C-PS/8 FOCAL, 1971
 1.01 C     POLAR BY STEVE POULSEN
 1.02 C     OMSI SOFTWARE DEVELOPMENT GROUP
 1.03 C     LAST CHANGE: 8/19/71
 1.04 C     ***** TEKTRONIX T-4002 GRAPHICS TERMINAL REQUIRED *****
 1.05 
 1.06 C     THIS PROGRAM WILL GRAPH ANY TWO-DIMENSIONAL EQUATION ON A POLAR
 1.07 C COORDINATE SYSTEM.  TYPE ANYTHING BUT YES IF YOU WANT TO INPUT AN 
 1.08 C EQUATION WHEN ASKED IF THE EQUATION IS IN, AND THE COMPUTER WILL INTERRUPT
 1.09 C THE PROGRAM AND ALLOW YOU TO MODIFY ITS INPUT EQUATION.  TYPE AN 	=	
 1.10 C AND YOU WILL GET THE FIRST PART OF THE EQUATION SINCE IT IS IN
 1.11 C MODIFY MODE.  IF YOU CHOOSE NOT TO MODIFY THE EQUATION, THE PROGRAM WILL
 1.12 C ASSUME R=T.  REMEMBER, THE EQUATION MUST BE R (RADIUS) IN TERMS OF
 1.13 C T (THETA).
 1.14 C ** INITIAL ANGLE IS THE POSITION FROM WHICH R WILL BE ROTATED. (DEGREES)
 1.15 C ** FINAL ANGLE IS THE POSITION THROUGH WHICH R WILL BE ROTATED. (DEGREES)
 1.16 C ** ANGLE INCREMENT IS THE STEP WITH WHICH R WILL BE ROTATED. (DEGREES)
 1.17 C ** RADIUS OF AXES IS THE SCALING FEATURE WHICH SETS THE LENGTH OF
 1.18 C    THE X AND Y AXES.
 1.19 
 1.20 U ((/3)-FITR(/3)) 1.21,1.21
 1.21 T "YOU DO NOT HAVE ENOUGH FEATURES.  RESTART FOCAL WITH FEATURE 2.";Q
 1.22 
 1.29 D 12;A "HAVE YOU ENTERED THE EQUATION
",AN
 1.30 I (AN-0YES) 1.4,2.1,1.4
 1.40 T !"ENTER EQUATION OF R IN TERMS OF THE ANGLE T"!!;M 10.1
 2.10 A !"INITIAL ANGLE
",A1,!"FINAL ANGLE
",A2,!"ANGLE INCREMENT
",A3
 2.20 A !"RADIUS OF AXES
",R1;S C=3.1415926/180;S S=380/R1
 2.30 S A1=A1*C;S A2=A2*C;S A3=A3*C;D 12
 3.10 S Q=FDIS(0,132,380)+FDIS(1,892,380)+FDIS(0,512,10)+FDIS(1,512,750)
 3.20 S Q7=FOUT(1)
 4.10 F T=A1,A3,A2;D 10;D 5
 4.20 S Q=FOUT(1);A !"AGAIN
",AG;I (AG-0YES) 20.1,1.2,20.1
 5.10 S X=512+R*S*FCOS(T);S Y=380+R*S*FSIN(T);I (FABS(R*S)-380)5.2;S I=0
 5.20 S Q=FDIS(I,X,Y);I (FABS(R*S)-380)5.3;R
 5.30 S I=1;R
10.10 S R=T
12.10 F Q7=1,.2,FOUT(24);
12.20 S Q7=FOUT(1);R
20.10 Q