angles.psp {spatstat.geom}

Orientation Angles of Line Segments

Description

Computes the orientation angle of each line segment in a line segment pattern.

Usage

  angles.psp(x, directed=FALSE)

Arguments

x

A line segment pattern (object of class "psp").

directed

Logical flag. See details.

Details

For each line segment, the angle of inclination to the x-axis (in radians) is computed, and the angles are returned as a numeric vector.

If directed=TRUE, the directed angle of orientation is computed. The angle respects the sense of direction from (x0,y0) to (x1,y1). The values returned are angles in the full range from -\pi to \pi. The angle is computed as atan2(y1-y0,x1-x0). See atan2.

If directed=FALSE, the undirected angle of orientation is computed. Angles differing by \pi are regarded as equivalent. The values returned are angles in the range from 0 to \pi. These angles are computed by first computing the directed angle, then adding \pi to any negative angles.

Value

Numeric vector.

Author(s)

Adrian Baddeley [e-mail]

and Rolf Turner [e-mail]

See Also

psp, marks.psp, summary.psp, midpoints.psp, lengths_psp, endpoints.psp, extrapolate.psp.

Examples

  a <- psp(runif(10), runif(10), runif(10), runif(10), window=owin())
  b <- angles.psp(a)