runifpoint
From spatstat v1.23-3
by Adrian Baddeley
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)
Arguments
- n
- Number of points.
- win
- Window in which to simulate the pattern.
An object of class
"owin"
or something acceptable toas.owin
. - giveup
- Number of attempts in the rejection method after which the algorithm should stop trying to generate new points.
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:
- If
win
is a rectangle then$n$independent random points, uniformly distributed in the rectangle, are generated by assigning uniform random values to their cartesian coordinates. - If
win
is 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. - If
win
is 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 * n
tests have been performed without yieldingn
successes.
Value
- The simulated point pattern (an object of class
"ppp"
).
See Also
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))
Community examples
Looks like there are no examples yet.