Trendline with Snap to Point & Semi log Aware Trendline

[Quant]

Here we have 2 requirements:
1] Draw Line with Snap to Point
This requires drawing a Line with "Snap to Point" option similar as Cursor Tool's Snap Feature.

2] Semi Log Aware Line [Dependent on requirement 1]
Say e.g. we have a normal Candle Series and we draw the line which is based on this candle series. Now assume that we changed this Candle to Logarithmic with log base equal to 10. Since the previously drawn line is based on Candle Series this line should now updated as per the Logarithmic Candle Series. In this transformation the line may change its appearance from straight line to curved line. Same can happen vice versa.

Please help us in solving above two requirements.

[Christopher]

Hello Quant,

Would you be so kind as to send us some example code you have already written to implement these requirements of yours?

It would save us a lot of time to work on what you have already done rather than writing an application for you from scratch. If you could also send us some screenshots of what functionality you would like to see in your code but haven't been able to implement, that would also be greatly appreciated.

[Quant]

We yet to start work on this, but we can explain you both the requirement in more detail.

1] Draw Line with Snap to Point (Check below Image 1):
As shown in the screenshot we draw two trend lines. The Pink Line is normal line without Snap to Point Option. Whereas the Green Line as you see are attached to series points. Green line is drawn using Snap to Point Option. Both Start and End points of Green Line are attached to CandleStick Series.

Image (1): Snap to Point Trend Line

TrendLine.png (31.9 KiB) Viewed 30322 times

2] Semi Log Aware Line
Image 2 shows Line Drawn on series whose Logarithmic Property is Set to True.
Whereas Image 3 shows the same Line on same series whose Logarithmic Property is Set to False.
By clearly looking at both the image, you can clearly make out the difference in Image 3 that the blue line is now has the appearance of Curved Line.
The line shown in Image 3 is actual Semi Log Aware Trend Line.

Image (2): Line Drawn on Logarithmic Series

Semilog_Scale.png (26.35 KiB) Viewed 30304 times

Image (3): Line Drawn on Same Series (with Logarithmic = Off

Without_Semilog_Scale.png (27.33 KiB) Viewed 30306 times

[Christopher]

Quant,

A couple of questions:
1) which algorithm are you using to calculate the points that are drawn in the trendline?
2) the snap to point functionality ... how do you want this to work? Which if the OHLC (open, high, low, close) points do you want the line to snap to when the mouse is moved?

[Quant]

Hi,

Currently we are not using any algorithm for calculating points that are drawn in the trendline. We are using Line Tool for drawing trendline.
I can suggest you algorithm that is TeeChart currently using for Tool "Nearest Point".

For the Snap Point functionality yes we want the line to snap when the mouse is moved.

[Christopher]

Currently we are not using any algorithm for calculating points that are drawn in the trendline. We are using Line Tool for drawing trendline.

Okay ... so how do you expect the line to "bend" as you require? For this to happen more than two points (start, end) are necessary.

I can suggest you algorithm that is TeeChart currently using for Tool "Nearest Point".

Please do not forget that even without the TeeChart source code you have access to this algorithm - the TeeChart.dll is not obfuscated, which means you can easily use tools such as reflector or ILSpy to copy code.

[Quant]

Hi,
We did R&D on the mentioned requirement in this post, but we yet to get solution on this.
Please provide us with some sample code.

[Narcís]

Hello Quant,

To be able to understand which is your exact requirement you should answer the questions Christopher Ireland made you before:

2) the snap to point functionality ... how do you want this to work? Which if the OHLC (open, high, low, close) points do you want the line to snap to when the mouse is moved?

Okay ... so how do you expect the line to "bend" as you require? For this to happen more than two points (start, end) are necessary.

Please do not forget that even without the TeeChart source code you have access to this algorithm - the TeeChart.dll is not obfuscated, which means you can easily use tools such as reflector or ILSpy to copy code.

Did you look at that, which problems did you come across?

Thanks in advance.

