Usage
draw.recmap(data, file='screen', subset=NULL, group=NULL, bbox=NULL,
projection='longlat', zoom=2, margin=1, points=0, pcol='red', lines=0,
lcol='red', gcircle=FALSE, density=FALSE, grid.size=300, mask='sea',
all.data=FALSE, height=1000, width=0, units='px', col='lemonchiffon',
bg='lightblue1', border=NA, lwd=1, legend='none', title = NULL, labels=NULL,
lcex=0, alpha=0.2, ...)
Arguments
data
a dataframe with, minimally, columns labelled 'lat' and 'lon' giving the co-ordinates
of locations (in decimal degrees). Note there should be one row per encounter
(i.e. a recovery will appear as 2+ rows).
file
a valid filename to which the map should be plotted. Currently supports png, jpg
(or jpeg), or tif (tiff) extensions.
subset
a character string indicating subset of rows to use, any logical expression involving
column names (or numbers) should work.
group
a character string, the variable name (within data) indicating the grouping variable
to be displayed in the legend.
bbox
a numeric vector giving the map boundary in decimal degrees as c(long_min, long_max,
lat_min, lat_max). If some data are outwith this box a warning is issued.
projection
a character string indicating the projection to be used, currently only 'longlat' or
'mercator' work.
zoom
a number indicating resolution of map to plot: 1 - low resolution suitable for
global maps; 2 - fine for most purposes (the default); and 3 - for large maps or
small areas where a higher resolution is needed.
margin
a number (in decimal degrees) to pad the map by around the extreme points.
points
an integer, if >0 then points will be plotted at that size, relative to par('cex').
pcol
colour to plot the points.
lines
an integer, if >0 then lines will be plotted at that width.
lcol
colour to plot the lines.
gcircle
logical, should the lines be plotted as great circle routes.
density
logical, if TRUE overlay kernel density smooth (heat map) generated from data,
see details.
grid.size
numeric, indicating the number of points over which to calculate the density grid,
increase from the default 300 for a smoother pattern, decrease for quicker computation.
mask
if density=TRUE, mask could be either 'land' or 'sea' (the default); this is purely
presentational, it doesn't alter the kernel calculation.
all.data
logical, if bbox is given, should all the data be used in creating the heat map,
or only those displayed.
height
the height of the map canvas (in pixels unless units is given).
Specify only one of height or width; height will be ignored of both given.
width
the width of the map canvas (in pixels unless units is given). Specify only one
of height or width.
units
the units in which height and width are given. Can be px (pixels, the default),
in (inches), cm or mm.
col
colour for land areas, the default colours are designed to also print well in
greyscale.
bg
colour for ocean areas.
border
colour to draw the country borders (and coastal outline), use NA to suppress these.
lwd
numeric, width of border lines.
legend
keyword indicating position from the list "none", "bottomright", "bottom",
"bottomleft", "left", "topleft", "top", "topright", "right" and "center". Use
inset=c(x,y) for finer control of placement, where x, y between 0 and 1.
lcex
if a legend is included, size of the legend labels relative to par('cex').
alpha
if a legend is included, transparency of the legend rectangle, as a proportional
opacity from 0 (fully transparent) to 1 (opaque).
title
if a legend is included, the title to be added in the legend box.
labels
vector of character labels to be used in identifying the group levels. If this
does not match the number of group levels, then it will be ignored.
...
other arguments to pass to legend().