[SOLVED]Please help,TaChart learning.
lazarus / 55-TAChart

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Robert W.B. · 2012-03-28 16:36

I tried to learn how to do a simple line chart that's is important to
me.
Can any one give me a code for this chart.

48 bars in my chart.

begin
var
myarray[1..48] of ???  

begin

for a:=1 to 48 do begin
chart1 // show myarray values in  chart1!!!  
end;


end.

Please help.

Best regards
Rob

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Ask · 2012-03-28 17:30

Look at components/tachart/demo for various demo projects.

Start from the basic demo.

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Robert W.B. · 2012-03-28 18:20

Why can't this simple code work!

I have a chart on a form and a button.

procedure TForm1.Button1Click(Sender: TObject);
var
  i:integer;
begin
  for i:=1 to 10 do begin
  Chart1.series.Index:=i; // errormessage= Listindex(0) out of bounds
   end;

end;

end.     

I must be completely stupid !

Can anyone correct the code for me?

Best regards
Rob

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Laksen · 2012-03-28 18:46

Place a TChart and a TUserDefinedChartSource component on the form.
Double click the Chart. This will bring up the "Edit series" window.
Click add, and then select Line series. Select the line series and
change the Source property to the UserDefinedChartSource1 component.
Click the UserDefinedChartSource1. Set the PointsNumber property to 48
Now doubleclick the UserDefinedChartSource1 component. This will give
you the following:

Code: [Select]procedure
TForm1.UserDefinedChartSource1GetChartDataItem(ASource:
TUserDefinedChartSource; AIndex: Integer; var AItem: TChartDataItem);
begin

end;

Simply change that to:
Code: [Select]procedure
TForm1.UserDefinedChartSource1GetChartDataItem(ASource:
TUserDefinedChartSource; AIndex: Integer; var AItem: TChartDataItem);
begin
   AItem.Y := MyArray[AIndex+1]; // AIndex starts from 0, and goes to
47
end;

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tomek · 2012-03-28 18:54

Put TChart on the form, then:
Code: [Select]procedure TForm1.Button1Click(Sender: TObject);
var
  i:integer;
  Bser: TBarSeries;
begin
  Bser:=TBarSeries.Create(Chart1);
  for i:=1 to 48 do
    Bser.Add(i,IntToStr(i),clRed);
  Chart1.AddSeries(Bser);
end;

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Robert W.B. · 2012-03-28 19:21

The code looks nice but,shall i put something in uses?

unit1.pas(37,19) Error: Identifier not found "TBarSeries"
unit1.pas(37,19) Error: Error in type definition
unit1.pas(39,19) Error: Identifier not found "TBarSeries"
unit1.pas(41,10) Error: Illegal qualifier
unit1.pas(42,24) Error: Incompatible type for arg no. 1: Got
"<erroneous type>", expected "TBasicChartSeries"
tagraph.pas(740,18) Hint: Found declaration:
TChart.AddSeries(TBasicChartSeries);
unit1.pas(47) Fatal: There were 5 errors compiling module, stopping

Best regards
Rob

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Robert W.B. · 2012-03-28 19:51

UserDefinedChartsource1 on the form.
Thank you everybody for saving my day.

Best regards
Rob

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tomek · 2012-03-28 19:54

Quote from: robbanux on March 28, 2012, 09:21:44 pmThe code looks nice
but,shall i put something in uses?

TASeries