bzip.a {bzinb} R Documentation

## The bivariate zero-inflated Poisson distribution (A)

### Description

random generation (`rbzip.a`), maximum likelihood estimation (`bzip.a`), and log-likelihood. (`lik.bzip.a`) for the bivariate zero-inflated Poisson (A) distribution with parameters equal to `(m0, m1, m2, p)`.

### Usage

```lik.bzip.a(xvec, yvec, m0, m1, m2, p, param = NULL)

rbzip.a(n, m0, m1, m2, p, param = NULL)

bzip.a(xvec, yvec, tol = 1e-06, initial = NULL, showFlag = FALSE)
```

### Arguments

 `xvec, yvec` a pair of BZIP (A) random vectors. nonnegative integer vectors. If not integers, they will be rounded to the nearest integers. `m0, m1, m2` mean parameters of the Poisson variables. must be positive. `p` zero-inflation probability `param` a vector of parameters (`(m0, m1, m2, p)`). Either `param` or individual parameters (`m0, m1, m2, p`) need to be provided. `n` number of observations. `tol` tolerance for judging convergence. `tol = 1e-8` by default. `initial` starting value of param for EM algorithm, a vector of nine values. `showFlag` if `TRUE`, the updated parameter estimates for each iteration are printed out. If a positive integer, the updated parameter estimates for iterations greater than `showFlag` are printed out.

### Value

• `rbzip.a` gives a pair of random vectors following BZIP (A) distribution.

• `bzip.a` gives the maximum likelihood estimates of a BZIP (A) pair.

• `lik.bzip.a` gives the log-likelihood of a set of parameters for a BZIP (A) pair.

### Author(s)

Hunyong Cho, Chuwen Liu, Jinyoung Park, and Di Wu

### References

Cho, H., Liu, C., Preisser, J., and Wu, D. (In preparation), "A bivariate zero-inflated negative binomial model for identifying underlying dependence"

Li, C. S., Lu, J. C., Park, J., Kim, K., Brinkley, P. A., & Peterson, J. P. (1999). Multivariate zero-inflated Poisson models and their applications. Technometrics, 41, 29-38.

### Examples

```# generating a pair of random vectors
set.seed(1)
data1 <- rbzip.a(n = 20, m0 = 1, m1 = 1, m2 = 1, p = 0.5)

lik.bzip.a(xvec = data1[, 1], yvec = data1[ ,2],
m0 = 1, m1 = 1, m2 = 1, p = 0.5)

bzip.a(xvec = data1[,1], yvec = data1[,2], showFlag = FALSE)

```

[Package bzinb version 1.0.4 Index]