LazStats: Inherit form in CorSimUnit from TBasicStatsReportAndChartForm. Use TAChart.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7784 8e941d3f-bd1b-0410-a28a-d453659cc2b4

applications/lazstats/source/LazStats.lpi

@@ -809,7 +809,7 @@
       <Unit88>
         <Filename Value="forms\simulations\corsimunit.pas"/>
         <IsPartOfProject Value="True"/>
-        <ComponentName Value="CorSimFrm"/>
+        <ComponentName Value="CorSimForm"/>
         <HasResources Value="True"/>
         <ResourceBaseClass Value="Form"/>
         <UnitName Value="CorSimUnit"/>

applications/lazstats/source/forms/mainunit.pas

@@ -1373,9 +1373,9 @@ end;
 // Menu "Simulations" > "Bivariate Scatter Plot"
 procedure TOS3MainFrm.mnuSimBivarScatterPlotClick(Sender: TObject);
 begin
-  if CorSimFrm = nil then
+  if CorSimForm = nil then
-    Application.CreateForm(TCorSimFrm, CorSimFrm);
+    Application.CreateForm(TCorSimForm, CorSimForm);
-  CorSimFrm.ShowModal;
+  CorSimForm.Show;
 end;
 
 // Menu "Simulations" > "Chisquare Probability"

