to generate the plot; data, the data frame of summarised information used to make the plot; and plot, the plot itself. If retained, e.g. using output <- GoogleMapsPlot(mydata), this output can be used to recover the data, reproduce or rework the original plot or undertake further analysis.

  An openair output can be manipulated using a number of generic operations, including print, plot and summary. See openair.generics for further details.

Details

GoogleMapsPlot is an IN DEVELOPMENT function.

It combines a dedicated map layer, e.g. panel.GoogleMaps, or (the default) panel.GoogleMapsRaster, and standard lattice panels such as panel.xyplot or panel.levelplot as a data layer, to produce map-based data visualisations.

It provides lattice-style conditioning/handling for RgoogleMaps outputs.

References

This function makes extensive use of code developed by others.

RgoogleMaps: Markus Loecher and Sense Networks (2011). RgoogleMaps: Overlays on Google map tiles in R. R package version 1.1.9.6. http://CRAN.R-project.org/package=RgoogleMaps

lattice: Sarkar, Deepayan (2008) Lattice: Multivariate Data Visualization with R. Springer, New York. ISBN 978-0-387-75968-5

See Also

RgoogleMaps, xyplot, panel.xyplot and panel.levelplot

Examples

#TO BE CONFIRMED