APLOT procedure

Plots residuals from an ANOVA analysis (R.W. Payne & A.D. Todd).


Options

RMETHOD = string
Type of residuals to plot (simple, standardized); default simp

INDEX = variate or factor
X-variable for an index plot; default !(1,2...)

STRATUM = formula
The stratum (or error term) whose residuals are to be plotted; the default is to plot the residuals from the final stratum

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

TITLE = text
Overall title for the plots; if unset, the identifier of the y-variate is used

SAVE = ANOVA save structure
Specifies the analysis from which the residuals and fitted values are to be taken; by default they are taken from the most recent ANOVA


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 APLOT provides up to four types of plots of residuals from an ANOVA analysis. 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 TITLE option can supply an overall title. If this is not set, the identifier of the y-variate is used.

   The residuals and fitted values are accessed automatically from the structure specified by the SAVE option. If the SAVE option is not set, they are taken from the SAVE structure of the last y-variate to have been analysed by ANOVA. By default, simple residuals are plotted, but you can set option RMETHOD=standardized to plot standardized residuals instead.

   If your design has several strata (or error terms), you can set the STRATUM option to plot the residuals from one of the higher strata. If STRATUM is not set, the residuals from the final stratum are plotted.

   By default, high-resolution graphics are used. Line-printer graphics can be used by setting option GRAPHICS=lineprinter.

 

Options: RMETHOD, INDEX, STRATUM, GRAPHICS, TITLE, SAVE.

Parameters: METHOD, PEN.


Method

Residuals and fitted values are accessed, using AKEEP, from the latest ANOVA, or from that specified by the SAVE option. The plots are produced using the DRESIDUALS procedure.


Action with RESTRICT

If the y-variate in the ANOVA was restricted, only the units not excluded by the restriction will be included in the graphs.