runifpoint

Generate N Uniform Random Points

Generate a random point pattern containing $n$ independent uniform random points.

Usage

runifpoint(n, win=owin(c(0,1),c(0,1)), giveup=1000)

Details

This function generates n independent random points, uniformly distributed in the window win. (For nonuniform distributions, see rpoint.)

The algorithm depends on the type of window, as follows:

• Ifwinis a rectangle then$n$independent random points, uniformly distributed in the rectangle, are generated by assigning uniform random values to their cartesian coordinates.
• Ifwinis a binary image mask, then a random sequence of pixels is selected (usingsample) with equal probabilities. Then for each pixel in the sequence we generate a uniformly distributed random point in that pixel.
• Ifwinis a polygonal window, the algorithm uses the rejection method. It finds a rectangle enclosing the window, generates points in this rectangle, and tests whether they fall in the desired window. It gives up whengiveup * ntests have been performed without yieldingnsuccesses.

See Also

ppp.object, owin.object, rpoispp, rpoint

Aliases

• runifpoint

Examples

# 100 random points in the unit square
 pp <- runifpoint(100)
 # irregular window
 data(letterR)
 # polygonal
 pp <- runifpoint(100, letterR)
 # binary image mask
 pp <- runifpoint(100, as.mask(letterR))