# plot.betareg

##### Diagnostic Plots for betareg Objects

Various types of standard diagnostic plots can be produced, involving various types of residuals, influence measures etc.

- Keywords
- regression

##### Usage

```
# S3 method for betareg
plot(x, which = 1:4,
caption = c("Residuals vs indices of obs.", "Cook's distance plot",
"Generalized leverage vs predicted values", "Residuals vs linear predictor",
"Half-normal plot of residuals", "Predicted vs observed values"),
sub.caption = paste(deparse(x$call), collapse = "\n"), main = "",
ask = prod(par("mfcol")) < length(which) && dev.interactive(),
…, type = "sweighted2", nsim = 100, level = 0.9)
```

##### Arguments

- x
fitted model object of class

`"betareg"`

.- which
numeric. If a subset of the plots is required, specify a subset of the numbers

`1:6`

.- caption
character. Captions to appear above the plots.

- sub.caption
character. Common title-above figures if there are multiple.

- main
character. Title to each plot in addition to the above

`caption`

.- ask
logical. If

`TRUE`

, the user is asked before each plot.- …
other parameters to be passed through to plotting functions.

- type
character indicating type of residual to be used, see

`residuals.betareg`

.- nsim
numeric. Number of simulations in half-normal plots.

- level
numeric. Confidence level in half-normal plots.

##### Details

The `plot`

method for `betareg`

objects produces various types
of diagnostic plots. Most of these are standard for regression models and involve
various types of residuals, influence measures etc. See Ferrari and Cribari-Neto (2004)
for a discussion of some of these displays.

The `which`

argument can be used to select a subset of currently six supported
types of displays. The corresponding element of `caption`

contains a brief
description. In some more detail, the displays are: Residuals (as selected by
`type`

) vs indices of observations (`which = 1`

). Cook's distances
vs indices of observations (`which = 2`

). Generalized leverage vs
predicted values (`which = 3`

). Residuals vs linear predictor (`which = 4`

).
Half-normal plot of residuals (`which = 5`

), which is obtained using a simulation
approach. Predicted vs observed values (`which = 6`

).

##### References

Cribari-Neto, F., and Zeileis, A. (2010). Beta Regression in R.
*Journal of Statistical Software*, **34**(2), 1--24.
http://www.jstatsoft.org/v34/i02/.

Ferrari, S.L.P., and Cribari-Neto, F. (2004).
Beta Regression for Modeling Rates and Proportions.
*Journal of Applied Statistics*, **31**(7), 799--815.

##### See Also

##### Examples

```
# NOT RUN {
data("GasolineYield", package = "betareg")
gy <- betareg(yield ~ gravity + pressure + temp10 + temp, data = GasolineYield)
par(mfrow = c(3, 2))
plot(gy, which = 1:6)
par(mfrow = c(1, 1))
# }
```

*Documentation reproduced from package betareg, version 3.1-3, License: GPL-2 | GPL-3*