10 REM PROGRAM TO PLOT POLAR FUNCTIONS›20 REM BY HENRIQUE VELUDO FOR ATARI 800›80 DIM A$(1)›90 ? "}"›100 POSITION 7,1:? "GRAPHS OF POLAR FUNCTIONS"›110 POSITION 2,3:? "FUNCTION MENU:":? ›120 ? "     1)R=B*Q             SPIRAL"›130 ? "     2)R=A*(1+COS(Q))    CARDIOID"›140 ? "     3)R=A*(1-SIN(Q))"›150 ? "     4)R=A*SIN(B*Q)      ROSE"›160 ? "     5)R=A*COS(B*Q)"›170 ? "     6)R=COS(A*SIN(B*Q))"›180 ? "     7)R=SIN(A*COS(B*Q))"›190 ? "     8)R=A               POLYGON"›200 ? :? :? "INPUT:":? ›210 ? "FUNCTION #,A,B,INC.,SC.";:INPUT N,A,B,INCR,SC›220 IF N=0 THEN N=1›222 IF N=1 THEN U=4›224 IF A=0 THEN A=1›226 IF B=0 THEN B=1›230 ? :? :? "DO YOU WANT THE X-Y AXES DISPLAYED";›240 INPUT A$:IF A$(1,1)="Y" THEN W=1›300 COLOR 1:GRAPHICS 24›310 I=INT(RND(1)*16)›320 L1=INT(RND(1)*8)*2›330 L2=INT(RND(1)*8)*2›340 IF ABS(LI-L2)<4 THEN 320›350 SETCOLOR 4,I,L1›360 SETCOLOR 2,I,L1›370 SETCOLOR 1,I,L2›380 IF W<>1 THEN 410:REM DISPLAY AXES?›390 FOR I=0 TO 319 STEP 4:PLOT I,96:NEXT I›395 FOR I=0 TO 191 STEP 3:PLOT 160,I:NEXT I›400 REM PLOTTING CALCULATION›410 FOR T=0 TO 360*U STEP INCR›420 Q=T/57.3›430 ON N GOTO 510,520,530,540,550,560,570,580›500 REM EQUATIONS FOR R›510 R=B*Q:GOTO 610›520 R=A*(1+COS(Q)):GOTO 610›530 R=A*(1-SIN(Q)):GOTO 610›540 R=A*SIN(B*Q):GOTO 610›550 R=A*COS(B*Q):GOTO 610›560 R=COS(A*SIN(B*Q)):GOTO 610›570 R=SIN(A*COS(B*Q)):GOTO 610›580 R=A:GOTO 610›600 REM PLOTTING X,Y›610 X=INT((R*COS(Q))*SC)›620 Y=INT((R*SIN(Q))*SC)›630 IF ABS(X)>159 OR ABS(Y)>95 THEN 670›640 IF T=0 THEN PLOT 160+X,96-Y›650 DRAWTO 160+X,96-Y›660 NEXT T›670 FOR I=1 TO 75:POKE 53279,0:NEXT I›675 W=O›680 U=1:OPEN #1,4,0,"K:":GET #1,X:CLOSE #1›690 PUT #6,125:GOTO 90›