draw a few functions graphics

Hi friends,

I want to ask a question. There are fifty mathematical functions in my programme ( (x^2),(x^3), sinx,cosx.. etc. )Apart from these, there is a button called "+".


When I click "+" button, I will chose some of functions. For example ( sinx, cosx,tanx) The last function will be "sinx+cosx+tanx"

or

I will click "+" button and after that I will click (x^2),(x^3),(x^4). The function will be (x^2)+(x^3)+(x^4)

This is what I want but I can't do this.

How can I do this?

Thanks

I guess you are programming a calculator, to do that, you need to save the state of + button in a module level variable and when you press other function button, check the state of + button and act according it.

Here is a sample

vb Code:

Private mblnPlusPressed As Boolean
Private mdblResult As Double
Private x As Long
 
Private Sub Command1_Click()
    ' this is + button
    mblnPlusPressed = Not mblnPlusPressed
End Sub
 
Private Sub Command2_Click()
    ' this is (x^2) button
    If mblnPlusPressed = True Then
        mdblResult = mdblResult + (x ^ 2)
    Else
        mdblResult = (x ^ 2)
    End If
    ' show mdblResult
    Me.Caption = mdblResult
End Sub
 
Private Sub Command3_Click()
    ' this is (x^3) button
    If mblnPlusPressed = True Then
        mdblResult = mdblResult + (x ^ 3)
    Else
        mdblResult = (x ^ 3)
    End If
    ' show mdblResult
    Me.Caption = mdblResult
End Sub
 
Private Sub Form_Load()
    x = 2
End Sub

Not too sure I understand what you want, but if, for instance you have the Functions in a ListBox you can build up the 'equation' like this

Code:

---

Private strSign As String

Private Sub cmdAdd_Click()
txtEquation.Text = ""
strSign = " + "
End Sub

Private Sub Form_Load()
txtEquation.Text = ""
List.Clear
List.AddItem "Sin(X)"
List.AddItem "Cos(X)"
List.AddItem "Tan(X)"
List.AddItem "(X^2)"
List.AddItem "(X^3)"
List.AddItem "(X^4)"
End Sub

Private Sub List_Click()
Dim intI As Integer
If strSign <> "" And List.ListIndex >= 0 Then
    If txtEquation.Text <> "" Then
        txtEquation.Text = txtEquation.Text & strSign & List.List(List.ListIndex)
    Else
        txtEquation.Text = List.List(List.ListIndex)
    End If
End If
End Sub

---

Just click on cmdAdd then click on each item in the ListBox you want in the 'equation' and you will see the result in txtEquation

There are 8 command buttons
X^2
X^3
x^4
Tan(x)
Sin(x)
Cos(x)
+
Draw


First, I will click "+" button. And after that I will click buttons above which I want ( for example: (x^2),(x^3),(x^4) ) Finally I will click the "Draw" button. The function will be (x^2)+(x^3)+(x^4). It will draw this function's graphic.

This is what I want