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VGAM (version 1.1-13)

niters: Number of Iterations

Description

Extracts the number of IRLS iterations performed for a VGLM object.

Usage

niters(object, ...)
niters.vlm(object, history = FALSE, ...)

Value

A non-negative integer by default. If history = TRUE then a matrix.

Arguments

object

A vglm object. Currently a vgam object is accepted but the correct value is not returned.

history

Logical, if TRUE it returns the convergence history with respect to the criterion, e.g., vglm.control()[["criterion"]].

...

Currently unused.

Details

The number of iteratively reweighted least squares (IRLS) iterations needed for convergence (or non-convergence) does say something about the model. Since Fisher scoring has a linear convergence rate in general, it should take no more than 10 iterations, say, for successful convergence. Much more indicates potential problems, e.g., a large disagreement between data and the specified model.

See Also

vglm, vglm.control.

Examples

Run this code
fit <- vglm(rpois(9, 2) ~ 1, poissonff, crit = "c")
niters(fit)
niters(fit, history = TRUE)

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