# nlCheckPars: Check Parameters of the Normal Laplace Distribution In NormalLaplace: The Normal Laplace Distribution

 nlCheckPars R Documentation

## Check Parameters of the Normal Laplace Distribution

### Description

Given a set of parameters for the normal Laplace distribution, the functions checks the validity of each parameter and if they and if they correspond to the boundary cases.

### Usage

``````nlCheckPars(param)
``````

### Arguments

 `param` Numeric. Parameter values for the normal Laplace distribution.

### Details

The vector `param` takes the form `c(mu, sigma, alpha, beta)`.

If any of `sigma`, `alpha` or `beta` is negative or NA, an error is returned.

### Author(s)

David Scott d.scott@auckland.ac.nz, Simon Potter

### References

William J. Reed. (2006) The Normal-Laplace Distribution and Its Relatives. In Advances in Distribution Theory, Order Statistics and Inference, pp. 61–74. Birkhäuser, Boston.

### Examples

``````## Correct parameters
nlCheckPars(c(0, 1.5, 1, 2))
nlCheckPars(c(3, 1, 1.5, 2))

## Incorrect parameters, each error providing a different error message
nlCheckPars(c(2, -1, 1, 1))          # invalid sigma
nlCheckPars(c(2, 1, -1, 2))          # invalid alpha
nlCheckPars(c(0, 1, 2, -1))          # invalid beta
nlCheckPars(c(0, -0.01, -0.1, 1))    # sigma and alpha incorrect
nlCheckPars(c(2, -0.5, 1, -0.2))     # sigma and beta incorrect
nlCheckPars(c(1, 1, -0.2, -1))       # alpha and beta incorrect
nlCheckPars(c(0, -0.1, -0.2, -0.3))  # all three parameters erroneous
nlCheckPars(c(0.5, NA, 1, 1))        # NA introduced
nlCheckPars(c(-1, 1, 1))             # incorrect number of parameters
``````

NormalLaplace documentation built on Nov. 26, 2023, 1:07 a.m.