spatstat.geom (version 3.8-2)

perspPoints: Draw Points or Lines on a Surface Viewed in Perspective

Description

After a surface has been plotted in a perspective view using persp.im, these functions can be used to draw points or lines on the surface.

Usage

perspPoints(x, y=NULL, ..., Z, M, occluded=TRUE)
perspLines(x, y = NULL, ..., Z, M, occluded=TRUE)
perspSegments(x0, y0 = NULL, x1 = NULL, y1 = NULL, ..., Z, M, occluded=TRUE)
perspContour(Z, M, ...,
             nlevels=10, levels=pretty(range(Z), nlevels),
             occluded=TRUE)

Value

Same as the return value from

points

or segments.

Details

After a surface has been plotted in a perspective view, these functions can be used to draw points or lines on the surface.

The user should already have called persp.im to display the perspective view of the surface Z and to obtain the perspective matrix M by typing M <- persp(Z, ...). The points and lines will be drawn in their correct three-dimensional position according to the same perspective.

If occluded=TRUE (the default), then the surface is treated as if it were opaque. The code will draw only those points and lines which are visible from the viewer's standpoint, and not obscured by other parts of the surface lying closer to the viewer. The user should already have called persp.im in the form M <- persp(Z, visible=TRUE, ...) to compute the visibility information.

If occluded=FALSE, then the surface is treated as if it were transparent. All the specified points and lines will be drawn on the surface.

See Also

persp.im

Examples

  M <- persp(bei.extra$elev, colmap=terrain.colors(128),
             apron=TRUE, theta=-30, phi=20,
             zlab="Elevation", main="", 
             expand=6, visible=TRUE, shade=0.3)

  perspContour(bei.extra$elev, M=M, col="pink", nlevels=12)
  perspPoints(bei, Z=bei.extra$elev, M=M, pch=16, cex=0.3, col="chartreuse")