dpit-methods: Methods for DPIT residual objects

In assessor: Assessment Tools for Regression Models with Discrete and Semicontinuous Outcomes

Methods for DPIT residual objects

Description

Methods for printing, summarizing, plotting, and extracting values from objects returned by dpit(), dpit_2pm(), and the distribution-specific DPIT calculators. The print method displays the fitted model call or calls, when available, and the sample size. The summary method reports quantiles, mean, and standard deviation for the selected scale. The residuals method extracts the DPIT residuals, and the plot method constructs a QQ plot of the DPIT residuals against its reference distribution.

Usage

## S3 method for class 'dpit'
print(x, ...)

## S3 method for class 'dpit'
residuals(object, scale = c("normal", "uniform"), ...)

## S3 method for class 'dpit'
summary(object, scale = c("normal", "uniform"), ...)

## S3 method for class 'summary.dpit'
print(x, ...)

## S3 method for class 'dpit'
plot(x, scale = c("normal", "uniform"), line_args = list(), ...)

Arguments

x	A dpit object to be printed or plotted by print.dpit() or plot.dpit(), or a summary.dpit object to be printed by print.summary.dpit().
...	Additional arguments passed to or from methods. For plot.dpit(), graphical arguments are passed to stats::qqplot() for customizing the QQ plot (e.g., pch, col, cex, xlab, ylab).
object	A dpit object whose residuals are extracted by residuals.dpit() or summarized by summary.dpit().
scale	You can choose the scale of the residuals among normal and uniform. The sample quantiles of the residuals are plotted against the theoretical quantiles of a standard normal distribution under the normal scale, and against the theoretical quantiles of a uniform (0,1) distribution under the uniform scale. The default scale is normal.
line_args	A named list of graphical parameters passed to graphics::abline() to modify the reference (red) 45° line in the QQ plot. If left empty, a default red dashed line is drawn.

Value

residuals.dpit() returns a numeric vector of DPIT residuals. summary.dpit() returns an object of class summary.dpit. The print and plot methods return their input invisibly.

assessor documentation built on Aug. 22, 2026, 9:06 a.m.