Steema Central

Posted: **Tue Oct 12, 2010 12:48 pm**

Hi,

How can I implement a function to find optimal min max axis after zooming ?
I use SetMinMax function but it does not work, the max value of my serie (for current zoom range) is not on the top of the max axis

Code: Select all

 
Private Sub AxTChart_OnZoom(ByVal sender As Object, ByVal e As System.EventArgs) Handles AxTChart.OnZoom
Dim Min As Double
Dim Max As Double

Min = AxTChart.Series(0).MinVisibleValue(1)
Max = AxTChart.Series(0).MaxVisibleValue(1)
AxTChart.Axis.Left.SetMinMax(Min, Max)
End Sub

: zoom00.jpg (101.52 KiB) Viewed 11268 times

: zoom01.jpg (77.79 KiB) Viewed 11264 times

Thanks for your help (I did not found any topic about this

)

Guilz

Posted: **Wed Oct 13, 2010 8:55 am**

Hi Guilz,

You could do something as the local minimum and maximum example suggested here. You could use series' FirstVisibleIndex and LastVisibleIndex as first and last arguments. This is a TeeChart .NET thread but same should apply to ActiveX version.

Hope this helps.

Posted: **Wed Oct 13, 2010 9:21 am**

Hi Guilz,

Alternatively, you could try forcing a chart repaint before using the MinVisibleValue and MaxVisibleValue functions. Something like:

Code: Select all

AxTChart.Environment.InternalRepaint

Posted: **Wed Oct 13, 2010 9:45 am**

Hi Yeray,

Code: Select all

AxTChart.Environment.InternalRepaint

is working fine with 1 serie but...
let's consider my new example:

: zoom02.jpg (225 KiB) Viewed 11261 times

Code: Select all

    Private Sub AxTChart_OnZoom(ByVal sender As Object, ByVal e As System.EventArgs) Handles AxTChart.OnZoom
        Dim Min As Double = 99999999
        Dim Max As Double = -99999999

        AxTChart.Environment.InternalRepaint()
        For i = 0 To AxTChart.SeriesCount - 1
            If AxTChart.Series(i).MinVisibleValue(1) < Min Then
                Min = AxTChart.Series(i).MinVisibleValue(1)
            End If
            If AxTChart.Series(i).MaxVisibleValue(1) > Max Then
                Max = AxTChart.Series(i).MaxVisibleValue(1)
            End If

        Next

        AxTChart.Axis.Left.SetMinMax(Min, Max)
    End Sub

And the result is not correct as bellow...

: zoom03.jpg (202.96 KiB) Viewed 11258 times

How can take in account the left and right axis ?

Thanks for your help...

Guilz

Posted: **Wed Oct 13, 2010 12:48 pm**

Hi Guliz,

In that case I'm afraid you should control the full zoom manually as in the example Narcis suggested.
If you find problems with it, don't hesitate to let us know.

Posted: **Wed Oct 13, 2010 1:11 pm**

Yeray,

I'm afraid Zoomed Event does not exist in Teechart v8....

Could you give us a sample code in VB to do that because the topic is confusing...
(A simple example with 2 differents axis (left and right) and 1 serie associated to right axis and another one to left axis) with the method to fit exactly the 2 series to the zoomed area will be very usefull !

Thanks a lot for us

Guilz

Posted: **Thu Oct 14, 2010 8:34 am**

Hi Guilz,

Finally, it wasn't so trivial...
I've made the example with Point series because it's easier (with Line series you may also want to consider the line segments, not only the points in the area selected)

Code: Select all

Dim MouseDownX, MouseDownY, MouseUpX, MouseUpY As Integer

Private Sub Form_Load()
  TeeCommander1.ChartLink = TChart1.ChartLink
   
  TChart1.Legend.Visible = False
  TChart1.Aspect.View3D = False
  
  Dim i As Integer
  For i = 0 To 1
    TChart1.AddSeries scPoint
    TChart1.Series(i).FillSampleValues 100
    TChart1.Series(i).asPoint.Pointer.VerticalSize = 2
    TChart1.Series(i).asPoint.Pointer.HorizontalSize = 2
    
