# equation2function: Turn a Character String of the Right-Hand Side of an Equation... In paleotree: Paleontological and Phylogenetic Analyses of Evolution

## Description

`equation2function` converts the right-hand side of an equation that can be written as a single line (like the right-hand side of an object of class `formula`) and creates an R function which calls the variables within as arguments and returns values consistent with the parameters of the input equation as written.

## Usage

 `1` ```equation2function(equation, envir = parent.frame(), notName = "XXXXXXXXXXX") ```

## Arguments

 `equation` The right-hand-side (RHS) of an equation, given as a character string. If not of type character, `equation2function` attempts to coerce `equation` to type character and fails if it cannot. `envir` The environment the resulting function will be evaluated in. See `as.function`. `notName` A useless string used simply as a placeholder in turning `equation` into a function, which should not match any actual variable in `equation`. Only supplied as an argument in case any

## Details

This simple little function is rather 'hacky' but seems to get the job done, for a functionality that does not seem to be otherwise exist elsewhere in R.

## Value

A function, with named blank (i.e. no default value) arguments.

David W. Bapst

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13``` ```# some simple examples foo<-equation2function("x+y") foo foo(x=4,y=0.1) foo<-equation2function("x+2*sqrt(2*y+3)^2") foo foo(x=4,y=0.1) # what about weird long argument names and spaces foo<-equation2function("stegosaur + 0.4 * P") foo foo(stegosaur=5,P=0.3) ```

paleotree documentation built on Nov. 17, 2017, 5:11 a.m.