Description Usage Arguments Details Value Note Author(s) References See Also Examples

Find models that are ‘nested’ within each model in the model selection table.

1 |

`x` |
a |

`indices` |
if omitted or |

`rank` |
the name of the column with the ranking values (defaults to
the one before “delta”). Only used if |

In model comparison, a model is said to be “nested” within another model if it contains a subset of parameters of the latter model, but does not include other parameters (e.g. model ‘A+B’ is nested within ‘A+B+C’ but not ‘A+C+D’).

This function can be useful in a model selection approach suggested by Richards (2008), in which more complex variants of any model with a lower IC value are excluded from the candidate set.

A vector of length equal to the number of models (table rows).

If `indices = "none"`

(the default), it is a vector of logical
values where *i*-th element is `TRUE`

if any model(s) higher up in
the table are nested within it (i.e. if simpler models have lower IC pointed
by `rank`

).

For `indices`

other than `"none"`

, the function returns a list of
vectors of numeric indices or names of models nested within each
*i*-th model.

This function determines nesting based only on fixed model terms, within groups of
models sharing the same ‘varying’ parameters (see `dredge`

and
example in `Beetle`

).

Kamil Bartoń

Richards, S. A., Whittingham, M. J., Stephens, P. A (2011). Model selection and
model averaging in behavioural ecology: the utility of the IT-AIC framework.
*Behavioral Ecology and Sociobiology*, 65: 77-89

Richards, S. A (2008) Dealing with overdispersed count data in applied
ecology. *Journal of Applied Ecology* 45: 218–227

1 2 3 4 5 6 7 8 9 10 11 12 13 14 | ```
fm <- lm(y ~ X1 + X2 + X3 + X4, data = Cement, na.action = na.fail)
ms <- dredge(fm)
# filter out overly complex models according to the
# "nesting selection rule":
subset(ms, !nested(.)) # dot represents the ms table object
# print model "4" and all models nested within it
nst <- nested(ms, indices = "row")
ms[c("4", nst[["4"]])]
ms$nested <- sapply(nst, paste, collapse = ",")
ms
``` |

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.