is.formula

<p>Is a formula?
Checks if argument is a formula</p>

internal

A set of tools that solves a common set of problems: you need
to break a big problem down into manageable pieces, operate on each
piece and then put all the pieces back together.  For example, you
might want to fit a model to each spatial location or time point in
your study, summarise data by panels or collapse high-dimensional
arrays to simpler summary statistics. The development of 'plyr' has
been generously supported by 'Becton Dickinson'.

Hadley Wickham

is.formula: Is a formula? Checks if argument is a formula

Description

Usage

Arguments