*  This is file MUSCLE.SAS  ;
title 'Smooth muscle stretching';
DATA MUSCLE;
     infile muscle;
     input deltaF deltaL F;
     deltaL2=deltaL**2;
     deltaLxF=deltaL*F;
     LABEL deltaF='change in Force'
           deltaL='change in Length'
           deltaL2='squared change in Length'
           deltaLxF='interaction of deltaL and Force';
proc REG  data=muscle;
     model deltaF=deltaL deltaL2 deltaLxF /noint;