spatstat.geom: perspPoints – R documentation

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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)

perspLines(x, y = NULL, ..., Z, M)

perspSegments(x0, y0 = NULL, x1 = NULL, y1 = NULL, ..., Z, M)

perspContour(Z, M, ...,
             nlevels=10, levels=pretty(range(Z), nlevels))

Arguments

`x,y`	Spatial coordinates, acceptable to `xy.coords`, for the points or lines on the horizontal plane.
`Z`	Pixel image (object of class `"im"`) specifying the surface heights.
`M`	Projection matrix returned from `persp.im` when `Z` was plotted.
`...`	Graphical arguments passed to `points`, `lines` or `segments` to control the drawing.
`x0,y0,x1,y1`	Spatial coordinates of the line segments, on the horizontal plane. Alternatively `x0` can be a line segment pattern (object of class `"psp"`) and `y0,x1,y1` can be `NULL`.
`nlevels`	Number of contour levels
`levels`	Vector of heights of contours.

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 in the form M <- persp(Z, visible=TRUE, ...) to display the perspective view of the surface Z.

Only points and lines which are visible from the viewer's standpoint will be drawn.

Value

Same as the return value from points or segments.

Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner r.turner@auckland.ac.nz and Ege Rubak rubak@math.aau.dk

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")

spatstat.geom

Geometrical Functionality of the 'spatstat' Family

v2.1-0

GPL (>= 2)

Authors

Adrian Baddeley [aut, cre], Rolf Turner [aut], Ege Rubak [aut], Tilman Davies [ctb], Ute Hahn [ctb], Abdollah Jalilian [ctb], Sebastian Meyer [ctb], Suman Rakshit [ctb], Dominic Schuhmacher [ctb], Rasmus Waagepetersen [ctb]

Initial release

2021-04-15