R: One-truncated Positive-Poisson Distribution

Otpospois {VGAM} | R Documentation

## One-truncated Positive-Poisson Distribution

### Description

Density, distribution function, quantile function, and random generation for the one-truncated positive-Poisson distribution.

### Usage

    dotpospois(x, lambda, log = FALSE)
    potpospois(q, lambda, log.p = FALSE)
    qotpospois(p, lambda)
    rotpospois(n, lambda)

### Arguments

`x, q, p, n` | Same as `Pospois`.
`lambda, log, log.p` | Same as `Pospois`.

### Details

The one-truncated positive-Poisson is a Poisson distribution but with the probability of a one and a zero being 0. That is, its support is 2, 3, .... The other probabilities are scaled to add to unity. Some more details are given in `pospoisson`.

### Value

`dotpospois` gives the density, `potpospois` gives the distribution function, `qotpospois` gives the quantile function, and `rotpospois` generates random deviates.

### Note

Given some response data, the VGAM family function `otpospoisson` estimates the parameter `lambda`.

### Author(s)

T. W. Yee

### See Also

`otpospoisson`, `Pospois`, `Oipospois`.

### Examples

    dotpospois(1:20, 0.5)
    rotpospois(20, 0.5)

    ## Not run:  lambda <- 4; x <- 1:10
    plot(x, dotpospois(x, lambda = lambda), type = "h", ylim = 0:1,
         sub = "lambda=4", las = 1, col = "blue", ylab = "Probability",
         main = "1-truncated positive-Poisson distribution: blue=PMF; orange=CDF")
    lines(x + 0.1, potpospois(x, lambda = lambda), col = "orange", lty = 3, type = "h")
    ## End(Not run)

[Package VGAM version 1.1-3 Index]