Add Labels to an Existing Plot
Add the label column of data to the existing plot.
addLabels (data, xlim = NULL, ylim = NULL, polyProps = NULL,
placement = "DATA", polys = NULL, rollup = 3,
cex = NULL, col = NULL, font = NULL, ...)data |
|
xlim |
range of X-coordinates. |
ylim |
range of Y-coordinates. |
polyProps |
PolyData specifying which labels to plot and their
properties. |
placement |
one of |
polys |
PolySet to use for calculating label placement. |
rollup |
level of detail at which to process |
cex |
vector describing character expansion factors (cycled by
|
col |
vector describing colours (cycled by |
font |
vector describing fonts (cycled by |
... |
If data is EventData, it must minimally contain the columns
EID, X, Y, and label. Since the
EID column does not match a column in polys, set
placement = "DATA". The function plots each label at
its corresponding X/Y coordinate.
If data is PolyData, it must minimally contain the columns
PID and label. If it also contains X and
Y columns, set placement = "DATA" to plot labels at
those coordinates. Otherwise, set placement to one of
"CENTROID", "MEAN_RANGE", or "MEAN_XY". When
placement != "DATA", supply a PolySet polys. Using this
PolySet, the function calculates a centroid, mean range, or mean X/Y
coordinate for each polygon, and then links those PolyData with
data by PID/SID to determine label
coordinates.
If data contains both PID and EID columns, the
function assumes it is PolyData and ignores the EID
column.
For additional help on the arguments cex, col, and
font, please see par.
Nicholas M. Boers, Associate Professor – Computer Science
MacEwan University, Edmonton AB
Last modified Rd: 2013-04-10
local(envir=.PBSmapEnv,expr={
oldpar = par(no.readonly=TRUE)
#--- create sample PolyData to label Vancouver Island
labelData <- data.frame(PID=33, label="Vancouver Island");
#--- load data
if (!is.null(version$language) && (version$language == "R"))
data(nepacLL,envir=.PBSmapEnv)
#--- plot the map
plotMap(nepacLL,xlim=c(-129,-122.6),ylim=c(48,51.1),col="lemonchiffon")
#--- add the labels
addLabels(labelData,placement="CENTROID",polys=nepacLL,cex=1.2,col=2,font=2)
par(oldpar)
})Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.