ASSESS
VAR=(effect)LINK </ options> ;
ASSESSMENT
VAR=(effect)LINK </ options> ;
The ASSESS statement computes and plots, using ODS Graphics, modelchecking statistics based on aggregates of residuals. See
the section Assessment of Models Based on Aggregates of Residuals for details about the model assessment methods available in GENMOD.
The types of aggregates available are cumulative residuals, moving sums of residuals, and loess smoothed residuals. If you
do not specify which aggregate to use, the assessments are based on cumulative sums. PROC GENMOD uses ODS Graphics for graphical
displays. For specific information about the graphics available in PROC GENMOD, see the section ODS Graphics.
You must specify either LINK or VAR= in order to create an analysis.
LINK requests the assessment of the link function by performing the analysis with respect to the linear predictor.
VAR=(effect) specifies that the functional form of a covariate be checked by performing the analysis with respect to the variable identified
by the effect. The effect must be specified in the MODEL statement and must contain only continuous variables (variables not
listed in a CLASS statement).
You can specify the following options after the slash (/).

CRPANEL

requests that a plot with four panels showing just a few of the paths from the default aggregate plot to make it easier to
compare simulated and observed paths. The plot in each panel contains aggregates of the observed residuals and two simulated
curves (fewer if NPATHS= is less than 8).

LOESS<(number)>
LOWESS<(number)>

requests model assessment based on loess smoothed residuals with optional number the fraction of data used; number must be between zero and one. If number is not specified, the default value onethird is used.

NPATHS=number
NPATH=number
PATHS=number
PATH=number

specifies the number of simulated paths to plot in the default aggregate residuals plot. The default value of number is twenty.

RESAMPLE<=number>
RESAMPLES<=number>

specifies that a pvalue be computed based on 1,000 simulated paths, or number paths, if number is specified.

SEED=number

specifies a seed for the normal random number generator used in creating simulated realizations of aggregates of residuals
for plots and estimating pvalues. Specifying a seed enables you to produce identical graphs and pvalues from one run of the procedure to the next run. If a seed is not specified, or if number is negative or zero, a random number seed is derived from the time of day.

WINDOW<(number)>

requests assessment based on a moving sum window of width number. If number is not specified, a value of onehalf of the range of the xcoordinate is used.