pointsg.circular: Add Points to a Circular Plot - geographics
In apjmason/circular: Circular Statistics

Description Usage Arguments Details Value Author(s) See Also Examples

Add points to a plot of circular data points on the current graphics device with geographic stacking/binning behavior.

## S3 method for class 'circular'
pointsg(x, pch = 16, cex = 1, stack = FALSE,
  start.sep=0, sep = 0.025, 
  shrink = 1, bins = NULL, col = NULL, next.points = NULL, 
  plot.info = NULL, zero = NULL, rotation = NULL, ...)

`x`	a vector, matrix or data.frame. The object is coerced to class `circular`.
`pch`	point character to use. See help on `par`.
`cex`	point character size. See help on par.
`stack`	logical: if `TRUE`, points are stacked on the perimeter of the circle. Otherwise, all points are plotted on the perimeter of the circle. Default is `FALSE`.
`start.sep`	constant used to specify the distance between the center of the point and the axis.
`sep`	constant used to specify the distance between stacked points, if `stack==TRUE` or in the case of more than one dataset. Default is 0.025; smaller values will create smaller spaces.
`shrink`	parameter that controls the size of the plotted circle. Default is 1. Larger values shrink the circle, while smaller values enlarge the circle.
`bins`	if `stack==TRUE`, bins is the number of arcs to partition the circle with.
`col`	color of the points. The values are recycled if needed.
`next.points`	if `stack=FALSE`, the distance from the circle the next dataset is plotted. Ingored if `plot.info` is provided.
`plot.info`	an object from `plot.circular` that contains information on the `zero`, the `rotation` and `next.points`.
`zero`	the zero of the plot. Ignored if `plot.info` is provided.
`rotation`	the rotation of the plot. Ignored if `plot.info` is provided.
`...`	futher parameters passed to `points.default`.

When there are many closely distributed observations, stacking is recommended. When stacking the points, if there are many points in a particular bin, it may be necessary to shrink the plot of the circle so that all points fit. This is controlled with the parameter shrink. Generally the parameter sep does not need adjustment, however, when shrinking the plot, or for a very large number of observations, it may be helpful. Since version 0.3-9 the intervals are on the form [a,b).

A list with information on the plot: zero, rotation and next.points.

Claudio Agostinelli

plot.circular and lines.circular.

# Generate sample data of 1 observation every 10 degrees
# as circular data, 'geographics' sets 0 up with clockwise rotation 
data.1 <- circular(seq(0,350,10),units="degrees",template="geographics") 

# second data set at 5 degree intervals
data.2 <- circular(seq(0,355,5),units="degrees",template="geographics") 
res <- plot.circular(data.1, col=1) 

# stacking data with pointsg shifts bin midpoints to cardinal compass points
pointsg.circular(data.2, plot.info=res, stack=TRUE, bins=16, col=2)

# without stack=TRUE, behaves identical to points.circular
pointsg.circular(data.2, plot.info=res, col=2)