| addLabels {PBSmapping} | R Documentation |
Adds 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 |
EventData or PolyData to add (required). |
xlim |
range of X-coordinates. |
ylim |
range of Y-coordinates. |
polyProps |
PolyData specifying which labels to plot and their
properties. par parameters passed as direct arguments
supersede these data. |
placement |
one of "DATA", "CENTROID",
"MEAN_RANGE", or "MEAN_XY". |
polys |
PolySet to use for calculating label placement. |
rollup |
level of detail at which to process polys, and it
should match that in data. 1 = PIDs only,
2 = outer contours only, and 3 = no roll-up. |
cex |
vector describing character expansion factors (cycled by
EID or PID). |
col |
vector describing colours (cycled by EID or
PID). |
font |
vector describing fonts (cycled by EID or
PID). |
... |
additional par parameters for the
text function. |
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.
EventData or PolyData with X and Y columns
that can subsequently reproduce the labels on the plot. Modify this
data frame to tweak label positions.
addPoints,
calcCentroid,
calcMidRange,
calcSummary,
EventData,
plotPoints,
PolyData.
#--- 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)
#--- plot the map
plotMap (nepacLL, xlim=c(-129, -122.6), ylim=c(48, 51.1))
#--- add the labels
addLabels (labelData, placement="CENTROID", polys=nepacLL, col=2)