SDraw (version 2.1.13)

maxU: Maximum integer used in the BAS routines

Description

A function that returns the maximum integer used to construct the random-start Halton sequences. By redefining this function and placing in the .GlobalEnv environment, the user can change the maximum integer and hence the number of possible BAS samples.

Usage

maxU()

Value

10e7 or 100,000,000

Details

CAUTION: The following comment is intended for those who wish to simulate or study statistical properties of BAS, and want to completely enumerate the sample space. Don't do this if you are actually drawing a sample.

To change maxU, redefine maxU() in .GlobalEnv. For example, maxU <- function() 4. There are only 25 possible 2D Halton starts in this case. Random starts are = (0,1,2,3,4) X (0,1,2,3,4).

In general, all.possible.starts = expand.grid(x=0:maxU(),y=0:maxU()))

Number of possible BAS samples is less than or equal to (maxU()+1)^2 because the first sample point is required to land in a valid polygon. So, starts that do not land in polygon are discarded.

References

Robertson, B.L., J. A. Brown, T. L. McDonald, and P. Jaksons (2013) "BAS: Balanced Acceptance Sampling of Natural Resources", Biometrics, v69, p. 776-784.

See Also

bas.line, bas.point, bas.polygon

Examples

# NOT RUN {
# A 2D random-start Halton sequence, length 10, bases c(2,3).
u <- c( floor((maxU()+1)*runif(1)), floor((maxU()+1)*runif(1)))
halt.pts <- halton(10,dim=2,start=u,bases=c(2,3))


# }