applications/lazstats/source/forms/simulations/corsimunit.lfm

@@ -1,4 +1,4 @@
-object CorSimFrm: TCorSimFrm
+inherited CorSimForm: TCorSimForm
   Left = 542
   Height = 447
   Top = 126
@@ -8,223 +8,263 @@ object CorSimFrm: TCorSimFrm
   Caption = 'Correlation Simulation'
   ClientHeight = 447
   ClientWidth = 857
-  OnShow = FormShow
+  inherited ParamsPanel: TPanel
-  Position = poMainFormCenter
+    Height = 431
-  LCLVersion = '2.1.0.0'
+    Width = 267
-  object Image1: TImage
+    ClientHeight = 431
-    Left = 8
+    ClientWidth = 267
-    Height = 389
+    inherited CloseBtn: TButton
-    Top = 8
+      Left = 212
-    Width = 841
+      Top = 406
-    Align = alClient
+      TabOrder = 10
-    BorderSpacing.Left = 8
-    BorderSpacing.Top = 8
-    BorderSpacing.Right = 8
     end
-  object Panel1: TPanel
+    inherited ComputeBtn: TButton
-    AnchorSideTop.Side = asrCenter
+      Left = 128
-    Left = 8
+      Top = 406
-    Height = 26
+      TabOrder = 9
-    Top = 413
+    end
-    Width = 841
+    inherited ResetBtn: TButton
-    Align = alBottom
+      Left = 66
-    AutoSize = True
+      Top = 406
-    BorderSpacing.Around = 8
+      TabOrder = 8
-    BevelOuter = bvNone
+    end
-    ClientHeight = 26
+    inherited HelpBtn: TButton
-    ClientWidth = 841
+      Left = 7
-    TabOrder = 0
+      Top = 406
-    object Label1: TLabel
+      TabOrder = 7
-      AnchorSideLeft.Control = Panel1
+      Visible = False
-      AnchorSideTop.Control = MeanX
+    end
+    inherited ButtonBevel: TBevel
+      Top = 390
+      Width = 267
+    end
+    object Label1: TLabel[5]
+      AnchorSideLeft.Control = ParamsPanel
+      AnchorSideTop.Control = MeanXEdit
       AnchorSideTop.Side = asrCenter
       Left = 0
       Height = 15
-      Top = 6
+      Top = 4
       Width = 43
       Caption = 'Mean X:'
       ParentColor = False
     end
-    object Label2: TLabel
+    object MeanXEdit: TEdit[6]
-      AnchorSideLeft.Control = MeanX
+      AnchorSideLeft.Control = Label1
       AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Label1
+      AnchorSideTop.Control = ParamsPanel
-      Left = 108
+      Left = 51
+      Height = 23
+      Top = 0
+      Width = 60
+      Alignment = taRightJustify
+      BorderSpacing.Left = 8
+      TabOrder = 0
+      Text = 'MeanXEdit'
+    end
+    object Label2: TLabel[7]
+      AnchorSideLeft.Control = ParamsPanel
+      AnchorSideTop.Control = MeanYEdit
+      AnchorSideTop.Side = asrCenter
+      Left = 0
       Height = 15
-      Top = 6
+      Top = 35
       Width = 43
-      BorderSpacing.Left = 16
       Caption = 'Mean Y:'
       ParentColor = False
     end
-    object Label3: TLabel
+    object MeanYEdit: TEdit[8]
-      AnchorSideLeft.Control = MeanY
+      AnchorSideLeft.Control = MeanXEdit
+      AnchorSideTop.Control = MeanXEdit
+      AnchorSideTop.Side = asrBottom
+      AnchorSideRight.Control = MeanXEdit
+      AnchorSideRight.Side = asrBottom
+      Left = 51
+      Height = 23
+      Top = 31
+      Width = 60
+      Alignment = taRightJustify
+      Anchors = [akTop, akLeft, akRight]
+      BorderSpacing.Top = 8
+      TabOrder = 2
+      Text = 'MeanYEdit'
+    end
+    object Label3: TLabel[9]
+      AnchorSideLeft.Control = MeanXEdit
       AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Label2
+      AnchorSideTop.Control = StdDevXEdit
-      Left = 221
+      AnchorSideTop.Side = asrCenter
+      Left = 135
       Height = 15
-      Top = 6
+      Top = 4
       Width = 50
-      BorderSpacing.Left = 16
+      BorderSpacing.Left = 24
       Caption = 'Std.Dev.X'
       ParentColor = False
     end
-    object Label4: TLabel
+    object StdDevXEdit: TEdit[10]
-      AnchorSideLeft.Control = SDX
+      AnchorSideLeft.Control = Label3
       AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Label3
+      AnchorSideTop.Control = ParamsPanel
-      Left = 345
+      Left = 193
+      Height = 23
+      Top = 0
+      Width = 60
+      Alignment = taRightJustify
+      BorderSpacing.Left = 8
+      TabOrder = 1
+      Text = 'StdDevXEdit'
+    end
+    object Label4: TLabel[11]
+      AnchorSideLeft.Control = Label3
+      AnchorSideTop.Control = StdDevYEdit
+      AnchorSideTop.Side = asrCenter
+      Left = 135
       Height = 15
-      Top = 6
+      Top = 35
       Width = 50
-      BorderSpacing.Left = 16
       Caption = 'Std.Dev.Y'
       ParentColor = False
     end
-    object Label5: TLabel
+    object StdDevYEdit: TEdit[12]
-      AnchorSideLeft.Control = SDY
+      AnchorSideLeft.Control = StdDevXEdit
+      AnchorSideTop.Control = MeanYEdit
+      AnchorSideRight.Control = StdDevXEdit
+      AnchorSideRight.Side = asrBottom
+      Left = 193
+      Height = 23
+      Top = 31
+      Width = 60
+      Alignment = taRightJustify
+      Anchors = [akTop, akLeft, akRight]
+      TabOrder = 3
+      Text = 'StdDevYEdit'
+    end
+    object Label5: TLabel[13]
       AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Label4
+      AnchorSideTop.Control = CorrEdit
-      Left = 450
+      AnchorSideTop.Side = asrCenter
+      AnchorSideRight.Control = CorrEdit
+      Left = 51
       Height = 15
-      Top = 6
+      Top = 82
-      Width = 36
+      Width = 76
+      Anchors = [akTop, akRight]
       BorderSpacing.Left = 8
-      Caption = 'Cor.XY'
+      BorderSpacing.Right = 8
+      Caption = 'Correlation XY'
       ParentColor = False
     end
-    object Label6: TLabel
+    object CorrEdit: TEdit[14]
-      AnchorSideLeft.Control = Corr
+      AnchorSideLeft.Control = Label3
+      AnchorSideTop.Control = MeanYEdit
+      AnchorSideTop.Side = asrBottom
+      Left = 135
+      Height = 23
+      Top = 78
+      Width = 60
+      Alignment = taRightJustify
+      BorderSpacing.Top = 24
+      TabOrder = 4
+      Text = 'CorrEdit'
+    end
+    object Label6: TLabel[15]
       AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Label5
+      AnchorSideTop.Control = NumObsEdit
       AnchorSideTop.Side = asrCenter
-      Left = 554
+      AnchorSideRight.Control = NumObsEdit
+      Left = 92
       Height = 15
-      Top = 6
+      Top = 113
       Width = 35
+      Anchors = [akTop, akRight]
       BorderSpacing.Left = 16
+      BorderSpacing.Right = 8
       Caption = 'N Size:'
       ParentColor = False
     end
-    object MeanX: TEdit
+    object NumObsEdit: TEdit[16]
-      AnchorSideLeft.Control = Label1
+      AnchorSideLeft.Control = CorrEdit
-      AnchorSideLeft.Side = asrBottom
+      AnchorSideTop.Control = CorrEdit
-      AnchorSideTop.Control = Panel1
+      AnchorSideTop.Side = asrBottom
-      AnchorSideTop.Side = asrCenter
+      AnchorSideRight.Control = CorrEdit
-      Left = 49
-      Height = 23
-      Top = 2
-      Width = 43
-      Alignment = taRightJustify
-      BorderSpacing.Left = 6
-      OnKeyPress = MeanXKeyPress
-      TabOrder = 0
-      Text = 'MeanX'
-    end
-    object MeanY: TEdit
-      AnchorSideLeft.Control = Label2
-      AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = MeanX
-      Left = 159
-      Height = 23
-      Top = 2
-      Width = 46
-      Alignment = taRightJustify
-      BorderSpacing.Left = 8
-      OnKeyPress = MeanYKeyPress
-      TabOrder = 1
-      Text = 'MeanY'
-    end
-    object SDX: TEdit
-      AnchorSideLeft.Control = Label3
-      AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = MeanY
-      Left = 279
-      Height = 23
-      Top = 2
-      Width = 50
-      Alignment = taRightJustify
-      BorderSpacing.Left = 8
-      OnKeyPress = SDXKeyPress
-      TabOrder = 2
-      Text = 'SDX'
-    end
-    object SDY: TEdit
-      AnchorSideLeft.Control = Label4
-      AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = SDX
-      Left = 403
-      Height = 23
-      Top = 2
-      Width = 39
-      Alignment = taRightJustify
-      BorderSpacing.Left = 8
-      OnKeyPress = SDYKeyPress
-      TabOrder = 3
-      Text = 'SDY'
-    end
-    object Corr: TEdit
-      AnchorSideLeft.Control = Label5
-      AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = SDY
-      Left = 494
-      Height = 23
-      Top = 2
-      Width = 44
-      Alignment = taRightJustify
-      BorderSpacing.Left = 8
-      OnKeyPress = CorrKeyPress
-      TabOrder = 4
-      Text = 'Corr'
-    end
-    object ComputeBtn: TButton
-      AnchorSideTop.Control = CloseBtn
-      AnchorSideRight.Control = CloseBtn
-      Left = 702
-      Height = 26
-      Top = 0
-      Width = 65
-      Anchors = [akTop, akRight]
-      BorderSpacing.Right = 8
-      Caption = 'Compute'
-      OnClick = ComputeBtnClick
-      TabOrder = 6
-    end
-    object CloseBtn: TButton
-      AnchorSideTop.Control = Panel1
-      AnchorSideTop.Side = asrCenter
-      AnchorSideRight.Control = Panel1
       AnchorSideRight.Side = asrBottom
-      Left = 775
+      Left = 135
-      Height = 26
-      Top = 0
-      Width = 66
-      Anchors = [akTop, akRight]
-      Caption = 'Close'
-      ModalResult = 11
-      TabOrder = 7
-    end
-    object Nobs: TEdit
-      AnchorSideLeft.Control = Label6
-      AnchorSideLeft.Side = asrBottom
-      AnchorSideTop.Control = Corr
-      Left = 597
       Height = 23
-      Top = 2
+      Top = 109
-      Width = 40
+      Width = 60
       Alignment = taRightJustify
-      BorderSpacing.Left = 8
+      Anchors = [akTop, akLeft, akRight]
-      OnKeyPress = NobsKeyPress
+      BorderSpacing.Top = 8
       TabOrder = 5
-      Text = 'Nobs'
+      Text = 'NumObsEdit'
     end
-  end
+    object PlotOptionsGroup: TGroupBox[17]
-  object Bevel1: TBevel
+      AnchorSideLeft.Control = ParamsPanel
+      AnchorSideTop.Control = NumObsEdit
+      AnchorSideTop.Side = asrBottom
       Left = 0
-    Height = 8
+      Height = 90
-    Top = 397
+      Top = 148
-    Width = 857
+      Width = 178
-    Align = alBottom
+      AutoSize = True
-    Shape = bsBottomLine
+      BorderSpacing.Top = 16
+      Caption = 'Plot options'
+      ClientHeight = 70
+      ClientWidth = 174
+      TabOrder = 6
+      object NumBinsEdit: TSpinEdit
+        AnchorSideLeft.Control = Label7
+        AnchorSideLeft.Side = asrBottom
+        AnchorSideTop.Control = PlotOptionsGroup
+        Left = 107
+        Height = 23
+        Top = 8
+        Width = 55
+        BorderSpacing.Left = 8
+        BorderSpacing.Top = 8
+        BorderSpacing.Right = 12
+        MinValue = 2
+        OnChange = NumBinsEditChange
+        TabOrder = 0
+        Value = 2
+      end
+      object Label7: TLabel
+        AnchorSideLeft.Control = PlotOptionsGroup
+        AnchorSideTop.Control = NumBinsEdit
+        AnchorSideTop.Side = asrCenter
+        Left = 16
+        Height = 15
+        Top = 12
+        Width = 83
+        BorderSpacing.Left = 16
+        Caption = 'Number of bins'
+        ParentColor = False
+      end
+      object BinCountChk: TCheckBox
+        AnchorSideLeft.Control = Label7
+        AnchorSideTop.Control = NumBinsEdit
+        AnchorSideTop.Side = asrBottom
+        Left = 16
+        Height = 19
+        Top = 39
+        Width = 113
+        BorderSpacing.Top = 8
+        BorderSpacing.Bottom = 12
+        Caption = 'Show frequencies'
+        OnChange = BinCountChkChange
+        TabOrder = 1
+      end
+    end
+  end
+  inherited ParamsSplitter: TSplitter
+    Left = 279
+    Height = 447
+  end
+  inherited PageControl: TPageControl
+    Left = 288
+    Height = 431
+    Width = 561
+    TabOrder = 1
   end
 end

