Составить программу построения известных математических кривых - VB

Dim ind%
Const Pi = 3.14
Private Sub Command1_Click()
ind = ind + 1
If ind > 7 Then ind = 0
 
x0 = Me.Width / 2: y0 = Me.Height / 2
 a = 2: l = 4: p = 2
Cls
For fi = 0.01 To 2 * Pi Step 0.01
Select Case ind
Case 1: r = 100 * a * fi
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Case 2: r = 200 * a / fi
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Case 3: r = 50 * (a * fi ^ 2 - l)
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Me.PSet (x0 + r * Cos(-fi), y0 + r * Sin(-fi))
Case 4:
r = 200 * a * Sqr(fi)
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Me.PSet (x0 - r * Cos(fi), y0 - r * Sin(fi))
Case 5:
r = 100 * (a * Sqr(fi) + l)
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Me.PSet (x0 - r * Cos(fi), y0 - r * Sin(fi))
Case 6:
r = 50 * fi ^ p
Me.PSet (x0 + r * Cos(fi), y0 + r * Sin(fi))
Me.PSet (x0 + r * Cos(-fi), y0 + r * Sin(-fi))
End Select
Next fi
End Sub