pdgradient {lme4} | R Documentation

## Evaluated the pdmatrix gradient

### Description

This function is generic. It returns the gradient of the positive definite matrix represented by `x` with respect to the parameters of `x`.

### Usage

    pdgradient(x)

### Arguments

`x` | An object of a suitable class, usually one of the classes that inherit from `pdMat`.

### Value

A numeric array of dimension `c(dim(x), length(coef(x)))` that is the gradient of the `pdmatrix` represented by `x` with respect to the parameters of `x`.

### Methods

x = pdIdent
  gradient for the `pdIdent` class
x = pdLogChol
  gradient for the `pdLogChol` class
x = pdMat
  gradient for the `pdMat` class, implemented using `pdgradNumeric`

### Author(s)

Douglas Bates bates@stat.wisc.edu and Saikat DebRoy saikat@stat.wisc.edu

### See Also

`pdgradNumeric`

### Examples

[Package Contents]