Steema Central

Code: Select all

uses Series, TeeDownSampling, Math;

var oSeries, dSeries: TFastLineSeries;
    dFunc: TDownSamplingFunction;
    minSector: Integer;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  Chart1.View3D:=False;
  Chart1.Legend.Hide;

  Chart1.Axes.Bottom.Grid.Hide;
  Chart1.Axes.Left.Grid.Hide;
  Chart1.Axes.Left.SetMinMax(0,2000);

  oSeries:=Chart1.AddSeries(TFastLineSeries) as TFastLineSeries;
  with oSeries do
  begin
    Pen.Style:=psDash;

    Add(1000);
    for i:=0 to 400-1 do
      Add(YValue[Count-1]+Random*10-5);

    Active:=False;
  end;

  dSeries:=Chart1.AddSeries(TFastLineSeries) as TFastLineSeries;
  dFunc:=TDownSamplingFunction.Create(Self);
  dFunc.DownSampleMethod:=dsAverage;
  dSeries.SetFunction(dFunc);
  dSeries.Pen.Style:=oSeries.Pen.Style;
  dSeries.Color:=oSeries.Color;
  dSeries.DataSource:=oSeries;
  dSeries.CheckDataSource;

  Chart1.OnZoom:=ChartZoom;
  Chart1.OnUndoZoom:=ChartUndoZoom;

  CalcTolerance;
end;


procedure TForm1.ChartZoom(Sender: TObject);
begin
  CalcTolerance;
end;

procedure TForm1.ChartUndoZoom(Sender: TObject);
begin
  CalcTolerance;
end;

procedure TForm1.CalcTolerance;
begin
  dFunc.Tolerance:=1;
  Chart1.Draw;

  if dSeries.Count>0 then
    while (Chart1.ChartRect.Right-Chart1.ChartRect.Left) div (dSeries.LastDisplayedIndex-dSeries.FirstDisplayedIndex) < 5 do
    begin
      dFunc.Tolerance:=dFunc.Tolerance+1;
      dSeries.CalcFirstLastVisibleIndex;
    end;

  Caption:=FormatFloat('#,##0', dFunc.Tolerance);
end;

Code: Select all

uses Series, TeeDownSampling;

var dFunc: TDownSamplingFunction;
    dSeries: TFastLineSeries;

procedure TForm1.FormCreate(Sender: TObject);
var i: Integer;
begin
  Chart1.Legend.Hide;
  Chart1.View3D:=False;
  Chart1.Hover.Visible:=False;

  Chart1.Axes.Left.EndPosition:=33;
  Chart1.Axes.Left.Title.Caption:='Original';

  with Chart1.CustomAxes.Add do
  begin
    StartPosition:=33;
    EndPosition:=66;
    LabelsFont.Assign(Chart1.Axes.Left.LabelsFont);
    Title.Font.Assign(Chart1.Axes.Left.Title.Font);
    Title.Caption:='DrawStyle=flAll';
  end;
  with Chart1.CustomAxes.Add do
  begin
    StartPosition:=66;
    LabelsFont.Assign(Chart1.Axes.Left.LabelsFont);
    Title.Font.Assign(Chart1.Axes.Left.Title.Font);
    Title.Caption:='DownSampling';
  end;

  for i:=0 to 2 do
  begin
    with Chart1.AddSeries(TFastLineSeries) as TFastLineSeries do
    begin
      if i=0 then
        FillSampleValues(10000)
      else
      begin
        DataSource:=Chart1[0];
        CustomVertAxis:=Chart1.CustomAxes[i-1];
        Color:=Chart1[0].Color;

        if i=1 then
          DrawStyle:=flAll
        else if i=2 then
        begin
          dSeries:=Chart1[i] as TFastLineSeries;
          dFunc:=TDownSamplingFunction.Create(Self);
          dFunc.DownSampleMethod:=dsAverage;
          dSeries.SetFunction(dFunc);
        end;
      end;

      Pen.Style:=psDash;
    end;
  end;

  CalcTolerance;
end;

procedure TForm1.CalcTolerance;
begin
  dFunc.Tolerance:=1;
  Chart1.Draw;

  if dSeries.Count>0 then
    while (Chart1.ChartRect.Right-Chart1.ChartRect.Left) div (dSeries.LastDisplayedIndex-dSeries.FirstDisplayedIndex) < 5 do
    begin
      dFunc.Tolerance:=dFunc.Tolerance+1;
      dSeries.CalcFirstLastVisibleIndex;
    end;

  Caption:='DownSampling Tolerance: ' + FormatFloat('#,##0', dFunc.Tolerance);
end;

Code: Select all

uses Series, Diagnostics;

const nValues=10000;
      nPoints=10;

var Stopwatch: TStopwatch;
    tmp1, tmp2: Double;

procedure TForm1.Chart1AfterDraw(Sender: TObject);
begin
  tmp1:=Stopwatch.Elapsed.TotalMilliseconds;
  tmp2:=Stopwatch.Elapsed.TotalSeconds;

  if Stopwatch.Elapsed.TotalSeconds>1 then
     Caption:=FormatFloat('#,##0.##', Stopwatch.Elapsed.TotalSeconds)+'s'
  else
     Caption:=FormatFloat('#,##0.##', Stopwatch.Elapsed.TotalMilliseconds)+'ms';
end;

procedure TForm1.Chart1BeforeDrawChart(Sender: TObject);
begin
  Stopwatch := TStopwatch.StartNew;
end;

procedure TForm1.FormCreate(Sender: TObject);
var i, j: Integer;
    diff: Double;
begin
  Chart1.View3D:=False;
  Chart1.Legend.Hide;
  Chart1.Title.Hide;
  Chart1.Hover.Visible:=False;

  (Chart1.AddSeries(TPointSeries) as TPointSeries).Pointer.Size:=2;

  diff:=nValues/nPoints;

  for i:=0 to 9 do
  begin
    Chart1.AddSeries(TLineSeries).FillSampleValues(nValues);
    //Chart1.AddSeries(TFastLineSeries).FillSampleValues(nValues);

    j:=0;
    repeat
      Chart1[0].AddXY(j*diff, Chart1[Chart1.SeriesCount-1].YValue[round(j*diff)], '', Chart1[Chart1.SeriesCount-1].Color);
      Inc(j);
    until (j*diff>=nValues);

  end;

  Chart1.ExchangeSeries(0, Chart1.SeriesCount-1);
end;