applications/lazstats/source/forms/simulations/corsimunit.pas

@@ -5,462 +5,491 @@ unit CorSimUnit;
 interface
 
 uses
-  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
+  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs,
-  ExtCtrls, StdCtrls, Math,
+  ExtCtrls, StdCtrls, ComCtrls, Spin,
-  Globals, OutputUnit;
+  TAGraph, TACustomSeries,
+  Globals, BasicStatsReportAndChartFormUnit;
 
 type
 
-  { TCorSimFrm }
+  TCorSimResult = record
+    a, b: Double;
+    xMean, xStdDev: Double;
+    yMean, yStdDev: Double;
+    CorrXY: Double;
+  end;
 
-  TCorSimFrm = class(TForm)
+  { TCorSimForm }
-    Bevel1: TBevel;
+
-    Nobs: TEdit;
+  TCorSimForm = class(TBasicStatsReportAndChartForm)
-    Image1: TImage;
+    BinCountChk: TCheckBox;
+    Label7: TLabel;
+    PlotOptionsGroup: TGroupBox;
+    NumObsEdit: TEdit;
     Label6: TLabel;
-    CloseBtn: TButton;
+    CorrEdit: TEdit;
-    ComputeBtn: TButton;
-    Corr: TEdit;
     Label5: TLabel;
-    SDY: TEdit;
+    NumBinsEdit: TSpinEdit;
+    StdDevYEdit: TEdit;
     Label4: TLabel;
-    SDX: TEdit;
+    StdDevXEdit: TEdit;
     Label3: TLabel;
-    MeanY: TEdit;
+    MeanYEdit: TEdit;
     Label2: TLabel;
-    MeanX: TEdit;
+    MeanXEdit: TEdit;
     Label1: TLabel;
-    Panel1: TPanel;
+    procedure BinCountChkChange(Sender: TObject);
-    procedure ComputeBtnClick(Sender: TObject);
+    procedure NumBinsEditChange(Sender: TObject);
-    procedure CorrKeyPress(Sender: TObject; var Key: char);
-    procedure FormShow(Sender: TObject);
-    procedure MeanXKeyPress(Sender: TObject; var Key: char);
-    procedure MeanYKeyPress(Sender: TObject; var Key: char);
-    procedure NobsKeyPress(Sender: TObject; var Key: char);
-    procedure SDXKeyPress(Sender: TObject; var Key: char);
-    procedure SDYKeyPress(Sender: TObject; var Key: char);
   private
-    { private declarations }
+    XHistogramChart: TChart;
-    xmean, ymean, xsd, ysd, corxy, corsqr, yvariance, predvar : double;
+    YHistogramChart: TChart;
-    errvariance, stderror, b, constant, newxmean, newymean : double;
+    XHistogramSeries: TChartSeries;
-    newxsd, newysd, newcorr, randomerror, newb, newconstant : double;
+    YHistogramSeries: TChartSeries;
-    x, y: DblDyneVec;
+    xValues, yValues: DblDyneVec;
-    freqx, freqy: IntDyneVec;
+    simResult: TCorSimResult;
-    N: integer;
+
+    procedure ChartAfterPaint(Sender: TChart);
+    procedure ChartFrameResize(Sender: TObject);
+
+    procedure GenerateData(ACount: Integer;
+      const XMean, YMean, XStdDev, YStdDev, CorrXY: Double; out A, B: Double);
+
     procedure Plot;
-    function Validate(out AMsg: String; out AControl: TWinControl): Boolean;
+
+    procedure WriteReport(A, B, XMean, YMean, XStdDev, YStdDev, CorrXY: Double);
+
+  protected
+    procedure AdjustConstraints; override;
+    procedure Compute; override;
+    function Validate(out AMsg: String; out AControl: TWinControl): Boolean; override;
+
   public
-    { public declarations }
+    constructor Create(AOwner: TComponent); override;
+    procedure Reset; override;
   end; 
 
 var
-  CorSimFrm: TCorSimFrm;
+  CorSimForm: TCorSimForm;
+
 
 implementation
 
-{ TCorSimFrm }
+{$R *.lfm}
 
-procedure TCorSimFrm.MeanXKeyPress(Sender: TObject; var Key: char);
+uses
+  Math,
+  TAGeometry, TAChartUtils, TALegend, TASeries,
+  MatrixUnit, ChartFrameUnit;
+
+
+{ TCorSimForm }
+
+constructor TCorSimForm.Create(AOwner: TComponent);
 begin
-  if Key = #13 then MeanY.SetFocus;
+  inherited;
+
+  FChartFrame.OnResize := @ChartFrameResize;
+  FChartFrame.Chart.OnAfterPaint := @ChartAfterPaint;
+  FChartFrame.Chart.Foot.Alignment := taLeftJustify;
+
+  XHistogramChart := TChart.Create(FChartFrame);
+  with XHistogramChart do
+  begin
+    Parent := FChartFrame;
+    AnchorSideTop.Control := FChartFrame.ChartToolBar;
+    AnchorSideTop.Side := asrBottom;
+    AnchorSideLeft.Control := FChartFrame.Chart;
+    AnchorSideRight.Control := FChartFrame.Chart;
+    AnchorSideRight.Side := asrBottom;
+    Anchors := [akLeft, akTop, akRight];
+    Height := 200;
+    Color := FChartFrame.Chart.Color;
+    BackColor := FChartFrame.Chart.Color;
+    Margins.Bottom := 0;
+    Frame.Visible := false;
+    LeftAxis.Visible := false;
+    BottomAxis.Grid.Visible := false;
+    BottomAxis.Marks.Visible := false;
+    BottomAxis.AxisPen.Visible := true;
   end;
 
