R2G2 (version 1.0-2)

Pies2GE: Producing 3D pie-charts in Google Earth

Description

This function produces Google Earth 3D pie charts from geographical locations and frequency counts. The pie charts are displayed as regular n-sided polygons.

Usage

Pies2GE(center, obs, nesting = 0, goo = "Pies2GE.kml", colors = "auto", nedges = 20, orient = 0, maxAlt = 10000, radius = 50000)

Arguments

center

An array of geographical position for pies (lines = pies, columns = longitude and latitude in decimal degrees).

obs

Array of numerical and non-negative quantities that will be displayed in each the pie slices. This is is typically a pivot table with lines = pies and columns = quantities to plot within pies.

nesting

Vector for grouping the pies / pie slices into handy folders / subfolders (optional). The groups must be designated as numbers. The default nesting (nesting = 0) groups pie slices according to their color.

goo

Name of the KML file to that will be saved into the working directory (use getwd() to find it).

colors

Vector of colors corresponding to each species (one color per species), must be defined as hexadecimal values (as produced by usual R color palettes); leave to "auto" to get rainbow colors.

nedges

The number of edges, defining the general shape of the pie (3 -> triangle, 4 -> square, etc).

orient

the rotation factor of the pie-chart (in degrees).

maxAlt

the height (ceiling altitude) of the pies.

radius

The pie radius (in meters).

Value

A KML file is produced in the current working directory.

Details

The shape parameters (nedges, orient, radius and maxAlt) can be either a single value, that will be applied to all pies, or detailled values for each pie.

See Also

curvy GetEdges FancyPies table aggregate

Examples

## Preparing fake matrix
center = cbind(1:6, 1:6)
obs = cbind(1:6, 6:1, 1:6) #actual observations to be plot as a pie chart
nesting = rep(1:3, each = 2)
 
## data to be pie-charted
fakedata = cbind(nesting, center, obs)
colnames(fakedata) = c("Group","Lon","Lat","Slice1","Slice2","Slice3")
fakedata

## Producing KML - group pie slices according to color
Pies2GE(center = fakedata[, 2:3], 
	obs = fakedata[, 4:ncol(fakedata)], 
	nesting = fakedata[, 1], 
	goo = "Pies2GE_V1.kml", 
	nedges = 20, 
	orient = 0, 
	maxAlt = 1e4, 
	radius = 5e4)

## Producing KML - as before but also tweeking the shape / radius / height and color of each pie
Pies2GE(center = fakedata[, 2:3], 
	obs = fakedata[, 4:ncol(fakedata)], 
	nesting = 0, 
	goo = "Pies2GE_V2.kml", 
	nedges = c(3, 3, 4, 4, 20, 20), 
	orient = 0, 
	colors = topo.colors(ncol(obs)),
	maxAlt = c(3e4, 3e4, 5e4, 5e4, 1e5, 1e5), 
	radius = c(3e4, 3e4, 4e4, 4e4, 5e4, 5e4))

## Producing KML - group pies according to external information (experimental)
Pies2GE(center = fakedata[, 2:3], 
	obs = fakedata[, 4:ncol(fakedata)], 
	nesting = fakedata[, 1], 
	goo = "Pies2GE_V1.kml", 
	nedges = 20, 
	orient = 0, 
	maxAlt = 1e4, 
	radius = 5e4)