SAS Adaptivereg Limiting Breakpoints -

i using sas's adaptivereg procedure create piece-wise linear function temperature (temp) x variable , usage (usage_value) y variable. can use details of adaptivereg procedure find ranges of different linear functions of piece-wise function. there way can limit number of ranges, (i.e. instead of having 8 linear functions in piece-wise function, want limit 5 linear functions). there options can add let me limit amount of linear functions?

below code using. a1 name of data set, temp independent variable, , usage_value dependent variable.

proc adaptivereg data=a1 plots=all details=bases;     model usage_value = temp; run; 

i love adaptivereg. it's such cool little procedure.

you can use df option in model statement control total number of knots consider, , maxbasis option control maximum number of knots in final model. higher degrees of freedom use, fewer knots.

proc adaptivereg data=sashelp.air;     model air = date / df=12 maxbasis=3; run; 

you can use alpha= option fine-tune it. increasing alpha result in more knots.

an alternative approach can using pbspline/spline options in transreg or proc quantreg, respectively.

proc transreg data=sashelp.air;     model identity(air) = pbspline(date / evenly=6); run;  proc quantreg data=sashelp.air;     effect sp = spline(date / knotmethod=equal(12) );     model air = sp / quantile=0.5; run;