nppois function

Class `nppois'

Class `nppois'

Class nppois is used to store data that will be processed as those of a nonparametric Poisson mixture.

nppois(v, w=1)
rnppois(n, mix=disc(1))
## S3 method for class 'nppois'
plot(x, mix, beta, col="red", add=FALSE,
    components=TRUE, main="nppois", lwd=1, lty=1, xlab="Data",
    ylab="Density", ...)

Arguments

  • v: a numeric vector that stores the values of a sample.
  • w: a numeric vector that stores the corresponding weights/frequencies of the observations.
  • n: the sample size.
  • x: an object of class nppois.
  • mix: an object of class disc.
  • beta: the structural parameter, which is not really needed for the Poisson mixture.
  • col: the color of the density curve to be plotted.
  • add: if FALSE, creates a new plot; if TRUE, adds the plot to the existing one.
  • components: if TRUE, also show the support points and mixing proportions.
  • main, lwd, lty, xlab, ylab: arguments for graphical parameters (see par).
  • ...: arguments passed on to function plot.

Details

Function nppois creates an object of class nppois, given values and weights/frequencies.

Function rnppois generates a random sample from a Poisson mixture and saves the data as an object of class nppois.

Function plot.nppois plots the Poisson mixture.

When components=TRUE, the support points are shown on the horizontal line of density 0. The component density curves, weighted appropriately, are also shown.

Examples

mix = disc(pt=c(1,4), pr=c(0.3,0.7))
x = rnppois(200, mix)
plot(x, mix)

References

Wang, Y. (2007). On fast computation of the non-parametric maximum likelihood estimate of a mixing distribution. Journal of the Royal Statistical Society, Ser. B, 69 , 185-198.

See Also

nnls, cnm, cnmms, plot.nspmix.

Author(s)

Yong Wang yongwang@auckland.ac.nz

nspmix packageRead PDF manual