# NelderMead-class

##### Class `"NelderMead"`

of Nelder-Mead optimizers and its Generator

Class `"NelderMead"`

is a reference class for a Nelder-Mead
simplex optimizer allowing box constraints on the parameters and using
reverse communication.

The `NelderMead()`

function conveniently generates such objects.

- Keywords
- classes

##### Usage

`NelderMead(...)`

##### Arguments

- …
Argument list (see Note below).

##### Note

This is the default optimizer for the second stage of
`glmer`

and `nlmer`

fits. We
found that it was more reliable and often faster than
more sophisticated optimizers.

Arguments to `NelderMead()`

and the `new`

method must
be named arguments:

- lower
numeric vector of lower bounds - elements may be

`-Inf`

.- upper
numeric vector of upper bounds - elements may be

`Inf`

.- xst
numeric vector of initial step sizes to establish the simplex - all elements must be non-zero.

- x0
numeric vector of starting values for the parameters.

- xt
numeric vector of tolerances on the parameters.

##### Methods

##### Extends

All reference classes extend and inherit methods from
`"'>envRefClass"`

.

##### References

Based on code in the NLopt collection.

##### See Also

`Nelder_Mead`

, the typical “constructor”.
Further, `glmer`

, `nlmer`

##### Examples

```
# NOT RUN {
showClass("NelderMead")
# }
```

*Documentation reproduced from package lme4, version 1.1-21, License: GPL (>= 2)*