# mvformula: Model Formulae for Multivariate Abundance Data In mvabund: Statistical Methods for Analysing Multivariate Abundance Data

 mvformula R Documentation

## Model Formulae for Multivariate Abundance Data

### Description

`mvformula` is a method to create an object of class `mvformula`
`as.mvformula` is a function to turn a formula into a `mvformula`
`is.mvformula` tests if its argument is a `mvformula` object. `mvformula` is a class of objects for which special-purpose plotting and regression functions have been written in the `mvabund-package`. The above are useful preliminary functions before analysing data using the special-purpose functions. These new functions were written specially for the analysis of multivariate abundance data in ecology, hence the title 'mvabund'.

### Usage

```mvformula(x)

as.mvformula(x)
is.mvformula(x)
```

### Arguments

 `x` an R object.

### Details

`mvformula` is a method to create an object of class `mvformula` If the response of the resulting formula is not a `mvabund` object, a warning will be printed. `as.mvformula` is a function to turn a formula into a `mvformula` if the response in x is a data.frame or an unsuitable object the conversion will fail.

### Value

a formula mvabund for `mvformula` and `as.mvformula` a logical value indicating whether `x` is a `mvformula` object

### Author(s)

Ulrike Naumann and David Warton <David.Warton@unsw.edu.au>.

`mvabund`. `manylm`.

### Examples

```require(graphics)

data(spider)
spiddat <- mvabund(spider\$abund)
X=as.matrix(spider\$x)

## Create a formula for multivariate abundance data:
foo <- mvformula( spiddat~X )

## Check whether foo is a mvformula:
is.mvformula(foo)

## Plot a mvformula:
plot(foo)

```

mvabund documentation built on March 18, 2022, 7:25 p.m.