-procedure TCorSimFrm.CorrKeyPress(Sender: TObject; var Key: char);
+  XHistogramSeries := TBarSeries.Create(FChartFrame);
+  with TBarSeries(XHistogramSeries) do
   begin
-  if Key = #13 then Nobs.SetFocus;
+    BarBrush.Color := DATA_COLORS[1];
+    MarkPositions := lmpPositive;
+  end;
+  XHistogramChart.AddSeries(XHistogramSeries);
+
+  YHistogramChart := TChart.Create(FChartFrame);
+  with YHistogramChart do
+  begin
+    Parent := FChartFrame;
+    AnchorSideTop.Control := FChartFrame.Chart;
+    AnchorSideRight.Control := FChartFrame;
+    AnchorSideRight.Side := asrBottom;
+    AnchorSideBottom.Control := FChartFrame.Chart;
+    AnchorSideBottom.Side := asrBottom;
+    Anchors := [akTop, akRight, akBottom];
+    Width := 200;
+    Color := FChartFrame.Chart.Color;
+    BackColor := FChartFrame.Chart.Color;
+    Margins.Left := 0;
+    Frame.Visible := false;
+    BottomAxis.Visible := false;
+    LeftAxis.Grid.Visible := false;
+    LeftAxis.Marks.Visible := false;
+    LeftAxis.AxisPen.Visible := true;
   end;
 
-procedure TCorSimFrm.ComputeBtnClick(Sender: TObject);
+  YHistogramSeries := TBarSeries.Create(FChartFrame);
+  with TBarSeries(YHistogramSeries) do
+  begin
+    AxisIndexX := 0;
+    AxisIndexY := 1;
+    BarBrush.Color := DATA_COLORS[2];
+    MarkPositions := lmpPositive;
+  end;
+  YHistogramChart.AddSeries(YHistogramSeries);
+
+  with FChartFrame.Chart do
+  begin
+    Align := alNone;
+    AnchorSideLeft.Control := FChartFrame;
+    AnchorSideBottom.Control := FChartFrame;
+    AnchorSideBottom.Side := asrBottom;
+    AnchorSideTop.Control := XHistogramChart;
+    AnchorSideTop.Side := asrBottom;
+    AnchorSideRight.Control := YHistogramChart;
+    Anchors := [akLeft, akTop, akRight, akBottom];
+  end;
+
+  PageControl.ActivePageIndex := 0;
+end;
+
+
+procedure TCorSimForm.AdjustConstraints;
+begin
+  inherited;
+
+  ParamsPanel.Constraints.MinWidth := Max(
+    3*CloseBtn.Width + 2*CloseBtn.BorderSpacing.Left,
+    StdDevXEdit.Left + StdDevXEdit.Width
+  );
+  ParamsPanel.Constraints.MinHeight :=
+    PlotOptionsGroup.Top + PlotOptionsGroup.Height +
+    ButtonBevel.Height + CloseBtn.BorderSpacing.Top + CloseBtn.Height;
+end;
+
+
+procedure TCorSimForm.BinCountChkChange(Sender: TObject);
+begin
+  if BinCountChk.Checked then
+  begin
+    XHistogramSeries.Marks.Style := smsValue;
+    YHistogramSeries.Marks.Style := smsValue;
+  end else
+  begin
+    XHistogramSeries.Marks.Style := smsNone;
+    YHistogramSeries.Marks.Style := smsNone;
+  end;
+end;
+
+
+procedure TCorSimForm.ChartAfterPaint(Sender: TChart);
 var
-  i: integer;
+  ext: TDoubleRect;
-  msg: String;
+  R: Trect;
-  C: TWinControl;
-  lReport: TStrings;
 begin
-  if not Validate(msg, C) then begin
+  ext := FChartFrame.Chart.CurrentExtent;
-    C.SetFocus;
+  R.TopLeft := FChartFrame.Chart.GraphToImage(DoublePoint(ext.a.x, ext.b.y));
-    MessageDlg(msg, mtError, [mbOk], 0);
+  R.BottomRight := FChartFrame.Chart.GraphToImage(DoublePoint(ext.b.x, ext.a.y));
-    exit;
+  XHistogramChart.BorderSpacing.Left := R.Left;
+  XHistogramChart.BorderSpacing.Right := FChartFrame.Chart.Width - R.Right;
+  YHistogramChart.BorderSpacing.Top := R.Top;
+  YHistogramChart.BorderSpacing.Bottom := FChartFrame.Chart.Height - R.Bottom;
 end;
 
-  N :=  StrToInt(NObs.Text);
-  xmean := StrToFloat(MeanX.Text);
-  ymean := StrToFloat(MeanY.Text);
-  xsd := StrToFloat(SDX.Text);
-  ysd := StrToFloat(SDY.Text);
-  corxy := StrToFloat(Corr.Text);
 
