# frair methods

### Description

Documentation for methods for class frfit

### Usage

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### Arguments

`x ` |
Output from a call to |

`xlab ` |
Label for the x-axis. |

`ylab ` |
Label for the y-axis. |

`tozero ` |
A logical. Should the line be drawn to the origin? See Details. |

`... ` |
Other items passed to underlying functions. |

### Details

This documents standard methods for FRAIR objects of class `frfit`

. However, because standard naming conventions have been used, some undocumented utility functions might also work (e.g. `coefficients`

)

`lines`

only adds lines to an existing plot, so an active graphics device needs to be present. `lines`

draws the curve for the fitted response evaluated at values:

`seq(from=min(x$x), to=max(x$x), length.out = 50)`

or

`seq(from=0, to=max(x$x), length.out = 50)`

if `tozero`

is TRUE.

If the supplied function is undefined at zero (and `tozero`

is TRUE), then lines will plot lines to a small, non-zero number (1e-04) instead (with a warning). Clearly the intention here is to provide a nice-looking representation of the fitted curve and it is up to the user to determine *why* their desired curve is undefined at zero.

### Author(s)

Daniel Pritchard

### See Also

`frair_fit`

, `lines`

.

### Examples

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