The MODEL statement specifies the dependent variables, the independent regression variables, which are listed with no parentheses, and the independent smoothing variables, which are listed inside parentheses.
The regression variables are optional. At least one smoothing variable is required, and it must be listed after the regression variables. No variables can be listed in both the regression variable list and the smoothing variable list.
If you specify more than one dependent variable, PROC TPSPLINE calculates a thinplate smoothing spline estimate for each dependent variable by using the regression variables and smoothing variables specified on the right side.
If you specify regression variables, PROC TPSPLINE fits a semiparametric model by using the regression variables as the linear part of the model.
Table 103.3 summarizes the options available in the MODEL statement.
Table 103.3: MODEL Statement Options
Option 
Description 

Specifies the significance level 

Specifies the degrees of freedom 

Defines a range in which points are treated as replicates 

Specifies the smoothing parameter 

Specifies a set of values for the parameter 

Specifies the smoothing parameter on the scale 

Specifies a set of values for the parameter on the scale 

Specifies the order of the derivative 

Specifies the range for smoothing values to be evaluated 
You can specify the following options in the MODEL statement: