popbio (version 2.8)

stretchbetaval: Stretched beta-distributed random numbers

Description

Generate a stretched beta number with mean, standard deviation, minimum and maximum values and CDF value for bounded fertility estimates

Usage

stretchbetaval(mn, std, minb, maxb, fx)

Value

Returns a stretched beta number with mean mn, standard deviation std, minimum and maximum values (minb, maxb) and CDF value fx.

Arguments

mn

mean of a fertility rate

std

standard deviation

minb

minimum value

maxb

maximum value

fx

Cumulative Distribution Function value

Author

Adapted to R by Patrick Nantel, 11 July 2005.

Details

converted Matlab code from Box 8.5 in Morris and Doak (2002)

References

Morris, W. F., and D. F. Doak. 2002. Quantitative conservation biology: Theory and practice of population viability analysis. Sinauer, Sunderland, Massachusetts, USA.

See Also

betaval

Examples

stretchbetaval(3, 1.2, 1, 20, runif(1))
# Generates stretchbeta random
# fertilities for a population of 1000 mature individuals (Ni) with mean
# fertility (f) of 3.0 and inter-individual variance in fertility (varF) of 1.5.
Ni   <- 1000
f    <- 2.5
varF <- 1
fmin <- 1
fmax <- 5
rndfert<-numeric(Ni)
for(i in 1:Ni) rndfert[i] <- stretchbetaval(f, sqrt(varF), fmin, fmax, runif(1)) 
hist(rndfert,20, main="Stretched beta-distributed random fertilities",
 xlab="Fertility rate", , col="blue")