model.tables {stats} | R Documentation

## Compute Tables of Results from an Aov Model Fit

### Description

Computes summary tables for model fits, especially complex `aov` fits.

### Usage

    model.tables(x, ...)

    ## S3 method for class 'aov':
    model.tables(x, type = "effects", se = FALSE, cterms, ...)

    ## S3 method for class 'aovlist':
    model.tables(x, type = "effects", se = FALSE, ...)

### Arguments

`x` | a model object, usually produced by `aov`
`type` | type of table: currently only `"effects"` and `"means"` are implemented.
`se` | should standard errors be computed?
`cterms` | A character vector giving the names of the terms for which tables should be computed. The default is all tables.
`...` | further arguments passed to or from other methods.

### Details

For `type = "effects"` give tables of the coefficients for each term, optionally with standard errors.

For `type = "means"` give tables of the mean response for each combinations of levels of the factors in a term.

### Value

An object of class `"tables.aov"`, as list which may contain components

`tables` | A list of tables for each requested term.
`n` | The replication information for each term.
`se` | Standard error information.

### Warning

The implementation is incomplete, and only the simpler cases have been tested thoroughly.

Weighted `aov` fits are not supported.

### See Also

`aov`, `proj`, `replications`, `TukeyHSD`, `se.contrast`

### Examples

    ## From Venables and Ripley (2002) p.165.
    N <- c(0,1,0,1,1,1,0,0,0,1,1,0,1,1,0,0,1,0,1,0,1,1,0,0)
    P <- c(1,1,0,0,0,1,0,1,1,1,0,0,0,1,0,1,1,0,0,1,0,1,1,0)
    K <- c(1,0,0,1,0,1,1,0,0,1,0,1,0,1,1,0,0,0,1,1,1,0,1,0)
    yield <- c(49.5,62.8,46.8,57.0,59.8,58.5,55.5,56.0,62.8,55.8,69.5,
    55.0, 62.0,48.8,45.5,44.2,52.0,51.5,49.8,48.8,57.2,59.0,53.2,56.0)

    npk <- data.frame(block=gl(6,4), N=factor(N), P=factor(P),
                      K=factor(K), yield=yield)
    npk.aov <- aov(yield ~ block + N*P*K, npk)
    model.tables(npk.aov, "means", se=TRUE)

    ## as a test, not particularly sensible statistically
    options(contrasts=c("contr.helmert", "contr.treatment"))
    npk.aovE <- aov(yield ~  N*P*K + Error(block), npk)
    model.tables(npk.aovE,  se=TRUE)
    model.tables(npk.aovE, "means")

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