The PROC GENSELECT statement invokes the procedure. Table 7.1 summarizes the available options in the PROC GENSELECT statement by function. They are then described fully in alphabetical order.
Specifies the convergence criterion for the LASSO method
The optimization options are fully described in the section Optimization Options in Chapter 3: Shared Concepts. The following list describes the other options available in the PROC GENSELECT statement:
ALPHA=number
specifies a global significance level for the construction of confidence intervals. The confidence level is 1 – number. The value of number must be between 0 and 1. You can override this global significance level by specifying this option in the OUTPUT statement. By default, ALPHA=0.05.
PAGESIZE=number | AUTO
MAXOPTBATCH=number | AUTO
specifies the maximum number of observations to be included in a batch. During the optimization, the GENSELECT procedure reads at most number observations from the data table into memory, performs the appropriate log-likelihood, gradient, and Hessian computations on that batch of observations, then discards those observations and reads in the next batch of data for processing. Generally, a smaller PAGESIZE value decreases memory usage but might lead to longer computation times, whereas a larger PAGESIZE value might lead to shorter computation times but increases memory usage. The default PAGESIZE=AUTO option determines if the entire data table can be held in a subset of your available memory; if not, then it sets PAGESIZE=256.
CORRB
creates the "Parameter Estimates Correlation Matrix" table. The correlation matrix is computed by normalizing the covariance matrix . That is, if is an element of , then the corresponding element of the correlation matrix is , where .
COVB
creates the "Parameter Estimates Covariance Matrix" table. The covariance matrix is computed as the inverse of the negative of the matrix of second derivatives of the log-likelihood function with respect to the model parameters (the Hessian matrix).
DATA=CAS-libref.data-table
names the input data table for PROC GENSELECT to use. The default is the most recently created data table. CAS-libref.data-table is a two-level name, where
CAS-libref
refers to a collection of information that is defined in the LIBNAME statement and includes the caslib, which includes a path to the data, and a session identifier, which defaults to the active session but which can be explicitly defined in the LIBNAME statement. For more information about CAS-libref, see the section Using CAS Sessions and CAS Engine Librefs.
data-table
specifies the name of the input data table.
ITHIST
generates the "Iteration History" table.
LASSORHO=r
specifies the base regularization parameter for the LASSO model selection method. The regularization parameter for step i is r. By default, LASSORHO=0.8.
LASSOSTEPS=n
specifies the maximum number of steps for LASSO model selection. By default, LASSOSTEPS=20.
LASSOTOL=r
specifies the convergence tolerance for the optimization algorithm that solves for the LASSO parameter estimates at each step of LASSO model selection. By default, LASSOTOL=1E–6.
NOCHECK
disables the checking process that determines whether maximum likelihood estimates of the regression parameters exist. For more information, see the section Existence of Maximum Likelihood Estimates.
NOCLPRINT<=number>
suppresses the display of the "Class Level Information" table if you do not specify number. If you specify number, the values of the classification variables are displayed for only those variables whose number of levels is less than number. Specifying number helps to reduce the size of the "Class Level Information" table if some classification variables have a large number of levels.
NOSTDERR
suppresses computation of the covariance matrix and the standard errors of the regression coefficients. When the model contains many variables (thousands), the inversion of the Hessian matrix to derive the covariance matrix and the standard errors of the regression coefficients can be time-consuming. The CORRB, COVB, and TYPE3 options are not available when the NOSTDERR option is specified. This option also disables the quasi-complete separation check; for more information, see the section Existence of Maximum Likelihood Estimates.
PARTFIT
displays fit statistics in the "Fit Statistics" table that are usually produced when your data are partitioned. This option is not required when you specify a PARTITION statement. The statistic that is added to the table is the average square error (or Brier score).
STB
displays the standardized estimates of the parameters in the "Parameter Estimates" table. The standardized estimate of is given by , where is the total sample standard deviation for the ith explanatory variable and
The sample standard deviations for parameters that are associated with CLASS variables are computed using their codings. The standardized estimates are not computed for the intercept parameters.