plotPoints function

Plot EventData/PolyData as Points

Plot EventData /PolyData , where each unique EID or (PID, SID) describes a point.

plotPoints (data, xlim = NULL, ylim = NULL, projection = FALSE,
            plt = c(0.11, 0.98, 0.12, 0.88), polyProps = NULL,
            cex = NULL, col = NULL, pch = NULL, axes = TRUE,
            tckLab = TRUE, tck = 0.014, tckMinor = 0.5 * tck, ...)

Arguments

• data: EventData or PolyData to plot (required).

• xlim: range of X-coordinates.

• ylim: range of Y-coordinates.

• projection: desired projection when PolySet lacks a projection attribute; one of "LL", "UTM", or a numeric value. If Boolean, specifies whether to check polys for a projection attribute.

• plt: four element numeric vector (x1, x2, y1, y2) giving the coordinates of the plot region measured as a fraction of the figure region. Set to NULL if mai in par is desired.

• polyProps: PolyData specifying which points to plot and their properties. par parameters passed as direct arguments supersede these data.

• cex: vector describing character expansion factors (cycled by EID or PID).

• col: vector describing colours (cycled by EID or PID).

• pch: vector describing plotting characters (cycled by EID

  or PID).

• axes: Boolean value; if TRUE, plot axes.

• tckLab: Boolean vector (length 1 or 2); if TRUE, label the major tick marks. If given a two-element vector, the first element describes the tick marks on the x-axis and the second element describes those on the y-axis.

• tck: numeric vector (length 1 or 2) describing the length of tick marks as a fraction of the smallest dimension. If tckLab = TRUE, these tick marks will be automatically labelled. If given a two-element vector, the first element describes the tick marks on the x-axis and the second element describes those on the y-axis.

• tckMinor: numeric vector (length 1 or 2) describing the length of tick marks as a fraction of the smallest dimension. These tick marks can not be automatically labelled. If given a two-element vector, the first element describes the tick marks on the x-axis and the second element describes those on the y-axis.

• ...: additional par parameters, or the arguments main, sub, xlab, or ylab for the title function.

Details

This function clips data to xlim and ylim before plotting. It only adds PolyData containing X and Y columns.

The function creates a blank plot when polys equals NULL. In this case, the user must supply both xlim and ylim arguments. Alternatively, it accepts the argument type = "n" as part of ..., which is equivalent to specifying polys = NULL, but requires a PolySet . In both cases, the function's behaviour changes slightly. To resemble the plot function, it plots the border, labels, and other parts according to par parameters such as col.

For additional help on the arguments cex, col, and pch, please see par.

Returns

PolyData consisting of the PolyProps used to create the plot.

Note

To satisfy the aspect ratio, this plotting routine resizes the plot region. Consequently, par parameters such as plt, mai, and mar will change. When the function terminates, these changes persist to allow for additions to the plot.

Author(s)

Nicholas M. Boers, Staff Software Engineer

Jobber, Edmonton AB

Last modified Rd: 2013-04-10

See Also

addPoints, combineEvents, convDP, findPolys, locateEvents.

Examples

local(envir=.PBSmapEnv,expr={
  oldpar = par(no.readonly=TRUE)
  #--- load the data (if using R)
  if (!is.null(version$language) && (version$language=="R"))
    data(nepacLL,surveyData,envir=.PBSmapEnv)
  #--- plot a map
  plotMap(nepacLL, xlim=c(-136, -125), ylim=c(48, 57))
  #--- add events
  addPoints(surveyData, col=1:7)
  par(oldpar)
})