+procedure TCorSimForm.ChartFrameResize(Sender: TObject);
+begin
+  XHistogramChart.Height := Min(FChartFrame.Width div 5, FChartFrame.Height div 5);
+  YHistogramChart.Width := XHistogramChart.Height;
+end;
+
+
+procedure TCorSimForm.Compute;
+var
+  N: Integer;
+  a, b: Double;
+  xMean, yMean, xStdDev, yStdDev, corrXY: Double;
+begin
+  N :=  StrToInt(NumObsEdit.Text);
+  xMean := StrToFloat(MeanXEdit.Text);
+  yMean := StrToFloat(MeanYEdit.Text);
+  xStdDev := StrToFloat(StdDevXEdit.Text);
+  yStdDev := StrToFloat(StdDevYEdit.Text);
+  corrXY := StrToFloat(CorrEdit.Text);
+
+  GenerateData(N, xMean, yMean, xStdDev, yStdDev, corrXY, a, b);
+
+  with SimResult do
+  begin
+    VecMeanStdDev(xValues, XMean, XStdDev);
+    VecMeanStdDev(yValues, YMean, YStdDev);
+    SimResult.CorrXY := (xValues * yValues - XMean * YMean * N) / ((N-1) * XStdDev * YStdDev);
+    B :=  CorrXY * (YStdDev / XStdDev);
+    A :=  YMean - B * XMean;
+  end;
+
+  WriteReport(a, b, xMean, yMean, xStdDev, yStdDev, corrXY);
+  Plot;
+end;
+
+
+procedure TCorSimForm.GenerateData(ACount: Integer;
+  const XMean, YMean, XStdDev, YStdDev, CorrXY: Double; out A, B: Double);
+var
+  corrSqr, yVariance, predVariance, errVariance, stdError: Double;
+  i: Integer;
+begin
   Randomize;
 
-  SetLength(freqx, N + 1);
+  // Calculate the fitted line parameters
-  SetLength(freqy, N + 1);
+  B := CorrXY * (YStdDev / XStdDev);
-  SetLength(x, N + 1);
+  A := YMean - B * XMean;
-  SetLength(y, N + 1);
 
-  // generate x and y data observations
+  // Calculate the "scatter" parameters
-  corsqr :=  corxy * corxy;
+  corrSqr :=  sqr(CorrXY);
-  yvariance :=  ysd * ysd;
+  yVariance :=  YStdDev * YStdDev;
-  predvar :=  corsqr * yvariance;
+  predVariance :=  corrSqr * yVariance;
-  errvariance :=  yvariance - predvar;
+  errVariance :=  yVariance - predVariance;
-  stderror :=  sqrt(errvariance);
+  stdError :=  sqrt(errVariance);
-  b :=  corxy * (ysd / xsd);
-  constant :=  ymean - b * xmean;
 
-  newxmean :=  0.0;
+  // Calculate x and y values
-  newymean :=  0.0;
+  xValues := nil;
-  newxsd :=  0.0;
+  yValues := nil;
-  newysd :=  0.0;
+  SetLength(xValues, ACount);
-  newcorr :=  0.0;
+  SetLength(yValues, ACount);
-  for i := 1 to N do
+  for i := 0 to ACount-1 do
   begin
-    x[i] :=  RandG(xmean, xsd);
+    xValues[i] :=  RandG(xMean, xStdDev);
-    randomerror :=  RandG(0.0, stderror);
+    yValues[i] :=  A + B * xValues[i] + RandG(0.0, stdError);
-    y[i] :=  b * x[i] + constant + randomerror;
-    newxmean := newxmean + x[i];
-    newymean := newymean + y[i];
-    newxsd := newxsd + sqr(x[i]);
-    newysd := newysd + sqr(y[i]);
-    newcorr := newcorr + x[i] * y[i];
-  end;
-
-  newxsd := newxsd - sqr(newxmean) / N;
-  newxsd := newxsd / (N - 1);
-  newxsd := sqrt(newxsd);
-
-  newysd := newysd - sqr(newymean) / N;
-  newysd := newysd / (N - 1);
-  newysd := sqrt(newysd);
-
-  newcorr := newcorr - newxmean * newymean / N;
-  newcorr := newcorr / (N - 1);
-  newcorr := newcorr / (newxsd * newysd);
-
-  newxmean := newxmean / N;
-  newymean := newymean / N;
-  newb :=  newcorr * (newysd / newxsd);
-  newconstant :=  newymean - newb * newxmean;
-
-  lReport := TStringList.Create;
-  try
-    lReport.Add('POPULATION PARAMETERS FOR THE SIMULATION');
-    lReport.Add('');
-    lReport.Add('Mean X:                      %8.3f', [xmean]);
-    lReport.Add('Std. Dev. X:                 %8.3f', [xsd]);
-    lReport.Add('');
-    lReport.Add('Mean Y:                      %8.3f', [ymean]);
-    lReport.Add('Std. Dev. Y:                 %8.3f', [ysd]);
-    lReport.Add('');
-    lReport.Add('Product-Moment Correlation:  %8.3f', [corxy]);
-    lReport.Add('Regression line slope:       %8.3f', [b]);
-    lReport.Add('                constant:    %8.3f', [constant]);
-    lReport.Add('');
-    lReport.Add(DIVIDER);
-    lReport.Add('');
-    lReport.Add('SAMPLE STATISTICS FOR %d OBSERVATIONS FROM THE POPULATION', [N]);
-    lReport.Add('');
-    lReport.Add('Mean X:                      %8.3f', [newxmean]);
-    lReport.Add('Std. Dev. X:                 %8.3f', [newxsd]);
-    lReport.Add('');
-    lReport.Add('Mean Y:                      %8.3f', [newymean]);
-    lReport.Add('Std. Dev. Y:                 %8.3f', [newysd]);
-    lReport.Add('');
-    lReport.Add('Product-Moment Correlation:  %8.3f', [newcorr]);
-    lReport.Add('Regression line slope:       %8.3f', [newb]);
-    lReport.Add('                constant:    %8.3f', [newconstant]);
-    lReport.Add('');
-    lReport.Add(DIVIDER);
-    lReport.Add('');
-    lReport.Add('Pair No.      X          Y     ');
-    lReport.Add('--------  ---------  ---------');
-    for i := 1 to N do
-      lReport.Add('  %4d    %8.3f   %8.3f', [i, x[i], y[i]]);
-
-    DisplayReport(lReport);
-
-    Plot();
-
-  finally
-    lReport.Free;
-    freqx := nil;
-    freqy := nil;
-    x := nil;
-    y := nil;
   end;
 end;
 
-procedure TCorSimFrm.FormShow(Sender: TObject);
+
+procedure TCorSimForm.NumBinsEditChange(Sender: TObject);
 begin
-  Image1.Canvas.Pen.Color := clBlack;
+  if Assigned(FChartFrame) and Assigned(xValues) and Assigned(yValues) then
-  Image1.Canvas.Brush.Color := clWhite;
+    Plot;
-  Image1.Canvas.Rectangle(0, 0, Image1.Width, Image1.Height);
-
-  MeanX.Text := '100';
-  MeanY.Text := '100';
-  SDX.Text := '15';
-  SDY.Text := '15';
-  Corr.Text := '.8';
-  Nobs.Text := '100';
 end;
 
