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unit main;
{$mode objfpc}{$H+}
interface
uses
Classes, SysUtils, FileUtil, TAGraph, TAFuncSeries, TASeries, TATools, Forms,
Controls, Graphics, Dialogs, Types, TAChartUtils;
type
{ TForm1 }
TForm1 = class(TForm)
Chart1: TChart;
Chart1ConstantLine1: TConstantLine;
Chart1ConstantLine2: TConstantLine;
Chart1FuncSeries1: TFuncSeries;
Chart1FuncSeries2: TFuncSeries;
procedure Chart1ExtentValidate(ASender: TChart;
var ALogicalExtent: TDoubleRect; var AllowChange: Boolean);
procedure Chart1FuncSeries1Calculate(const AX: Double; out AY: Double);
procedure Chart1FuncSeries2Calculate(const AX: Double; out AY: Double);
procedure FormCreate(Sender: TObject);
private
procedure UpdateDomainExclusions;
end;
var
Form1: TForm1;
implementation
{$R *.lfm}
uses
Math;
{ TForm1 }
{ In old Lazarus versions you can update the domain exclusions to a new extent
in the OnAfterDrawBackWall event. In Laz 2.1 or later, you can use the event
OnExtentValidate instead - its name is a bit more intuitive... }
(*
procedure TForm1.Chart1AfterDrawBackWall(ASender: TChart; ACanvas: TCanvas;
const ARect: TRect);
begin
Unused(ASender, ACanvas, ARect);
UpdateDomainExclusions;
end;
*)
procedure TForm1.Chart1ExtentValidate(ASender: TChart;
var ALogicalExtent: TDoubleRect; var AllowChange: Boolean);
begin
Unused(ASender, ALogicalExtent, AllowChange);
UpdateDomainExclusions;
end;
procedure TForm1.Chart1FuncSeries1Calculate(const AX: Double; out AY: Double);
begin
AY := tan(AX);
end;
procedure TForm1.Chart1FuncSeries2Calculate(const AX: Double; out AY: Double);
begin
AY := ln(AX);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
with Chart1FuncSeries2.DomainExclusions do begin
AddRange(NegInfinity, 0.0);
end;
end;
procedure TForm1.UpdateDomainExclusions;
var
ex: TDoubleRect;
x: Integer;
begin
ex := Chart1.CurrentExtent;
Chart1.DisableRedrawing;
try
with Chart1FuncSeries1.DomainExclusions do begin
Clear;
for x := Floor(ex.a.x / Pi - 0.5) to Ceil(ex.b.x / Pi + 0.5) do
AddPoint((x + 0.5) * Pi);
end;
finally
Chart1.EnableRedrawing;
end;
end;
end.
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