C-PS/8 FOCAL, 1971
 1.10 T !!,"CHI SQ PROB",!!;E
 1.20 A "CHI2",X,
DF
,;S BX=X
 2.10 S A=.5*X;S E=2*FITR(DF/2)-DF
 2.15 I (E)2.2,2.27,2.2
 2.20 I (DF-2)2.3,2.3,2.27
 2.27 I (BX-40)2.29,2.3,2.3
 2.29 S YY=FEXP(-A)
 2.30 I (E)2.4;S S=YY;G 2.6
 2.40 S X=-FSQT(X);D 10;I (X)2.45,2.45;S P=(Z+1)/2;G 2.5
 2.45 S P=(1-Z)/2
 2.50 S S=2*P
 2.60 I (DF-2)2.7,2.7,3.1
 2.70 T %6.04,!!!,"P ",S," FOR CHI2 ",BX," WITH",%4,DF," DF",!!!
 2.90 G 1.2
 3.10 S X=.5*(DF-1);I (E)3.2;S Z=1;G 3.3
 3.20 S Z=.5
 3.30 I (BX-40)3.8;I (E)3.4;S E=0;G 3.5
 3.40 S E=.572365
 3.50 S C=FLOG(A)
 3.60 I (X-Z)3.7;S E=E+FLOG(Z);S S=FEXP(C*Z-A-E)+S;S Z=Z+1;G 3.6
 3.70 G 2.7
 3.80 I (E)3.85;S E=1;G 3.87
 3.85 S E=.56419/FSQT(A)
 3.87 S C=0
 3.90 I (X-Z)3.95;S E=E*A/Z;S C=C+E;S Z=Z+1;G 3.9
 3.95 S S=C*YY+S;G 2.7
10.10 I (X)10.11,10.2;D 11;R
10.11 D 11;R
10.20 S Z=0;R
11.10 S Y=FABS(X)/2
11.20 I (Y-3)11.3;S Z=1; R
11.30 I (Y-1)11.4;D 12;R
11.40 S W=Y*Y
11.50 S Z=((.000124819*W-.0010752)*W+.00519877)*W
11.60 S Z=(((Z-.0191983)*W+.0590540)*W-.151969)*W
11.70 S Z=(((Z+.319153)*W-.531923)*W+.797885)*Y*2
11.80 R
12.10 S Y=Y-2
12.20 S Z=((-.00004526*Y+.000152529)*Y-.0000195381)*Y
12.30 S Z=(((Z-.000676905)*Y+.0013906)*Y-.00079462)*Y
12.40 S Z=(((Z-.00203425)*Y+.00654979)*Y-.0105576)*Y
12.50 S Z=(((Z+.0116308)*Y-.00927945)*Y+.00535358)*Y
12.60 S Z=((Z-.00214127)*Y+.00053531)*Y+.999937
12.70 R