// Use file "cansas.laz" for testing

unit PlotXYUnit;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs,
  StdCtrls, ExtCtrls, Buttons, ComCtrls, Grids,
  MainUnit, Globals, MathUnit, BasicStatsReportAndChartFormUnit,
  ReportFrameUnit, ChartFrameUnit;

type

  { TPlotXYForm }

  TPlotXYForm = class(TBasicStatsReportAndChartForm)
    ConfEdit: TEdit;
    Label4: TLabel;
    LineChk: TCheckBox;
    MeansChk: TCheckBox;
    ConfChk: TCheckBox;
    OptionsGroup: TGroupBox;
    YEdit: TEdit;
    Label3: TLabel;
    XEdit: TEdit;
    Label2: TLabel;
    XInBtn: TBitBtn;
    XOutBtn: TBitBtn;
    YInBtn: TBitBtn;
    YOutBtn: TBitBtn;
    Label1: TLabel;
    VarList: TListBox;
    procedure VarListDblClick(Sender: TObject);
    procedure VarListSelectionChange(Sender: TObject; {%H-}User: boolean);
    procedure XInBtnClick(Sender: TObject);
    procedure XOutBtnClick(Sender: TObject);
    procedure YInBtnClick(Sender: TObject);
    procedure YOutBtnClick(Sender: TObject);

  private
    procedure PlotXY(XPoints, YPoints: DblDyneVec;
      const ARegressionResults: TBivariateRegressionResults);

    function PrepareData(ADataGrid: TStringGrid;
      out xCol, ycol: Integer; out XData, YData: DblDyneVec;
      out ColNoSelected: IntDyneVec): Boolean;

    procedure WriteToReport(ARegressionResults: TBivariateRegressionResults);

  protected
    procedure AdjustConstraints; override;
    procedure Compute; override;
    procedure UpdateBtnStates; override;
    function Validate(out AMsg: String; out AControl: TWinControl): Boolean; override;

  public
    constructor Create(AOwner: TComponent); override;
    procedure Reset; override;
  end; 

var
  PlotXYForm: TPlotXYForm;


implementation

{$R *.lfm}

uses
  TAChartUtils, TAChartAxisUtils, TALegend, TASources, TACustomSeries, TASeries,
  GridProcs, Utils;


{ TPlotXYForm }

constructor TPlotXYForm.Create(AOwner: TComponent);
begin
  inherited;

  FChartFrame.Chart.Legend.Alignment := laBottomCenter;
  FChartFrame.Chart.Legend.ColumnCount := 3;
  FChartFrame.Chart.Legend.TextFormat := tfHTML;
  with FChartFrame.Chart.AxisList.Add do
  begin
    Alignment := calRight;
    Marks.Source := TListChartSource.Create(self);
    Marks.Style := smsLabel;
    Grid.Visible := false;
    TickColor := clNone;
  end;
  with FChartFrame.Chart.AxisList.Add do
  begin
    Alignment := calTop;
    Marks.Source := TListChartSource.Create(self);
    Marks.Style := smsLabel;
    Grid.Visible := false;
    TickColor := clNone;
  end;

  PageControl.ActivePage := ChartPage;
end;


procedure TPlotXYForm.AdjustConstraints;
begin
  ParamsPanel.Constraints.MinHeight := OptionsGroup.Top + OptionsGroup.Height +
    OptionsGroup.BorderSpacing.Bottom + ButtonBevel.Height +
    CloseBtn.Height + CloseBtn.BorderSpacing.Top;
  ParamsPanel.Constraints.MinWidth := OptionsGroup.Width * 2 - XInBtn.Width div 2 - XInBtn.BorderSpacing.Left;

  Constraints.MinHeight := ParamsPanel.Constraints.MinHeight + ParamsPanel.BorderSpacing.Around*2;
  Constraints.MinWidth := ParamsPanel.Constraints.MinWidth + 200;
end;


procedure TPlotXYForm.Compute;
var
  xValues: DblDyneVec = nil;
  yValues: DblDyneVec = nil;
  ColNoSelected: IntDyneVec= nil;
  xCol, yCol: Integer;
  confBand: Double;
  regressionRes: TBivariateRegressionResults;
  C: TWinControl;
  msg: String;
begin
  // Validation: Make sure that XEdit and YEdit are not empty
  if not Validate(msg, C) then
  begin
    C.SetFocus;
    ErrorMsg(msg);
    ModalResult := mrNone;
    exit;
  end;

  // Extract data from Grid
  if not PrepareData(OS3MainFrm.DataGrid, xCol, yCol, xValues, yValues, ColNoSelected) then
    exit;

  // Sort on x values
  SortOnX(xValues, yValues);

  // Calculate regression
  confBand := StrToFloat(ConfEdit.Text) / 100.0;
  Calc_BivariateRegression(xValues, yValues, confBand, regressionRes);

  // Print the descriptive statistics to the output frame
  WriteToReport(regressionRes);