-procedure TCorSimFrm.MeanYKeyPress(Sender: TObject; var Key: char);
-begin
-  if Key = #13 then SDX.SetFocus;
-end;
 
-procedure TCorSimFrm.NobsKeyPress(Sender: TObject; var Key: char);
+procedure TCorSimForm.Plot;
-begin
-  if Key = #13 then ComputeBtn.SetFocus;
-end;
-
-procedure TCorSimFrm.SDXKeyPress(Sender: TObject; var Key: char);
-begin
-  if Key = #13 then SDY.SetFocus;
-end;
-
-procedure TCorSimFrm.SDYKeyPress(Sender: TObject; var Key: char);
-begin
-  if Key = #13 then Corr.SetFocus;
-end;
-
-procedure TCorSimFrm.Plot;
 var
-  minx, maxx, miny, maxy, xincrement, yincrement: double;
+  freqData: DblDyneVec;
-  predy1, predy2, lowerx, upperx, frange, prop: double;
+  x, mn, mx: Double;
-  charlabel: string;
+  i, n: Integer;
-  xpos, ypos, xpos1, ypos1, xpos2, ypos2: integer;
+  xpts, ypts: DblDyneVec;
-  i, winwidth, winheight, xoffset, yoffset, xaxislong, yaxislong: integer;
-  j, xspacing, yspacing, labelwidth, minfreq, maxfreq: integer;
-  flength, theight, lowery, uppery: integer;
 begin
-  // get min and max of x and y points
+  FChartFrame.Clear;
-  minx :=  x[1];
+  XHistogramSeries.Clear;
-  maxx :=  minx;
+  YHistogramSeries.Clear;
-  miny :=  y[1];
+
-  maxy :=  miny;
+  // Chart labelling
-  for i := 1 to N do
+  FChartFrame.SetXTitle('x distribution');
+  FChartFrame.SetYTitle('y distribution');
+  FChartFrame.SetFooter(Format(
+    'Correlation: %.3f' + LineEnding +
+    'X Mean: %.3f, StdDev: %.3f' + LineEnding +
+    'Y Mean: %.3f, StdDev: %.3f', [
+    SimResult.CorrXY, SimResult.XMean, SimResult.XStdDev, SimResult.YMean, SimResult.YStdDev
+  ]));
+  FChartFrame.Chart.Legend.Alignment := laBottomCenter;
+  FChartFrame.Chart.Legend.ColumnCount := 2;
+
+  // Draw data points
+  FChartFrame.PlotXY(ptSymbols, xValues, yValues, nil, nil, 'Data', DATA_COLORS[0]);
+
+  // Draw top histogram
+  VecMaxMin(xValues, mx, mn);
+  n := NumBinsEdit.Value;
+  freqData := VecHistogram(xValues, mn, mx, n);
+  for i:= 0 to n-1 do
   begin
-    if (minx > x[i]) then minx :=  x[i];
+    x := i / (n-1) * (mx - mn) + mn;
-    if (maxx < x[i]) then maxx :=  x[i];
+    XHistogramSeries.AddXY(x, freqData[i]);
-    if (miny > y[i]) then miny :=  y[i];
-    if (maxy < y[i]) then maxy :=  y[i];
-  end;
-  xincrement :=  (maxx - minx) / 10;
-  yincrement :=  (maxy - miny) / 10;
-
-  winwidth :=  Image1.Width;
-  winheight :=  Image1.Height;
-  xoffset := winwidth div 5;
-  yoffset := winheight div 5;
-  xaxislong :=  winwidth - xoffset- winwidth div 10;
-  yaxislong :=  winheight - yoffset - winheight div 10;
-  xspacing := xaxislong div 10;
-  yspacing := yaxislong div 10;
-
-  Image1.Canvas.Pen.Color :=  clBlack;
-  Image1.Canvas.Line(xoffset, yaxislong, winwidth, yaxislong);
-  Image1.canvas.Line(xoffset, yaxislong, xoffset, 0);
-
-  // do xaxis
-  for i := 0 to 11 do
-  begin
-    Image1.Canvas.Line(xoffset + i * xspacing, yaxislong, xoffset + i * xspacing, yaxislong + 10);
-    charlabel := Format('%.3f', [minx + i * xincrement]);
-    labelwidth :=  Image1.Canvas.TextWidth(charlabel);
-    xpos :=  xoffset + i * xspacing - labelwidth div 2;
-    ypos :=  yaxislong + 12;
-    Image1.Canvas.TextOut(xpos, ypos, charlabel);
   end;
 
-  // do yaxis
+  // Draw regression line
-  for i := 0 to 11 do
+  // Regression line
-  begin
+  SetLength(xpts, 2);
-    Image1.Canvas.Line(xoffset, yaxislong - i * yspacing, xoffset-10, yaxislong - i * yspacing);
+  SetLength(yPts, 2);
-    charlabel := Format('%.3f', [miny + i * yincrement]);
+  xpts[0] := mn;   ypts[0] := SimResult.a + SimResult.b * xpts[0];
-    labelwidth :=  Image1.Canvas.TextWidth(charlabel);
+  xpts[1] := mx;   ypts[1] := SimResult.a + SimResult.b * xpts[1];
-    xpos :=  xoffset - 10 - labelwidth;
+  FChartFrame.PlotXY(ptLines, xpts, ypts, nil, nil, 'Regression line', clBlack);
-    ypos :=  yaxislong - i * yspacing;
-    Image1.Canvas.TextOut(xpos, ypos, charlabel);
-  end;
 
-  // plot points
+  // Draw right histogram
-  Image1.Canvas.Pen.Color :=  clRed;
+  VecMaxMin(yValues, mx, mn);
-  for i := 1 to N do
+  n := NumBinsEdit.Value;
+  freqData := VecHistogram(yValues, mn, mx, n);
+  for i := 0 to n-1 do
   begin
-    xpos :=  round(xoffset + ((x[i] - minx) / (maxx - minx) * xaxislong));
+    x := i / (n-1) * (mx - mn) + mn;
-    ypos :=  round(yaxislong - ((y[i] - miny) / (maxy - miny) * yaxislong));
+    YHistogramSeries.AddXY(x, freqData[i]);
-    Image1.Canvas.Ellipse(xpos, ypos, xpos+5, ypos+5);
-  end;
-
-  // draw regression line
-  Image1.Canvas.Pen.Color :=  clBlack;
-  predy1 :=  newb * minx + newconstant;
-  predy2 :=  newb * maxx + newconstant;
-  xpos1 :=  xoffset;
-  xpos2 :=  xoffset + xaxislong;
-  ypos1 :=  round(yaxislong - ((predy1 - miny) / (maxy - miny) * yaxislong));
-  ypos2 :=  round(yaxislong - ((predy2 - miny) / (maxy - miny) * yaxislong));
-  Image1.Canvas.Line(xpos1, ypos1, xpos2, ypos2);
-
-  // do x frequency distribution
-  xincrement := (maxx - minx) / 50.0;
-  xspacing :=  xaxislong div 50;
-  for j := 1 to 51 do
-    freqx[j] :=  0;
-  for i := 1 to N do
-  begin
-    for j := 1 to 51 do
-    begin
-      lowerx :=  minx + j * xincrement;
-      upperx :=  minx + (j+1) * xincrement;
-      if (x[i] >= lowerx) and (x[i] < upperx) then
-        freqx[j] := freqx[j] + 1;
   end;
 end;
 
