[RESOLVED] Beginning: Array of Object (looking for critique)

[webbiz]

Another idea. For each series of prices you have an internal document where you divide each time you add a Ma. So your document may have enabled and not enabled ma. You may divide any ma to two or three, and the reason to do that is to control overlapping, so with splitting you don't give a chance to make anyone an overlapping ma. Why is not good to have overlapping Ma? Because you can't see two of them but one except you have flashing drawings that rotate so at any time one ma is drawing only....

I understand that duplicate MA's are unwanted as you won't be able to see them separately anyway. What I do not understand is this "internal document" that you 'divide'.

Couldn't I just check the ListView items first to make sure one does not already exist before even creating the MA?

:-)

[webbiz]

Here's the modified ADD MA button code that includes checking for possible duplicate.

Private Sub btnAddMA_Click()
Dim bExists As Boolean
Dim lColor As Long
Dim Key As String
Dim Period As Integer

    Period = CInt(txtPeriod.Text)
    lColor = ColorPick1.ColorCode
    Key = "ma" & Format$(Period, "000") & CStr(chkExp.Value)
    
    'Check list to make sure another MA does not match this one exactly
    bExists = CheckMAList(List1, MAs)
    
    If Not bExists Then 'Add new MA
                   
        Set MA = MAs.AddNewMA(Key, Period, chkExp.Value, lColor, chkWidth.Value, 1, True)
        
    Else
        MsgBox "MA already exists!", vbOKOnly
    End If

    FillMAsInto List1, MAs


End Sub

I've replaced the List with ListView control so that I can have color and bold effects.

Private Sub FillMAsInto(Lst As ListView, MAs As cMAs)
Dim sStr As String
Dim sTF As String 'TimeFrame spelled out
Dim sExp As String

    If MAs.Count < 1 Then: Exit Sub
    
    
    Lst.ListItems.Clear
    
    For Each MA In MAs
      
        sExp = " "
        If MA.Exponential = True Then: sExp = " Exponential "
        If MA.TimeFrame = 1 Then: sTF = " Day"
        sStr = MA.Period & sTF & sExp
      
        With Lst.ListItems.Add(, MA.Key, sStr & "Moving Average")
            .Bold = MA.Bold
            .ForeColor = MA.Color
        End With
        
    Next
    
End Sub

Changed the Properties for Width (Int) to Bold (Bool).

Public Key As String
Public Visible As Boolean  'visibility of the Line in a given Chart
Public TimeFrame As Integer  'time frame of chart
Public Exponential As Boolean  'exponential or simple MA?
Public Color As Long 'color of MA line
Public Period As Integer 'averaging period
Public Bold As Boolean 'thin or bold line

I've attached the code of what has been done 'so far' for anyone interested.

[georgekar]

Imagine that all your data are one Ma.You have also a property to make it visible or not. Now think two process, one to divide a Ma to two or three parts. Also you can change the visible property...for two parts you have option for upper or lower Ma, for three you have an option for middle only. With these as rules you can prepare any combination. The same happen when you press enter in a document, you divide a paragraph to two paragraphs, but think if you have to place a paragraph in a paragraph you have to place in three possible positions, top, middle, bottom.

[webbiz]

Imagine that all your data are one Ma.You have also a property to make it visible or not. Now think two process, one to divide a Ma to two or three parts. Also you can change the visible property...for two parts you have option for upper or lower Ma, for three you have an option for middle only. With these as rules you can prepare any combination. The same happen when you press enter in a document, you divide a paragraph to two paragraphs, but think if you have to place a paragraph in a paragraph you have to place in three possible positions, top, middle, bottom.

Thank you georgekar for your comments.

I understand what you are suggesting, being able to turn off or on 'parts' of the MA.

However, for this project that particular method would not be needed.

The app will do two things with the MA data:

1) Display the MA for the FIRST (gFirstBarRecNum) to the LAST (gLastBarRecNum) bar on the price chart (since drawing outside the viewing area is a waste).

2) Allowing hiding the MA (there is a ToolHide function within the app that hides all drawn tools).

[webbiz]

In module1 (module1.bas), here is the code that allows for populating the MA object arrays. CalculateMA in reality is more elaborate that what you see below. I did this to simulate that the data was calculated by CalculateMA.

