R: Generic function for pointwise log-likelihood

log_lik {rstantools} | R Documentation

## Generic function for pointwise log-likelihood

### Description

We define a new function `log_lik()` rather than a `stats::logLik()` method because (in addition to the conceptual difference) the documentation for `logLik()` states that the return value will be a single number, whereas `log_lik()` returns a matrix. See the log_lik.stanreg() method in the rstanarm package for an example of defining a method.

### Usage

    log_lik(object, ...)

### Arguments

`object` | The object to use.
`...` | Arguments passed to methods. See the methods in the rstanarm package for examples.

### Value

`log_lik()` methods should return a S by N matrix, where S is the size of the posterior sample (the number of draws from the posterior distribution) and N is the number of data points.

### See Also

- The rstanarm package (mc-stan.org/rstanarm) for example methods (CRAN, GitHub).

- Guidelines and recommendations for developers of R packages interfacing with Stan and a demonstration getting a simple package working can be found in the vignettes included with rstantools and at mc-stan.org/rstantools/articles.

### Examples

    # See help("log_lik", package = "rstanarm")

[Package rstantools version 2.0.0 Index]