[Quant]

Hi,

1] Snap to Point Functionality should work on selected series data. It can be OHLC, Line or Volume etc.

2] I explained the same point in more details (with images), in this post. Yes sometimes we need more than two points to achieve this.

3] Currently we have not looked in your source code, but as we have to deliver these requirements asap, we do not have much time to follow this step. It would be very great if you help us in fulfilling these requirements.

[Narcís]

Hi Quant,

You could try using NearestPoint tool GetNearestPoint method as Yeray explained here to snap points to your series.

[Quant]

Hi,

We need an example for Semi Log Aware Trendline, which we have explained with image in this post.
We did our research on this but still we haven't found any solution.

[Christopher]

Hello,

We did our research on this but still we haven't found any solution.

Can you please explain the specific problems you encountered in your research of this functionality?

My colleague Narcís has been kind enough to produce a simple mock-up of what we understand as your requirement, which is here:

Code: Select all

    private Steema.TeeChart.Styles.Candle candle1;
    private Steema.TeeChart.Tools.NearestPoint nearestPoint1;

    private void InitializeChart()
    {
      tChart1.Aspect.View3D = false;
      tChart1.Zoom.Direction = Steema.TeeChart.ZoomDirections.None;
      tChart1.Panning.Allow = Steema.TeeChart.ScrollModes.None;

      candle1 = new Steema.TeeChart.Styles.Candle(tChart1.Chart);
      candle1.FillSampleValues();

      nearestPoint1 = new Steema.TeeChart.Tools.NearestPoint(candle1);
      nearestPoint1.Active = false;

      tChart1.MouseDown += tChart1_MouseDown;
      tChart1.MouseMove += tChart1_MouseMove;
      tChart1.MouseUp += tChart1_MouseUp;
    }

    void tChart1_MouseUp(object sender, MouseEventArgs e)
    {
      if (!multiPointLine && (index != -1))
      {
        AddNewPoint(new Point(e.X, e.Y));
      }
      index = -1;
    }

    private void AddNewPoint(Point point)
    {
      int newIndex = nearestPoint1.GetNearestPoint(point);
      tChart1[tChart1.Series.Count - 1].Add(candle1.XValues[newIndex], candle1.YValues[newIndex]);
    }

    void tChart1_MouseMove(object sender, MouseEventArgs e)
    {
      if (multiPointLine && (index != -1))
      {
        AddNewPoint(new Point(e.X, e.Y));
      }
    }

    private int index = -1;

    void tChart1_MouseDown(object sender, MouseEventArgs e)
    {
      index = nearestPoint1.GetNearestPoint(new Point(e.X, e.Y));

      if (index != -1)
      {
        tChart1.Series.Add(new Steema.TeeChart.Styles.Line());
        tChart1[tChart1.Series.Count - 1].Add(candle1.XValues[index], candle1.YValues[index]);
      }
    }

    private bool multiPointLine = false;

    private void checkBox1_CheckedChanged(object sender, EventArgs e)
    {
      multiPointLine = checkBox1.Checked;
    }

    private void checkBox2_CheckedChanged(object sender, EventArgs e)
    {
      tChart1.Axes.Left.Logarithmic = checkBox2.Checked;
    }

I hope you can use this very simple example to further explain to us exactly what your requirements are.

[Quant]

Dear Steema,

We checked your code, but it is not what we expected. Last time we explained the same with some screenshots. Please take look of this post once again. If you still have difficulty to understand the same, please let us know.

[Christopher]

We checked your code, but it is not what we expected. Last time we explained the same with some screenshots. Please take look of this post once again. If you still have difficulty to understand the same, please let us know.

Without a mathematical or algorithmic explanation of your requirement, I'm afraid we cannot help. Images are simply not enough as a basis for us to implement it, I'm afraid.

[Quant]

watch this video which explain semi log in Excel
*Line is converted to log curve *
http://www.youtube.com/watch?v=y55VmSIMBjE

for mathematical formula use below link
https://en.wikipedia.org/wiki/Semi-log_plot