comparePred | R Documentation |

Predicted values are obtained at the specified values of
`primary`

for each object. If either `object1`

or
`object2`

have a grouping structure
(i.e. `getGroups(object)`

is not `NULL`

), predicted values
are obtained for each group. When both objects determine groups, the
group levels must be the same. If other covariates besides
`primary`

are used in the prediction model, their group-wise averages
(numeric covariates) or most frequent values (categorical covariates)
are used to obtain the predicted values. The original observations are
also included in the returned object.

```
comparePred(object1, object2, primary, minimum, maximum,
length.out, level, ...)
```

`object1,object2` |
fitted model objects, from which predictions can
be extracted using the |

`primary` |
an optional one-sided formula specifying the primary
covariate to be used to generate the augmented predictions. By
default, if a covariate can be extracted from the data used to generate
the objects (using |

`minimum` |
an optional lower limit for the primary
covariate. Defaults to |

`maximum` |
an optional upper limit for the primary
covariate. Defaults to |

`length.out` |
an optional integer with the number of primary covariate values at which to evaluate the predictions. Defaults to 51. |

`level` |
an optional integer specifying the desired prediction level. Levels increase from outermost to innermost grouping, with level 0 representing the population (fixed effects) predictions. Only one level can be specified. Defaults to the innermost level. |

`...` |
some methods for the generic may require additional arguments. |

a data frame with four columns representing, respectively, the values
of the primary covariate, the groups (if `object`

does not have a
grouping structure, all elements will be `1`

), the predicted or
observed values, and the type of value in the third column: the
objects' names are used to classify the predicted values and
`original`

is used for the observed values. The returned object
inherits from classes `comparePred`

and `augPred`

.

This function is generic; method functions can be written to handle
specific classes of objects. Classes which already have methods for
this function include: `gls`

, `lme`

, and `lmList`

.

JosÃ© Pinheiro and Douglas Bates bates@stat.wisc.edu

`augPred`

, `getGroups`

```
fm1 <- lme(distance ~ age * Sex, data = Orthodont, random = ~ age)
fm2 <- update(fm1, distance ~ age)
comparePred(fm1, fm2, length.out = 2)
```

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.