-  // plot the x frequencies
-  minfreq :=  N;
-  maxfreq :=  0;
-  for j := 1 to 51 do
-  begin
-    if (freqx[j] > maxfreq) then
-      maxfreq :=  freqx[j];
-    if (freqx[j] < minfreq) then
-      minfreq :=  freqx[j];
-  end;
-  flength :=  winheight - (yaxislong + 25) - Panel1.Height;
-  for j := 1 to 51 do
-  begin
-    xpos :=  xoffset + j * xspacing;
-    ypos1 :=  round(yaxislong + 25 + (freqx[j] - minfreq)/ (maxfreq-minfreq) * flength);
-    ypos2 :=  yaxislong + 25;
-    Image1.Canvas.Line(xpos, ypos1, xpos, ypos2);
-  end;
-  Image1.Canvas.Line(xoffset, yaxislong+25, winwidth, yaxislong+25);
 
-  xpos :=  20;
+procedure TCorSimForm.Reset;
-  ypos :=  yaxislong+30;
-  Image1.Canvas.TextOut(xpos, ypos, 'X DISTRIBUTION');
-
-  theight :=  Image1.Canvas.TextHeight('X');
-  ypos := ypos + theight;
-  charlabel := Format('Correlation: %.3f', [newcorr]);
-  Image1.Canvas.TextOut(xpos, ypos, charlabel);
-  ypos := ypos + theight;
-  charlabel := Format('Mean X: %.3f; Mean Y: %.3f', [newxmean, newymean]);
-  Image1.Canvas.TextOut(xpos, ypos, charlabel);
-  charlabel := Format('SD X: %.3f; SD Y: %.3f', [newxsd, newysd]);
-  ypos := ypos + theight;
-  Image1.Canvas.TextOut(xpos,ypos,charlabel);
-
-  // do y frequency distribution
-  yincrement :=  (maxy-miny) / 50.0;
-  yspacing :=  yaxislong div 50;
-  for j := 1 to 51 do
-    freqy[j] :=  0;
-  for i := 1 to N do
 begin
-    for j := 1 to 51 do
+  inherited;
-    begin
+  MeanXEdit.Text := '100';
-      lowery :=  round(miny + j * yincrement);
+  MeanYEdit.Text := '100';
-      uppery :=  round(miny + ((j+1) * yincrement));
+  StdDevXEdit.Text := '15';
-      if (y[i] >= lowery) and (y[i] < uppery) then
+  StdDevYEdit.Text := '15';
-        freqy[j] := freqy[j] + 1;
+  CorrEdit.Text := '0.8';
-    end;
+  NumObsEdit.Text := '100';
+  NumBinsEdit.Value := 12;
 end;
 
-  // plot the y frequencies
-  minfreq :=  N;
-  maxfreq :=  0;
-  for j := 1 to 51 do
-  begin
-    if (freqy[j] > maxfreq) then maxfreq :=  freqy[j];
-    if (freqy[j] < minfreq) then minfreq :=  freqy[j];
-  end;
-  flength :=  winwidth - (xaxislong + 150);
-  for j := 1 to 51 do
-  begin
-    ypos :=  yaxislong - j * yspacing;
-    frange :=  maxfreq - minfreq;
-    prop :=  (freqy[j] - minfreq) / frange;
-    xpos1 :=  round(xoffset - 50 - prop * flength);
-    xpos2 :=  xoffset - 50;
-    Image1.Canvas.Line(xpos1, ypos, xpos2, ypos);
-  end;
-  Image1.Canvas.Line(xoffset - 50, yaxislong, xoffset - 50, 0);
-  Image1.Canvas.TextOut(0,0,'Y DISTRIBUTION');
-end;
 
-function TCorSimFrm.Validate(out AMsg: String; out AControl: TWinControl): Boolean;
+function TCorSimForm.Validate(out AMsg: String; out AControl: TWinControl): Boolean;
+var
+  x: Double;
+  n: Integer;
 begin
   Result := false;
 
-  if (MeanX.Text = '') or (MeanY.Text = '') or
+  if (MeanXEdit.Text = '') or (MeanYEdit.Text = '') or
-     (SDX.Text = '') or (SDY.Text = '') or
+     (StdDevXEdit.Text = '') or (StdDevYEdit.Text = '') or
-     (Corr.Text = '') or (NObs.Text = '') then
+     (CorrEdit.Text = '') or (NumObsEdit.Text = '') then
   begin
-    if MeanX.Text = '' then
+    if MeanXEdit.Text = '' then
-      AControl := MeanX
+      AControl := MeanXEdit
-    else if MeanY.Text = '' then
+    else if MeanYEdit.Text = '' then
-      AControl := MeanY
+      AControl := MeanYEdit
-    else if SDX.Text = '' then
+    else if StdDevXEdit.Text = '' then
-      AControl := SDX
+      AControl := StdDevXEdit
-    else if SDY.Text = '' then
+    else if StdDevYEdit.Text = '' then
-      AControl := SDY
+      AControl := StdDevYEdit
-    else if Corr.Text = '' then
+    else if CorrEdit.Text = '' then
-      AControl := Corr
+      AControl := CorrEdit
-    else if NObs.Text = '' then
+    else if NumObsEdit.Text = '' then
-      AControl := NObs;
+      AControl := NumObsEdit;
     AMsg := 'Input cannot be empty.';
     exit;
   end;
 
-  if not TryStrToFloat(MeanX.Text, xMean) then
+  if not TryStrToFloat(MeanXEdit.Text, x) then
   begin
-    AControl := MeanX;
+    AControl := MeanXEdit;
     AMsg := 'Mean X must be a valid number.';
     exit;
   end;
 
