data;
infile 'z:\stat706\contrast.dat';
input percent strength;
proc glm;
class percent;
model strength=percent;
contrast 'linear and quadratic' percent -2 -1 0 1 2,
                                percent 2 -1 -2 -1 2;
contrast 'linear and quadratic lof' percent -1 2 0 -2 1,
                                    percent 1 -4 6 -4 1;
run;