How to put an interactive line on a chart?

[Mas Juliza Alias]

Hi,

I am developing a program that have a 2d line chart of Depth vs Volume. Below the chart there is a textbox where user can enter a depth value. Is it possible to have a line along the depth on the chart? The line should be at 0m depth by default. Plus, if possible, how to highlight the bounded region by the line and volume at that depth with any color different from its background?

Attached is the program i have so far. The depth to be entered by user is the txtRTimeDepth. Your help is highly appreciated.

TQ.

[Guido Geurs]

Please can you attach ALL the files?
I get an error on loading the VBP: some files are missing in the ZIP.

[Mas Juliza Alias]

Here they are. All I need is an interactive line on the chart representing the real time depth as entered by user in the text box at the bottom of the form (frmMainMenu).

Can you take a look at my frmCommPort also? I am stuck at the code to receive data from comm port.

TQ.

[Guido Geurs]

Add a command button (ComDraw) with the code= (this will put the line to the coordinates (0,0) in the chart)

Private Sub ComDraw_Click()
   With ChartFraTESCalc
      FrameGraphRTL.Left = .Left + 970
      FrameGraphRTL.Top = .Top + .Height - 1040
      With .Plot.LocationRect
         FrameGraphRTL.Width = .Max.X - .Min.X - 970
      End With
   End With
End Sub

Still to code:
- When the form resizes: replace the line
- calculate the Y value of the line when a user enters a value in txtRTimeDepth box.

[Guido Geurs]

Attached is the code for the Depth line in the Graph.
I have searched for a definition for a "drop-line" in the chart but nothing found.
So I have used a Fram as line and calculated the coordinates.

[Mas Juliza Alias]

I tried to run your code using the attached data. However, when I enter a value in the real time level box, the message "The Value of Real Time Value is TOO HIGH" appears, even though the value I entered is still in the range.

Can we use the chart (ChartFraTESCalc) to draw the real time level line? For instance, if I enter -3.00 in the Real Time Level box, a new line along the -3.00 will be drawn on the graph. And when we enter another value, the line will be moved to that value line. Is it possible?

TQ...

[Guido Geurs]

Sorry, my mistake.
I was still using the data from "cubic.txt" in which the MAX. value was positive.
In the data from "volumeTrapezium.txt", the MAX. is still negative.
So the code for the error trap of the maximum value should also be:

...
      If txtRTimeDepth > CDbl(ARRAYGRAPH(UBound(ARRAYGRAPH), 2)) Then
...

PS: I have also modified the DIM in "dlgTableTerramodel"

...Public Sub cmdNext_Click()
Dim ARRAYDATAidx As Double...

[Mas Juliza Alias]

That works nicely! Thanks for the notes, they really helps my understanding of your codes.

However is it possible if the line stops at the graph line? My supervisor suggested for a horizontal line from the Y axis to the curve and a vertical line from X axis to the curve, to show the real time depth and volume by using the graph. But I don't have idea how to do this. Thank You in advance.

[Guido Geurs]

Sorry for this late response but there were a lot of problems to solve.
I have found a lot of questions on the web about drawing drop-lines but never an answer.
So I have written my own drop-lines.
I have also added a tool FOR THE DEVELOPER ONLY = "Calibration".
You can activate it with the red button on the graph frame.
You can hide it by setting the line

   frmMainMenu.ComCalibrate.Visible = True

to comment in the FrmSplash.
You can also run the program in his original form (for the user) by comment or delete the other lines:(this is only for the developer to go directly to the chart)

   Call frmMainMenu.mnuDownloadTerramodel_Click
   DoEvents
   With dlgBrowseTerramodel
      .txtFile.Text = App.Path & "\" & "volumeTrapezium.txt"
      Call .cmdNext_Click
   End With
   DoEvents
   Call dlgContentTerramodel.cmdNext_Click
   DoEvents
   Call dlgTableTerramodel.cmdNext_Click
   DoEvents

The tool "calibration" let you see where the boundaries are of the Chart element.
The green buttons are only information.
The red buttons and according scrollbars must be set because these values can't be retrieved from the element Chart.
These values are needed to calculate the coordinates of the drop-lines.
These values are also set by clicking "Apply" and saved when the program is closed with the message "Save the settings ?" in the settings.ini.

[Mas Juliza Alias]

I am sorry but I don't understand how to use the calibration tool. I look through it and also the code but somehow I don't get it. When I import a volume file, the lines do not lie in the place they should be as the value I entered in the text box. I think it has something to do with the calibration, right? Can you explain how to use it?
Also, you have changed the graph axis, Depth and Volume. I prefer Depth in Y-axis and Volume in X-axis. I tried to change it but somehow it effects other calculation though.
Sorry again for my limited VB knowledge. I really appreciate your time on helping me on this. Thank YOU.

[Guido Geurs]

This is with the Depth on the Y axis and a document in .DOC and .PDF explaining the use of the calibration

[Mas Juliza Alias]

THANK YOU! The codes work super nice! Plus your .pdf file helps me A LOT to understand the Calibration tool. I'm totally into it right now. Thanks again! :)

[Mas Juliza Alias]

I have a problem here. My VB6 has no UserCtlCalib component. Where can i get it?
TQ

[Guido Geurs]

This is not a standard control.
This is a control I have created for this application.
You find the file in my attachment as:"ReTISRO_v1.4.0_UserCtlCalib.ctl"
You can load it in your application with "Add" - "Usercontrol" in the Project window. (see last attachment.

PS: you can always create your own controls in vb6!

[Mas Juliza Alias]

Oh I see... I am sorry for my limited knowledge. I have searched and read about it. Thanks!

