Coef {VGAM} | R Documentation

## Computes Model Coefficients and Quantities

### Description

`Coef` is a generic function which computes model coefficients from objects returned by modelling functions. It is an auxiliary function to `coef` that enables extra capabilities for some specific models.

### Usage

    Coef(object, ...)

### Arguments

`object` | An object for which the computation of other types of model coefficients or quantities is meaningful.
`...` | Other arguments fed into the specific methods function of the model.

### Details

This function can often be useful for `vglm` objects with just an intercept term in the RHS of the formula, e.g., `y ~ 1`. Then often this function will apply the inverse link functions to the parameters. See the example below.

For reduced-rank VGLMs, this function can return the A, C matrices, etc.

For quadratic and additive ordination models, this function can return ecological meaningful quantities such as tolerances, optima, maxima.

### Value

The value returned depends specifically on the methods function invoked.

### Warning

This function may not work for all VGAM family functions. You should check your results on some artificial data before applying it to models fitted to real data.

### Author(s)

Thomas W. Yee

### References

Yee, T. W. and Hastie, T. J. (2003) Reduced-rank vector generalized linear models. Statistical Modelling, 3, 15–41.

### See Also

`coef`, `Coef.vlm`, `Coef.rrvglm`, `Coef.qrrvglm`.

### Examples

    set.seed(123)
    nn = 1000
    y = rbeta(nn, shape1=1, shape2=3) # Original scale
    # parameters are estimated on a log scale:
    fit = vglm(y ~ 1, betaff, tr=TRUE, crit="c") # intercept-only model
    coef(fit, matrix=TRUE) #  log scale
    Coef(fit) # On the original scale

[Package VGAM version 0.7-9 Index]