Option Explicit

Public MAs As New cMAs, MA As cMA

Public sngPrices() As Single
Public gLastRecNum As Long

Public Sub PopulateMA(MAs As cMAs, Optional ByVal Key As String)
Dim x As Integer
Dim arrMAresults() As Single

    ReDim arrMAresults(gLastRecNum)
    
    If Key = "" Then
    
        'Calculate the MA in MAs and populate the array
        For Each MA In MAs
            If Not MA.arrFilled Then 'Make sure array not filled
                
                arrMAresults = CalculateMA(MA.Period, MA.Exponential)
                
                For x = 1 To UBound(sngPrices)
                    MA.arrMA(x) = arrMAresults(x - 1) 'This will be replaced by actual calculated data
                Next x
                
            End If
        Next
    
    Else 'Just fill the MA object indicated by the Key
        
        For Each MA In MAs
            If MA.Key = Key Then
                
                arrMAresults = CalculateMA(MA.Period, MA.Exponential)
                
                For x = 1 To UBound(sngPrices)
                    MA.arrMA(x) = arrMAresults(x - 1)
                Next x
                
            End If
        Next
    
    End If


End Sub

Public Function CalculateMA(ByVal Period As Integer, ByVal IsExponential As Boolean) As Single()

    CalculateMA = sngPrices 'simulating the results of calculation

End Function

I'm not sure the code that references by KEY is the correct way to go about this. Can the object be referenced directly based on Key without having to loop through every MA within the object?

[georgekar]

Not exactly a suggestion for on/off a MA but a way to handle and validate the user input. There are a front where a user see some graphics and there is a layer under that the programmer (you) process a "database" or "array", to create parts, to delete parts and to render. So I wrote the previous post for the manage of MA not exactly for the rendering, the display of MA.
Using a listbox for three or four MA maybe is easy to find anyone a specific one, but for more maybe is better to choose by clicking the drawing. So what I have to offer is a way to use a cursor. So when user click anywhere in the graphic then you get the click and translate to a real position in a like a document structure. Maybe you find a non used block, so click do nothing, or you find a block...and so maybe you change color to make it as cursor like. Then with ctrl and mouse maybe user can expand or reduce the span of MA, and with a shift and mouse move maybe user can shift MA...

[webbiz]

Not exactly a suggestion for on/off a MA but a way to handle and validate the user input. There are a front where a user see some graphics and there is a layer under that the programmer (you) process a "database" or "array", to create parts, to delete parts and to render. So I wrote the previous post for the manage of MA not exactly for the rendering, the display of MA.
Using a listbox for three or four MA maybe is easy to find anyone a specific one, but for more maybe is better to choose by clicking the drawing. So what I have to offer is a way to use a cursor. So when user click anywhere in the graphic then you get the click and translate to a real position in a like a document structure. Maybe you find a non used block, so click do nothing, or you find a block...and so maybe you change color to make it as cursor like. Then with ctrl and mouse maybe user can expand or reduce the span of MA, and with a shift and mouse move maybe user can shift MA...

I appreciate the ideas flowing!

So you are talking about 'manipulation' of the MA drawn on the chart by clicking on the chart.

Perhaps if MAs were the only thing on the chart I could do those things to give it more flexible manipulation. However, many tools can be on the chart at one time and currently the mouse click is being used to either scroll the chart (double-click and hold/move), or to delete tools off the chart (right-click), etc.

For those like myself that use MAs on a chart, it feels more natural to control the MAs by means of a 'setup' window.

But it is an interesting idea.

Thank you. :-)

[webbiz]

And here is the MA drawing routine.

Public Sub DrawMA(MAs As cMAs)
Dim sngVertRange As Single
Dim sngVertIncr As Single
Dim x As Long

    frmChart.pctChart.Scale (1, MAs.Item(1).MaxVal)-(150, MAs.Item(1).MinVal)
    
    For Each MA In MAs
                
             For x = MA.Period + 1 To gLastRecNum - 1
                frmChart.pctChart.Line (x, MA.arrMA(x))-(x + 1, MA.arrMA(x + 1)), MA.Color
             Next x
                
        
    Next
    
End Sub

[webbiz]

Well I think I have the code that I need for my main app. Didn't see any critiques for the code I did post (aside from feature suggestions), so I have to assume the way I wrote this code is appropriate.

The code is attached for anyone who wishes to check it.

Thanks.

ObjectMA.zip

[georgekar]

Use with ... end with for Ma. And it is obvious that you use pixels.That means that the handling of rounding is yours.
With Ma
For X=.Period ....
End With

With first look you have a fault. What are the Bounds of arrMA()...because for each MA you place gLastRecNum-1. You use for next from a specific value in any MA to a global limit. It is totally wrong aproach

[Schmidt]

I would use the existing Let-Property by which you fill the internal array,
to not only assign the new incoming Value to the Array-slot, but at this
occassion I'd also "drag-along" two internal m_Min, m_Max Variables ...

The needed If-Checks would be cheap at this occasion - this way you
won't have to perform an extra-loop as you do currenly in your Min/Max
Properties (instead just hand m_Min and m_Max out, they are always correct,
since any new incoming value was "validated" against them already).

Olaf

[webbiz]

Use with ... end with for Ma. And it is obvious that you use pixels.That means that the handling of rounding is yours.
With Ma
For X=.Period ....
End With

With first look you have a fault. What are the Bounds of arrMA()...because for each MA you place gLastRecNum-1. You use for next from a specific value in any MA to a global limit. It is totally wrong aproach

Thanks for the critique. I will go through the code and add those With...End statements.

