DRESIDUALS procedure

Plots residuals (R.W. Payne).

Options

RESIDUALS = variate

Residuals to plot

FITTEDVALUES = variate

Fitted values against which to plot the residuals

INDEX = variate or factor

X-variable for an index plot; default !(1,2...)

GRAPHICS = string

What type of graphics to use (lineprinter, highresolution); default high

TITLE = text

Overall title for the plots; default * i.e. none

Parameters

METHOD = strings

Type of residual plot (fittedvalues, normal, halfnormal, histogram, absresidual, index); default fitt, norm, half, hist

PEN = scalars, variates or factors

Pen(s) to use for each plot

Description

Procedure DRESIDUALS provides up to four types of plots of residuals. These are selected using the METHOD parameter, with settings: fitted for residuals versus fitted values, normal for a Normal plot, halfnormal for a half-Normal plot, histogram for a histogram of residuals, absresidual for a plot of the absolute values of the residuals versus the fitted values, and index for a plot against an "index" variable (specified by the INDEX option). The PEN parameter can specify the graphics pen or pens to use for each plot.

The residuals and fitted values must be supplied, in variates, using the RESIDUALS and FITTEDVALUES options, respectively. The TITLE option can supply an overall title for the plots. By default, high-resolution graphics are used. Line-printer graphics can be requested instead, by setting option GRAPHICS=lineprinter.

Options: RESIDUALS, FITTEDVALUES, INDEX, GRAPHICS, TITLE.

Parameters: METHOD, PEN.

Method

For a Normal plot, the Normal quantiles are calculated as follows:

q_i = NED( (i-0.375) / (n+0.25) )

while for a half-Normal plot they are given by

q_i = NED( 0.5 + 0.5 × (i-0.375) / (n+0.25) )

Action with RESTRICT

If the variates are restricted, only the units not excluded by the restriction will be included in the graphs.