# Class "NelderMead" of Nelder-Mead optimizers and its Generator

### Description

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.

### Usage

1 |

### Arguments

`...` |
Argument list (see Note below). |

### Methods

`NelderMead$new(lower, upper, xst, x0, xt)`

Create a
new `NelderMead`

object

### Extends

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

.

### 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.

### References

Based on code in the NLopt collection.

### See Also

`Nelder_Mead`

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

, `nlmer`

### Examples

1 | ```
showClass("NelderMead")
``` |