    If i Mod 2 = 0 Then
      TChart1.Series(i).VerticalAxis = aRightAxis
    End If
  Next i

  TChart1.Axis.Left.GridPen.Visible = False
End Sub

Private Sub TChart1_OnMouseDown(ByVal Button As TeeChart.EMouseButton, ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
  MouseDownX = X
  MouseDownY = Y
End Sub

Private Sub TChart1_OnMouseUp(ByVal Button As TeeChart.EMouseButton, ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
  MouseUpX = X
  MouseUpY = Y
End Sub

Private Sub TChart1_OnZoom()
  With TChart1.Axis.Left
    .SetMinMax .CalcPosPoint(MouseUpY), .CalcPosPoint(MouseDownY)
  End With
  With TChart1.Axis.Right
    .SetMinMax .CalcPosPoint(MouseUpY), .CalcPosPoint(MouseDownY)
  End With

  TChart1.Environment.InternalRepaint

  Dim TopPos, BottomPos, tmp, offset As Integer
  offset = 2
  TopPos = -1
  BottomPos = -1
  Dim i, j As Integer
  For i = 0 To TChart1.SeriesCount - 1
    For j = TChart1.Series(i).FirstValueIndex To TChart1.Series(i).LastValueIndex - 1
      tmp = -1
      If TChart1.Series(i).VerticalAxis = aLeftAxis Then
        If TChart1.Series(i).YValues.Value(j) <= TChart1.Axis.Left.Maximum And TChart1.Series(i).YValues.Value(j) >= TChart1.Axis.Left.Minimum Then
          tmp = TChart1.Axis.Left.CalcYPosValue(TChart1.Series(i).YValues.Value(j))
        End If
      ElseIf TChart1.Series(i).VerticalAxis = aRightAxis Then
        If TChart1.Series(i).YValues.Value(j) <= TChart1.Axis.Right.Maximum And TChart1.Series(i).YValues.Value(j) >= TChart1.Axis.Right.Minimum Then
          tmp = TChart1.Axis.Right.CalcYPosValue(TChart1.Series(i).YValues.Value(j))
        End If
      End If
      
      If tmp <> -1 Then
        If TopPos = -1 Or tmp < TopPos Then
          TopPos = tmp
        End If
        If BottomPos = -1 Or tmp > BottomPos Then
          BottomPos = tmp
        End If
      End If
    Next j
  Next i

  If BottomPos <> -1 And TopPos <> -1 Then
    TChart1.Axis.Left.SetMinMax TChart1.Axis.Left.CalcPosPoint(BottomPos + offset), TChart1.Axis.Left.CalcPosPoint(TopPos - offset)
    TChart1.Axis.Right.SetMinMax TChart1.Axis.Right.CalcPosPoint(BottomPos + offset), TChart1.Axis.Right.CalcPosPoint(TopPos - offset)
  End If
End Sub

Posted: **Thu Oct 14, 2010 9:16 am**

Hi Yeray,

Thanks a lot for your reply - it is working like a charm

In my case, I have added the code bellow at the begining of TChart1_OnZoom procedure

Code: Select all

  If TChart1.Zoom.Direction = tzdHorizontal Then
        MouseDownY = TChart1.Axis.Left.IStartPos
        MouseUpY = TChart1.Axis.Left.IEndPos
  End If

to ensure it will be working even if user change the zoom direction property (both->tzdHorizontal)

Regards,

Guilz

Posted: **Thu Oct 14, 2010 10:40 am**

Hi Guilz,

I'm glad to hear that!

Steema Central

Finding optimal Min Max Axis after zooming

Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming

Re: Finding optimal Min Max Axis after zooming