100 'progr. 13 GRAFIEK VAN  R=K*COS(4*SIN(2*PHI))
110 CLEAR ,19202 : SCREEN 105,,3,3
120 DEF FNX(X)=INT(1.55*(50+X)+.5)
130 CLS: KEY OFF
140 U=160: V=160: H=.5: RD=4*ATN(1)/180
150 FOR K=20 TO 160 STEP 10
160 	P=0: GOSUB 1000
170 	X1=INT(U+K*R*COS(P)+H)
180 	Y1=INT(V-K*R*SIN(P)+H)
190 	FOR W=2 TO 360 STEP 2
200 		P=W*RD: GOSUB 1000
210 		X2=INT(U+K*R*COS(P)+H)
220 		Y2=INT(V-K*R*SIN(P)+H)
230 		LINE (FNX(X1),Y1)-(FNX(X2),Y2),1
240 		X1=X2: Y1=Y2
250 	NEXT W
260 NEXT K
270 A$=INKEY$: IF A$="" THEN 270
280 CLS: KEY ON: END
1000 R=COS(4*SIN(2*P))
1010 RETURN

Private Function PoolVorm(ByVal P As Single) As Single
	Dim R As Single = Math.Cos(4 * Math.Sin(2 * P))
	Return R
End Function

'Plaats onderstaande codeblok in de Paint event.

Dim U As Single = 160, V As Single = 160, H As Single = 0.5
Dim RD As Single = 4 * Math.Atan(1) / 180
For K As Integer = 20 To 160 Step 10
	Dim P As Single = 0, R As Single = PoolVorm(P)
	Dim X1 As Single = Int(U + K * R * Math.Cos(P) + H)
	Dim Y1 As Single = Int(V - K * R * Math.Sin(P) + H)
	For W As Integer = 2 To 360 Step 2
		P = W * RD : R = PoolVorm(P)
		Dim X2 As Single = Int(U + K * R * Math.Cos(P) + H)
		Dim Y2 As Single = Int(V - K * R * Math.Sin(P) + H)
		e.Graphics.DrawLine(Pens.Black, X1, Y1, X2, Y2)
		X1 = X2 : Y1 = Y2
	Next
Next

