The best way that I can learn VB is by practice and just get on with it. I never realized that starting something and ending something is harder than the in between process. Good thing it is object-oriented and somehow close to Java. They are almost alike. But not all.
Sobrang nangapa ako sa codes and shortcuts. It's been a very long time since I did some programming.
VBA Shorcuts
- Alt-F11 - Activate VBE
- F5 - Execute Module
The formulas are assumed to be correct. If I put on another char like $y$ in the formula, there will be an error. I can't seem to fix this. Here are the codes:
Colorit.bas
Something Fun. Coloring the highlighted Red. Just learning on the buttons.
Sub Red()
'
' Red Macro
'
With Selection.Interior
.Pattern = xlSolid
.PatternColorIndex = xlAutomatic
.Color = 192
.TintAndShade = 0
.PatternTintAndShade = 0
End With
End Sub
Sub NoFill()
'
' NoFill Macro
'
'
With Selection.Interior
.Pattern = xlNone
.TintAndShade = 0
.PatternTintAndShade = 0
End With
End Sub
Bisection.bas
This contain some of the functions found in the other methods. i didn't include it anymore in the other methods.
Sub Bisectiontest()
'ASSUME THAT THE FORMULA IS CORRECT
'0nly after 1000 iterations of f(x) = 0
form = Range("D4")
a = Range("E6").Value
b = Range("E7").Value
'checks the inputs
If Inputx(form, 0, a, b) = False Then
MsgBox "Please check your inputs"
Exit Sub
'wrong property of bisection
ElseIf Px(form, a) * Px(form, b) > 0 Then
MsgBox "Please change your interval"
Exit Sub
Else
'applying the method
Call Bisection(form, a, b)
End If
End Sub
Public Function Inputx(form, form2, a, b) As Boolean
'Missing input
If form = "" Or form2 = "" Or a = "" Or b = "" Then
Inputx = False
'wrong input on interval
ElseIf a Like "[A-Z,a-z]" Or b Like "[A-Z,a-z]" Then
Inputx = False
Else
Inputx = True
End If
End Function
Public Function Px(f, x)
'This is to evaluate the x variable only
'replacing x with the value
f1 = Application.WorksheetFunction.Substitute(f, "x", x)
'evaluate the string
Px = Evaluate(f1)
End Function
Private Sub Bisection(form, a, b)
Static counter As Integer
xn = (a + b) / 2
fa = Px(form, a)
fxn = Px(form, xn)
fb = Px(form, b)
'stop with 1000 iteration
counter = counter + 1
If counter = 1000 Then
Range("F9").Value = xn
Exit Sub
Else
'checker for next iteration
'assigning new a or b
If fa = 0 Then
Range("F9").Value = a
ElseIf fxn = 0 Then
Range("F9").Value = xn
ElseIf fb = 0 Then
Range("F9").Value = b
ElseIf fa * fxn < 0 Then
b1 = xn
Call Bisection(form, a, b1)
Else
a1 = xn
Call Bisection(form, a1, b)
End If
End If
End Sub
Newton.bas
Sub Newtontest()
'ASSUME THAT THE FORMULAS inputed are CORRECT
'0nly after 1000 iterations of f(x) = 0
form = Range("E5")
form2 = Range("E6")
a = Range("F8").Value
'checks the inputs
If Inputx(form, form2, a, 0) = False Then
MsgBox "Please check your inputs"
Exit Sub
'property of newton
ElseIf Px(form2, a) = 0 Then
MsgBox "Please change your x. The first derivative is 0."
Exit Sub
Else
'applying the method
Call Newton(form, form2, a)
End If
End Sub
Private Sub Newton(form, form2, a)
Static counter As Integer
f = Px(form, a)
fprime = Px(form2, a)
'stop with 1000 iteration
counter = counter + 1
If Not counter = 1000 Then
'checker for next iteration
'assigning new xn
If f = 0 Then
Range("G10").Value = a
Else
xn = a - (f / fprime)
Call Newton(form, form2, xn)
End If
Else
Range("G10").Value = a
Exit Sub
End If
End Sub
Secant.bas
Sub Secanttest()
'ASSUME THAT THE FORMULAS inputed are CORRECT
'0nly after 1000 iterations of f(x) = 0
form = Range("E5")
x1 = Range("F7").Value
x2 = Range("F8").Value
'checks the inputs
If Inputx(form, 0, x1, x2) = False Then
MsgBox "Please check your inputs"
Exit Sub
'property of secant
ElseIf Px(form, x1) = Px(form, x2) Then
MsgBox "f(x1) = f(x2). Please change your points"
Exit Sub
Else
'applying the method
Call Secant(form, x1, x2)
End If
End Sub
Private Sub Secant(form, x1, x2)
Static counter As Integer
f1 = Px(form, x1)
f2 = Px(form, x2)
'stop with 1000 iteration
counter = counter + 1
If Not counter = 1000 Then
'checker for next iteration
'assigning new xn
If f1 = 0 Then
Range("G10").Value = x1
ElseIf f2 = 0 Then
Range("G10").Value = x2
Else
xn = x2 - f2 * ((x2 - x1) / (f2 - f1))
Call Secant(form, x2, xn)
End If
Else
Range("G10").Value = x2
Exit Sub
End If
End Sub
Fixedpoint.bas
Sub Fixedpointtest()
'ASSUME THAT THE FORMULAS inputed are CORRECT
'0nly after 1000 iterations of f(x) = 0
form = Range("E5")
form2 = Range("E6")
a = Range("F8").Value
'checks the inputs
If Inputx(form, form2, a, 0) = False Then
MsgBox "Please check your inputs"
Exit Sub
Else
'applying the method
Call Fixedpoint(form, form2, a)
End If
End Sub
Private Sub Fixedpoint(form, form2, a)
Static counter As Integer
f = Px(form, a)
g = Px(form2, a)
'stop with 1000 iteration
counter = counter + 1
If Not counter = 1000 Then
'checker for next iteration
'assigning new xn
If f = g Then
Range("G10").Value = a
Else
xn = g
Call Fixedpoint(form, form2, xn)
End If
Else
Range("G10").Value = a
Exit Sub
End If
End Sub
I realized how i missed programming. Its so much different that recording it into a macro. Although that helps but you can't define a function or apply my own kinda style in programming. Maybe a mixture of the two can help me this time.
