Data Smoothing: Loess |
Method Tab |
You can use the Method tab to specify options for the loess algorithm. The Method tab contains the following UI controls:
specifies how to choose the loess smoothing parameter. This list corresponds to the SELECT= option in the MODEL statement.
selects the smoothing parameter that minimizes the corrected Akaike’s information criterion.
selects the smoothing parameter that minimizes the generalized cross validation criterion.
selects the smoothing parameter for which the trace of the prediction matrix is closest to the Target model DF. This value corresponds to the SELECT=DF1 option in the MODEL statement.
enables you to specify the value in the Smoothing parameter field.
specifies that a global minimum be found within the range of smoothing parameter values examined. This check box corresponds to the GLOBAL modifier to the SELECT= option in the MODEL statement. This option is computationally expensive.
specifies that only smoothing parameters greater than or equal to Lower bound and less than or equal to Upper bound be examined.
specifies the number of iterative reweighting steps. SAS/IML Studio counts the initial fit as the th reweighting iteration. This differs from the LOESS procedure, which counts the initial fit as the first iteration. Thus if you type in this field, the option corresponds to ITERATIONS= in the MODEL statement.
specifies whether the interpolating polynomial is linear or cubic. This list corresponds to the INTERP= option in the MODEL statement.
specifies the method to use for calculating the "lookup" degrees of freedom used in performing statistical inference. This list corresponds to the DFMETHOD= option in the MODEL statement.
specifies the degree of the local polynomial to use for each local regression. The choice is linear or quadratic. This list corresponds to the DEGREE= option in the MODEL statement.
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