PIT_ggPlot: ggplot version of PIT Plots for a iZIP Object

In thomas-fung/izipr: Interpretable Zero-Inflated Poisson Models in R

Description

Two plots for the non-randomized PIT are currently available for checking the distributional assumption of the fitted iZIP model: the PIT histogram, and the uniform Q-Q plot for PIT.

Usage

gg_histizipPIT(
  object,
  bins = 10,
  ref_line = TRUE,
  col_line = "red",
  col_hist = "royal blue",
  size = 1
)

gg_qqizipPIT(
  object,
  bins = 10,
  col1 = "red",
  col2 = "#999999",
  lty1 = 1,
  lty2 = 2
)

Arguments

object	an object class "izip", obtained from a call to glm.izip.
bins	numeric; the number of bins shown in the PIT histogram or the PIT Q-Q plot.
ref_line	logical; if TRUE (default), the line for displaying the standard uniform distribution will be shown for the purpose of comparison.
col_line	numeric or character: the colour of the reference line for comparison in PIT histogram.
col_hist	numeric or character; the colour of the histogram for PIT.
size	numeric; the line widths for the comparison line in PIT histogram.
col1	numeric or character; the colour of the sample uniform Q-Q plot in PIT.
col2	numeric or character; the colour of the theoretical uniform Q-Q plot in PIT.
lty1	integer or character string: the line types for the sample uniform Q-Q plot in PIT, see ggplot2::linetype.
lty2	an integer or character string: the line types for the theoretical uniform Q-Q plot in PIT, see ggplot2::linetype.

Details

histizipPIT and qqizipPIT

The histogram and the Q-Q plot are used to compare the fitted profile with a standard uniform distribution. If they match relatively well, it means the iZIP distribution is appropriate for the data.

The histizipPIT and qqizipPIT functions would provide the same two plots but in base R format.

References

Czado, C., Gneiting, T. and Held, L. (2009). Predictive model assessment for count data. Biometrics, 65, 1254–1261.

Dunsmuir, W.T.M. and Scott, D.J. (2015). The glarma Package for Observation-Driven Time Series Regression of Counts. Journal of Statistical Software, 67, 1–36.

See Also

histizipPIT, qqizipPIT, plot.izip and autoplot.izip.

Examples

## For examples see example(autoplot)

thomas-fung/izipr documentation built on Dec. 23, 2021, 9:57 a.m.