The Bounds of arrMA() is ALWAYS gLastRecNum, because that is how it is dimensioned in the class. In my main app, where this code is to go eventually, gLastRecNum is the LAST RECORD available for the chart. The MA array is to match this index value in UBOUND. There are NO MAs that will go beyond this boundary nor fall short of it.

[webbiz]

I would use the existing Let-Property by which you fill the internal array,
to not only assign the new incoming Value to the Array-slot, but at this
occassion I'd also "drag-along" two internal m_Min, m_Max Variables ...

The needed If-Checks would be cheap at this occasion - this way you
won't have to perform an extra-loop as you do currenly in your Min/Max
Properties (instead just hand m_Min and m_Max out, they are always correct,
since any new incoming value was "validated" against them already).

Olaf

So what you are suggesting is to put the Min/Max updating code inside the Let arrMA() method?

Private Sub Class_Initialize()
    m_arrMAmaxentries = gLastRecNum
    m_minVal = 99999
    ReDim m_arrMA(m_arrMAmaxentries) 'Initialize array to global value
End Sub

Option Explicit

Public Key As String
Public Visible As Boolean  'visibility of the Line in a given Chart
Public TimeFrame As Integer  'time frame of chart
Public Exponential As Boolean  'exponential or simple MA?
Public Color As Long 'color of MA line
Public Period As Integer 'averaging period
Public Bold As Boolean 'thin or bold line

Private m_arrMA() As Single  'holds the moving averages
Private m_arrMAmaxentries As Long
Private m_maxVal As Single
Private m_minVal As Single

Friend Property Let arrMA(ByVal Index As Long, ByVal MA_value As Single)
  If Index < 0 Or Index > m_arrMAmaxentries Then Err.Raise 9
  m_arrMA(Index) = MA_value
  
  'Update min/max if necessary
  If MA_value > 0 Then
    If MA_value > m_maxVal Then: m_maxVal = MA_value
    If MA_value < m_minVal Then: m_minVal = MA_value
  End If
  
End Property

Public Property Get MinVal() As Single
    MinVal = m_minVal
End Property

Public Property Get MaxVal() As Single
    MaxVal = m_maxVal
End Property

Something like this?

Thanks.

[webbiz]

dupl

[webbiz]

Use with ... end with for Ma. And it is obvious that you use pixels.That means that the handling of rounding is yours.
With Ma
For X=.Period ....
End With

So georgekar, is this what you are suggesting?

Public Sub DrawMA(MAs As cMAs)
Dim sngVertRange As Single
Dim sngVertIncr As Single
Dim x As Long

    With MAs
        frmChart.pctChart.Scale (1, .Item(1).MaxVal)-(150, .Item(1).MinVal)
    End With
    
    For Each MA In MAs
        With MA
             For x = .Period + 1 To gLastRecNum - 1
                frmChart.pctChart.Line (x, .arrMA(x))-(x + 1, .arrMA(x + 1)), .Color
             Next x
        End With
    Next
    
End Sub

[Schmidt]

[suggestion, to move Min-Max Value-Dragging directly into the Array-Item Let-Prop]

...
Something like this?

Yes - exactly - doesn't really add many extra-cpu-cycles in the new place where
you now moved it to - and on the other hands saves quite a bunch of cycles
by avoiding a complete looping in your former Min/Max-Properties.

I think that example shows, that whilst working through (Friend)-Properties
to fill the Member-Slots of an internal Array (where you lose a bit of performance
compared to direct Array-Member-assignments), there's also a few occasions
where this somewhat slower design offers a few chances to get some of those
"wasted Cycles" back...

What you did with the Min- Max-stuff (during Slot-Assignments of the current
incoming NewValue), you could expand to calculate even other Class-internal stuff
which depends on "looking at every single, ever assigned new Value-Member".

Olaf

[webbiz]

[suggestion, to move Min-Max Value-Dragging directly into the Array-Item Let-Prop]



Yes - exactly - doesn't really add many extra-cpu-cycles in the new place where
you now moved it to - and on the other hands saves quite a bunch of cycles
by avoiding a complete looping in your former Min/Max-Properties.

I think that example shows, that whilst working through (Friend)-Properties
to fill the Member-Slots of an internal Array (where you lose a bit of performance
compared to direct Array-Member-assignments), there's also a few occasions
where this somewhat slower design offers a few chances to get some of those
"wasted Cycles" back...

What you did with the Min- Max-stuff (during Slot-Assignments of the current
incoming NewValue), you could expand to calculate even other Class-internal stuff
which depends on "looking at every single, ever assigned new Value-Member".

Olaf

Cool. I must be catching on. Thanks. :-)

I can't think of anything else at the moment that I need to do to these 'single' values internally. From here they go straight to being plotted on the chart.

I've learned a bunch. Mucho Gracias guys!