[Mas Juliza Alias]

There is a problem here when 0 depth is entered. The volume should be 400 but it appears as 0. How can I fix this?
TQ

[Guido Geurs]

Because there is no value above "0" you can't interpolate.
So when depth = 0 the it's the max of volume.
The code for the calculation will be=

Private Function CalcVolume(DEPTH As Double) As Double
Dim ROWidx As Integer
Dim ELEVATIONmin As Double
Dim ELEVATIONmax As Double
Dim VOLUMEmin As Double
Dim VOLUMEmax As Double
Dim VOLUMEDIF As Double
   With GridFraTESCalc
      If CDbl(txtRTimeDepth.Text) = CDbl(ARRAYGRAPH(UBound(ARRAYGRAPH), 2)) Then
         CalcVolume = Format(CDbl(ARRAYGRAPH(UBound(ARRAYGRAPH), 1)), "0.000")
      Else
         For ROWidx = 1 To .Rows - 1
            If CDbl(.TextMatrix(ROWidx, 0)) > DEPTH Then
               ELEVATIONmin = CDbl(.TextMatrix(ROWidx - 1, 0))
               ELEVATIONmax = CDbl(.TextMatrix(ROWidx, 0))
               VOLUMEmin = CDbl(.TextMatrix(ROWidx - 1, 1))
               VOLUMEmax = CDbl(.TextMatrix(ROWidx, 1))
               VOLUMEDIF = (VOLUMEmax - VOLUMEmin) * _
                           (DEPTH - ELEVATIONmin) / _
                           (ELEVATIONmax - ELEVATIONmin)
               CalcVolume = Format(VOLUMEmin + VOLUMEDIF, "0.000")
               Exit Function
            End If
         Next
      End If
   End With
End Function

[Mas Juliza Alias]

Oh I see... So you just add the If function to read the graph data for the first value, am I right? The code works nicely. Thank YOU!

[Mas Juliza Alias]

I am facing a problem here. I am using a data with positive and negative values. When I enter the positive value for the elevation, an error message "Run-Time Error '380', Invalid property values" appears highlighting this line

With FrameGraphRTLx
   .Left = FrameGraphRTLy.Left + FrameGraphRTLy.Width
   .Top = FrameGraphRTLy.Top
   .Height = (Abs(Ymin) - Abs(CDbl(txtElevUser.Text))) * TWIPSy 'highlighted line of the error debug
   .Visible = True
End With
 

When I enter negative value of the elevation, the X line appear at the positive value as in the attached picture. How am I supposed to fix this?

[Mas Juliza Alias]

To use the data files, create new file (File > New) and download the data file (Download/Import). Data file with positive and negative values of elevation is trapezoidal_volume_shift3m.txt file. TQ.

[Guido Geurs]

This is how you can modiffy the calculations for all kind of data: (see also attachment)

'§ draw lines
   With ChartFraTESCalc.Plot.LocationRect
      PLOTmaxX = .Max.X
      PLOTminX = .Min.X
      PLOTmaxY = .Max.Y
      PLOTminY = .Min.Y
   End With
   Xmax = CDbl(ARRAYGRAPH(UBound(ARRAYGRAPH), 1))
   Xmin = CDbl(ARRAYGRAPH(LBound(ARRAYGRAPH), 1))
   Ymax = CDbl(ARRAYGRAPH(UBound(ARRAYGRAPH), 2))
   Ymin = CDbl(ARRAYGRAPH(LBound(ARRAYGRAPH), 2))
   TWIPSx = CDbl(PLOTmaxX - PLOTminX - PLOTGRIDleft - PLOTGRIDright) / Abs(Xmax - Xmin)
   If Ymax > 0 And Ymin < 0 Then
      TWIPSy = CDbl((PLOTmaxY - PLOTminY - PLOTGRIDtop - PLOTGRIDbottom) / Abs(Abs(Ymax) + Abs(Ymin)))
   Else
      TWIPSy = CDbl((PLOTmaxY - PLOTminY - PLOTGRIDtop - PLOTGRIDbottom) / Abs(Abs(Ymax) - Abs(Ymin)))
   End If
   With FrameGraphRTLy
      .Left = ChartFraTESCalc.Left + PLOTminX + PLOTGRIDleft
      If Ymax > 0 And CDbl(txtElevUser.Text) < 0 Then
         .Top = ChartFraTESCalc.Top + (ChartFraTESCalc.Height - PLOTmaxY) + PLOTGRIDtop + _
               (Abs(Abs(Ymax) + Abs(CDbl(txtElevUser.Text))) * TWIPSy)
      Else
         .Top = ChartFraTESCalc.Top + (ChartFraTESCalc.Height - PLOTmaxY) + PLOTGRIDtop + _
               (Abs(Abs(Ymax) - Abs(CDbl(txtElevUser.Text))) * TWIPSy)
      End If
      .Width = (VOLUME - Xmin) * TWIPSx
      .Visible = True
   End With
   With FrameGraphRTLx
      .Left = FrameGraphRTLy.Left + FrameGraphRTLy.Width
      .Top = FrameGraphRTLy.Top
      If CDbl(txtElevUser.Text) > 0 And Ymin < 0 Then
         .Height = (Abs(Abs(CDbl(txtElevUser.Text)) + Abs(Ymin)) * TWIPSy)
      Else
         .Height = (Abs(Abs(CDbl(txtElevUser.Text)) - Abs(Ymin)) * TWIPSy)
      End If
      .Visible = True
   End With

[Guido Geurs]

If the data will be of different types: min-plus, plus-plus, min-min, than the place of the plotgrid will change and the user must adapt the boundaries.
So I have added a simple calibration tool to do it.(see attachment)