plot.profile.nls {stats} | R Documentation |

## Plot a `profile.nls`

Object

### Description

Displays a series of plots of the profile t function and interpolated
confidence intervals for the parameters in a nonlinear regression
model that has been fit with `nls`

and profiled with
`profile.nls`

.

### Usage

```
## S3 method for class 'profile.nls'
plot(x, levels, conf = c(99, 95, 90, 80, 50)/100,
absVal = TRUE, ylab = NULL, lty = 2, ...)
```

### Arguments

`x` |
an object of class |

`levels` |
levels, on the scale of the absolute value of a t
statistic, at which to interpolate intervals. Usually |

`conf` |
a numeric vector of confidence levels for profile-based
confidence intervals on the parameters.
Defaults to |

`absVal` |
a logical value indicating whether or not the plots
should be on the scale of the absolute value of the profile t.
Defaults to |

`lty` |
the line type to be used for axis and dropped lines. |

`ylab` , `...` |
other arguments to the |

### Details

The plots are produced in a set of hard-coded colours, but as these
are coded by number their effect can be changed by setting the
`palette`

. Colour 1 is used for the axes and 4 for the
profile itself. Colours 3 and 6 are used for the axis line at zero and
the horizontal/vertical lines dropping to the axes.

### Author(s)

Douglas M. Bates and Saikat DebRoy

### References

Bates, D.M. and Watts, D.G. (1988),
*Nonlinear Regression Analysis and Its Applications*,
Wiley (chapter 6)

### See Also

### Examples

```
require(graphics)
# obtain the fitted object
fm1 <- nls(demand ~ SSasympOrig(Time, A, lrc), data = BOD)
# get the profile for the fitted model
pr1 <- profile(fm1, alphamax = 0.05)
opar <- par(mfrow = c(2,2), oma = c(1.1, 0, 1.1, 0), las = 1)
plot(pr1, conf = c(95, 90, 80, 50)/100)
plot(pr1, conf = c(95, 90, 80, 50)/100, absVal = FALSE)
mtext("Confidence intervals based on the profile sum of squares",
side = 3, outer = TRUE)
mtext("BOD data - confidence levels of 50%, 80%, 90% and 95%",
side = 1, outer = TRUE)
par(opar)
```

*stats*version 4.4.0 Index]