70MODE2 80VDU19,0,4,0,0,0 90REPEAT 100PROCinput 110PROCinitialise 120PROCplot 130PRINT"press a key "; 140A$=GET$:IF A$="D":*GDUMP 150UNTIL A$="E" 160END 170: 180DEFPROCinitialise 190step=0.02 200IF a>15 OR b>15 THEN step=0.002 210m=0.1E-30 220FOR z=0 TO 2*PI STEP 0.1 230r=ABS(FNequation) 240IF m<r THEN m=r+step 250NEXT 260ENDPROC 270: 280DEFPROCinput 290CLS 300PRINTTAB(20,5)"1..R=1" 310PRINTTAB(20)"2..R=SIN(Z)" 320PRINTTAB(20)"3..R=SIN(5*Z)" 330PRINTTAB(20)"4..R=1+2*COS(Z)" 340PRINTTAB(20)"5..R=1+COS(Z)" 350PRINTTAB(20)"6..R=1+SIN(2*Z)" 360PRINTTAB(20)"7..R=1+2*COS(2*Z)" 370INPUT''"Enter a number (1-7)"n 380IF n<1 OR n>7 THEN GOTO 290 390INPUT"A = "a 400INPUT"B = "b 410ENDPROC 420: 430DEFPROCplot 440CLS 450FOR z=0 TO 2*PI+step STEP step 460r=FNequation 470X%=640+512*COS(a*z)*r/m 480Y%=512+512*SIN(b*z)*r/m 490IF z=0 THEN MOVE X%,Y% 495GCOL0,RND(7) 500DRAW X%,Y% 510NEXT z 520ENDPROC 530: 540DEFFNequation 550IF n=1 =1 560IF n=2 =SIN(z) 570IF n=3 =SIN(5*z) 580IF n=4 =2*COS(z) 590IF n=5 =1+COS(z) 600IF n=6 =1+SIN(2*z) 610=1+2*COS(2*z)