-  if not TryStrToFloat(MeanY.Text, yMean) then
+  if not TryStrToFloat(MeanYEdit.Text, x) then
   begin
-    AControl := MeanY;
+    AControl := MeanYEdit;
     AMsg := 'Mean Y must be a valid number.';
     exit;
   end;
 
-  if not TryStrToFloat(SDX.Text, xSD) or (xSD <= 0) then
+  if not TryStrToFloat(StdDevXEdit.Text, x) or (x <= 0) then
   begin
-    AControl := SDX;
+    AControl := StdDevXEdit;
     AMsg := 'Std.Dev X must be a valid positive number.';
     exit;
   end;
 
-  if not TryStrToFloat(SDY.Text, ySD) or (ySD <= 0) then
+  if not TryStrToFloat(StdDevYEdit.Text, x) or (x <= 0) then
   begin
-    AControl := SDY;
+    AControl := StdDevYEdit;
     AMsg := 'Std.Dev Y must be a valid positive number.';
     exit;
   end;
 
-  if not TryStrToFloat(Corr.Text, corXY) then
+  if not TryStrToFloat(CorrEdit.Text, x) then
   begin
-    AControl := Corr;
+    AControl := CorrEdit;
     AMsg := 'Correlation XY must be a valid number.';
     exit;
   end;
 
-  if not TryStrToInt(NObs.Text, N) or (N <= 0) then
+  if not TryStrToInt(NumObsEdit.Text, n) or (n <= 0) then
   begin
-    AControl := NObs;
+    AControl := NumObsEdit;
     AMsg := 'Number of observations must be a valid positive integer.';
     exit;
   end;
 
+  if NumBinsEdit.Text = '' then
+  begin
+    AControl := NumBinsEdit;
+    AMsg := 'Empty input not allowed here.';
+    exit;
+  end;
+
+  if not TryStrToInt(NumBinsEdit.Text, n) or (n < 2) then
+  begin
+    AControl := NumBinsEdit;
+    AMsg := 'There must be at least 2 bins.';
+    exit;
+  end;
+
   Result := true;
 end;
 
-initialization
+
-  {$I corsimunit.lrs}
+procedure TCorSimForm.WriteReport(
+  A, B, XMean, YMean, XStdDev, YStdDev, CorrXY: Double);
+var
+  lReport: TStrings;
+  i: Integer;
+begin
+  lReport := TStringList.Create;
+  try
+    lReport.Add('POPULATION PARAMETERS FOR THE SIMULATION');
+    lReport.Add('');
+    lReport.Add('Mean X:                      %8.3f', [XMean]);
+    lReport.Add('Std. Dev. X:                 %8.3f', [XStdDev]);
+    lReport.Add('');
+    lReport.Add('Mean Y:                      %8.3f', [YMean]);
+    lReport.Add('Std. Dev. Y:                 %8.3f', [YStdDev]);
+    lReport.Add('');
+    lReport.Add('Product-Moment Correlation:  %8.3f', [CorrXY]);
+    lReport.Add('Regression line slope:       %8.3f', [B]);
+    lReport.Add('                constant:    %8.3f', [A]);
+    lReport.Add('');
+    lReport.Add(DIVIDER);
+    lReport.Add('');
+    lReport.Add('SAMPLE STATISTICS FOR %d OBSERVATIONS FROM THE POPULATION', [Length(xValues)]);
+    lReport.Add('');
+    lReport.Add('Mean X:                      %8.3f', [SimResult.XMean]);
+    lReport.Add('Std. Dev. X:                 %8.3f', [SimResult.XStdDev]);
+    lReport.Add('');
+    lReport.Add('Mean Y:                      %8.3f', [SimResult.YMean]);
+    lReport.Add('Std. Dev. Y:                 %8.3f', [SimResult.YStdDev]);
+    lReport.Add('');
+    lReport.Add('Product-Moment Correlation:  %8.3f', [SimResult.CorrXY]);
+    lReport.Add('Regression line slope:       %8.3f', [SimResult.B]);
+    lReport.Add('                constant:    %8.3f', [SimResult.A]);
+    lReport.Add('');
+    lReport.Add(DIVIDER);
+    lReport.Add('');
+    lReport.Add('Pair No.      X          Y     ');
+    lReport.Add('--------  ---------  ---------');
+    for i := 0 to High(XValues) do
+      lReport.Add('  %4d    %8.3f   %8.3f', [i, xValues[i], yValues[i]]);
+
+    FReportFrame.DisplayReport(lReport);
+
+  finally
+    lReport.Free;
+  end;
+end;
+
 
 end.
 

applications/lazstats/source/units/matrixunit.pas

@@ -42,19 +42,24 @@ procedure VecMeanVarStdDevSS(const AData: TDblVector;
 procedure VecSumSS(const AData: TDblVector;
   out Sum, SS: Double);
 
+function VecHistogram(const AData: TDblVector; AMin, AMax: Double;
+  N: Integer): TDblVector;
+
 function VecMedian(const AData: TDblVector): Double;
 
+
 // Matrices
 
+{ NOTE: Indices follow math convention:
+  - 1st index is the row index, i.e. runs vertically
+  - 2nd index is the col index, i.e. runs horizontally
+  All indices are 0-based. }
+
 operator + (A, B: TDblMatrix): TDblMatrix;
 operator - (A, B: TDblMatrix): TDblMatrix;
 operator * (A, B: TDblMatrix): TDblMatrix;
 operator * (A: TDblMatrix; v: TDblVector): TDblVector;
 
-{ NOTE: Indices follow math convention:
-  - 1st index is the row index, i.e. runs vertically
-  - 2nd index is the col index, i.e. runs horizontally
-  All indices are 0-based. }
 function MatAppendColVector(A: TDblMatrix; v: TDblVector): TDblMatrix;
 procedure MatCheck(A: TDblMatrix);
 procedure MatCheckSquare(A: TDblMatrix; out n: Integer);
@@ -319,6 +324,26 @@ begin
 end;
 
 
+function VecHistogram(const AData: TDblVector; AMin, AMax: Double;
+  N: Integer): TDblVector;
+var
+  i, j: Integer;
+  factor: Double;
+begin
+  SetLength(Result, N);
+  for j := 0 to N-1 do Result[j] := 0;
+
+  factor := N / (AMax - AMin);
+  for i := 0 to High(AData) do
+  begin
+    j := trunc((AData[i] - AMin) * factor);
+    if j <= 0 then j := 0;
+    if j >= N then j := N-1;
+    Result[j] := Result[j] + 1;
+  end;
+end;
+
+
 function VecMedian(const AData: TDblVector): Double;
 var
   N, midPt: integer;