Trying to plot points, but the plot sizes can't be adjusted.

[garymq]

Hello.
I am plotting points on a chart. I do not want lines, I want separate dots.

The code is below.

I can of course use lines to make the graph, and I can adjust the width.
But there are gaps in the data, and if I use lines ( S2.LineType := ltFromPrevious;), the lines automatically join up between dots, and I don't see any gaps. I don't want that.

So I use Pointer.Style, either "S2.Pointer.Style := psPoint;" or "S2.Pointer.Style := psCircle;"

This works, but here's the problem (as shown in the attached screenshots):
S2.Pointer.Style := psPoint; is too thin, and I can barely see the line.
S2.Pointer.Style := psCircle; is too thick.

The only other Pointer styles are stars, diamonds, or other shapes, none of which are suitable.

So my question is: How can I just plot dots, and be able to adjust the size of the points?
(Alternatives are to have another, smaller, Pointer style; or  to be able to make the size of psCircle smaller.)

Code: Pascal  [Select][+][-]

1. procedure TFrm_AquaView.ReadGraphTideFile(InputFile: String);
2. { Read in and plot the tide file.
3. InputFile: tide file (e.g. BWPR01_HHMMYYYY.tid)
4. }
5. var
6.   List1: TStringList;
7.   i1: Integer=0;
8.   tidecount: Integer=0;
9.   st1,st2: String;
10.   S2: TLineSeries;
11.   X2: Double;
12.   Minutes, Hours: Integer;
13.  
14. begin
15.  Chart1.ClearSeries;
16.  S2 := TLineSeries.Create(Chart1);
17.  S2.ShowLines:=True;
18.  S2.ShowPoints:=False;
19.  S2.Pointer.Visible:=True;
20.  s2.LinePen.Width:=2;
21.  
22.  S2.ShowPoints := True;
23.  S2.LineType := ltNone;
24.  S2.Pointer.Style := psCircle;
25. // S2.Pointer.Style := psPoint;
26.  S2.Pointer.Brush.Color := clBlack;
27.  S2.Pointer.Pen.Color := clBlack;          
28.  

[CM630]

This shows only points and no lines.

Code: Pascal  [Select][+][-]

1. ...
2. uses ... TATypes...
3. ...
4.  
5. procedure TForm1.Button1Click(Sender:TObject);
6. var
7.   i: integer = 0;
8. begin
9.   S2.LinePen.Style := psClear;
10.   S2.ShowPoints := True;
11.   S2.Pointer.Style := psCircle;
12.   S2.Pointer.HorizSize :=2;
13.   S2.Pointer.VertSize :=2;
14.   S2.Pointer.Visible := True;
15.   S2.Pointer.Brush.Color := clBlack; //fill the circle in
16.   for i := 0 to 10 do
17.     S2.Add(i);
18. end;  

   

[Warfley]

While you can certainly solve this with TAChart, and someone already posted a solution, I personally prefer to just create my own plots using a Canvas. It's fairly easy and you can tweak them to your liking in a way some library often doesn't.

As an example, some time ago I've written the following tool for some work I was doing at the time, which required me to plot a bunch of different measures and compute the 95% confidence interval. The drawing is just like a hundred lines of code, making the plot zoom and draggable just a few lines more. You can check out the code here: https://github.com/Warfley/KleeSummary/blob/master/Forms/Tools/Plot/statsplotframe.pas

[garymq]

Hey
You added:

  S2.Pointer.HorizSize :=2;
  S2.Pointer.VertSize :=2;

That's just what I wanted.
So simple, but somehow I missed these parameters. There are so many options..
Thanks!