Графики и ДУ на VB6

Dim x(), e(), em(), o() As Single
Private i, n As Integer
Private x0, xk, y0, h, miny, maxy, minx, maxx As Single
Function f(a, b) As Single
f = b * (1 / Tan(a))
End Function
Private Sub Eiler()
ReDim x(n + 1)
ReDim e(n + 1)
e(0) = y0
For i = 0 To n
x(i) = Round(x0 + (i * h), 3)
e(i + 1) = Round(e(i) + h * f(x(i), e(i)), 3)
Next i
End Sub
Private Sub RungeKutta()
ReDim x(n + 1)
ReDim em(n + 1)
em(0) = y0
For i = 0 To n
x(i) = Round(x0 + i * h, 3)
k1 = h * f(x(i), em(i))
k2 = h * f(x(i) + (h / 2), em(i) + (k1 / 2))
k3 = h * f(x(i) + (h / 2), em(i) + (k2 / 2))
k4 = h * f(x(i) + h, em(i) + k3)
k = (k1 + 2 * k2 + 2 * k3 + k4) / 6
em(i + 1) = Round(em(i) + k, 3)
Next i
End Sub
Private Sub Obhee()
ReDim x(n + 1)
ReDim o(n + 1)
maxy = y0
miny = y0
maxx = x0
minx = x0
For i = 0 To n
x(i) = Round(x0 + i * h, 3)
o(i) = Round(Sin(x(i)), 3)
Next i
End Sub
Private Sub Command1_Click()
x0 = Val(Text1.Text)
y0 = Val(Text2.Text)
xk = Val(Text3.Text)
h = Val(Text4.Text)
n = Round((xk - x0) / h)
MSFlexGrid1.Cols = 4
MSFlexGrid1.Rows = n + 2
MSFlexGrid1.TextMatrix(0, 0) = "x"
MSFlexGrid1.TextMatrix(0, 1) = "Общее рещение"
MSFlexGrid1.TextMatrix(0, 2) = "эйлер"
MSFlexGrid1.TextMatrix(0, 3) = "Рунге-Кутт"
Eiler
RungeKutta
Obhee
For i = 0 To n
MSFlexGrid1.TextMatrix(i + 1, 0) = Str(x(i))
MSFlexGrid1.TextMatrix(i + 1, 1) = Str(o(i))
MSFlexGrid1.TextMatrix(i + 1, 2) = Str(e(i))
MSFlexGrid1.TextMatrix(i + 1, 3) = Str(em(i))
Next i
minx = x(0)
maxx = x(n)
miny = o(0)
maxy = o(n)
If e(n) > o(n) Then maxy = e(n)
If em(n) > o(n) Then maxy = em(n)
If e(n) > em(n) Then maxy = e(n)
Label10.Caption = Str(miny)
Label11.Caption = Str(maxy)
Label8.Caption = Str(minx)
Label12.Caption = Str(maxx)
Picture1.Cls
kx = (Picture1.Width - 1200) / (xk - x0)
ky = (Picture1.Height - 1000) / (maxy - miny)
For i = 0 To n - 1
z1 = Round(720 + (x(i) - x0) * kx)
z2 = Round(5400 - (e(i) - miny) * ky)
z3 = Round(720 + (x(i + 1) - x0) * kx)
z4 = Round(5400 - (e(i + 1) - miny) * ky)
Picture1.Line (z1, z2)-(z3, z4), RGB(0, 0, 9999)
Next i
For i = 0 To n - 1
z1 = Round(720 + (x(i) - x0) * kx)
z2 = Round(5400 - (em(i) - miny) * ky)
z3 = Round(720 + (x(i + 1) - x0) * kx)
z4 = Round(5400 - (em(i + 1) - miny) * ky)
Picture1.Line (z1, z2)-(z3, z4), RGB(0, 9999, 0)
Next i
For i = 0 To n - 1
z1 = Round(720 + (x(i) - x0) * kx)
z2 = Round(5400 - (o(i) - miny) * ky)
z3 = Round(720 + (x(i + 1) - x0) * kx)
z4 = Round(5400 - (o(i + 1) - miny) * ky)
Picture1.Line (z1, z2)-(z3, z4), RGB(9999, 0, 0)
Next i
End Sub