  // Plot the values (and optional line and confidence band if elected)
  PlotXY(xValues, yValues, regressionRes);
end;


procedure TPlotXYForm.PlotXY(XPoints, YPoints: DblDyneVec;
  const ARegressionResults: TBivariateRegressionResults);
var
  tmpX: DblDyneVec = nil;
  tmpY: DblDyneVec = nil;
  conf: DblDyneVec = nil;
  ext: TDoubleRect;
  xmin, xmax, ymin, ymax: Double;
  rightLabels: TListChartSource;
  topLabels: TListChartSource;
  ser: TChartSeries;
  i: Integer;
begin
  rightLabels := FChartFrame.Chart.AxisList[2].Marks.Source as TListChartSource;
  rightLabels.Clear;
  topLabels := FChartFrame.Chart.AxisList[3].Marks.Source as TListChartSource;
  topLabels.Clear;
  FChartFrame.Clear;

  // Titles
  FChartFrame.SetTitle('X vs. Y plot using file ' + OS3MainFrm.FileNameEdit.Text);
  with ARegressionResults do
    FChartFrame.SetFooter(Format('R(X,Y) = %.3f, Slope = %.3f, Intercept = %.3f', [
      R, Slope, Intercept
    ]));
  FChartFrame.SetXTitle(XEdit.Text);
  FChartFrame.SetYTitle(YEdit.Text);

  // Draw upper confidence band
  if ConfChk.Checked then
  begin
    SetLength(conf, ARegressionResults.Count);
     for i := 0 to High(conf) do
       conf[i] := ARegressionResults.ConfidenceLimits(XPoints[i], true);
    ser := FChartFrame.PlotXY(ptLines, XPoints, conf, nil, nil, 'Upper confidence band', clRed);
    rightLabels.Add(ser.yValue[ser.Count-1], ser.YValue[ser.Count-1], 'UCL');
  end;

  // Plot data points
  FChartFrame.PlotXY(ptSymbols, XPoints, YPoints, nil, nil, 'Data values', clNavy);

  // Draw lower confidence band
  if ConfChk.Checked then
  begin
    SetLength(conf, ARegressionResults.Count);
    for i := 0 to High(conf) do
      conf[i] := ARegressionResults.ConfidenceLimits(XPoints[i], false);
    ser := FChartFrame.PlotXY(ptLines, XPoints, conf, nil, nil, 'Lower confidence band', clRed);
    rightLabels.Add(ser.yValue[ser.Count-1], ser.YValue[ser.Count-1], 'LCL');
  end;

  // Draw means
  if MeansChk.Checked then
    with ARegressionResults do
    begin
      FChartFrame.VertLine(XMean, clGreen, psDashDot, 'Mean ' + XEdit.Text);
      topLabels.Add(XMean, XMean, 'Mean ' + XEdit.Text);
      FChartFrame.HorLine(YMean, clGreen, psDash, 'Mean ' + YEdit.Text);
      rightLabels.Add(YMean, YMean, 'Mean ' + YEdit.Text);
    end;

  // Draw regression line
  if LineChk.Checked then
  begin
    ext := FChartFrame.Chart.GetFullExtent;
    SetLength(tmpX, 2);
    SetLength(tmpY, 2);
    tmpX[0] := ext.a.x;
    tmpX[1] := ext.b.x;
    with ARegressionResults do
    begin
      tmpY[1] := tmpX[1] * Slope + Intercept;
      tmpY[0] := tmpX[0] * Slope + Intercept;
    end;
    ser := FChartFrame.PlotXY(ptLines, tmpX, tmpY, nil, nil, 'Predicted', clBlack);
    rightLabels.Add(tmpY[1], tmpY[1], 'Predicted');
  end;

  FChartFrame.Chart.Legend.Visible := false;
end;


function TPlotXYForm.PrepareData(ADataGrid: TStringGrid;
  out xCol, ycol: Integer; out XData, YData: DblDyneVec;
  out ColNoSelected: IntDyneVec): Boolean;
var
  N: Integer;
begin
  Result := false;

  ColNoSelected := nil;
  XData := nil;
  YData := nil;

  xCol := GetVariableIndex(ADataGrid, XEdit.Text);
  yCol := GetVariableIndex(ADataGrid, YEdit.Text);
  if xCol = -1 then
  begin
    ErrorMsg('X variable not found.');
    exit;
  end;

  if yCol = -1 then
  begin
    ErrorMsg('Y variable not found.');
    exit;
  end;

  SetLength(ColNoSelected, 2);
  ColNoSelected[0] := xCol;
  ColNoSelected[1] := yCol;

  XData := CollectValues(ADataGrid, xCol, colNoSelected);
  YData := CollectValues(ADataGrid, ycol, colNoSelected);
  N := Length(XData);
  if N < 3 then
  begin
    ErrorMsg('At least three data points required.');
    exit;
  end;
  if N <> Length(YData) then
  begin
    ErrorMsg('Equal count of cases required for x and y variables.');
    exit;
  end;

  Result := true;
end;


procedure TPlotXYForm.Reset;
var
  i: integer;
begin
  inherited;

  XEdit.Text := '';
  YEdit.Text := '';
  ConfEdit.Text := FormatFloat('0.0', DEFAULT_CONFIDENCE_LEVEL_PERCENT);

  LineChk.Checked := false;
  MeansChk.Checked := false;
  ConfChk.Checked := false;

  VarList.Items.Clear;
  for i := 1 to NoVariables do
    VarList.Items.Add(OS3MainFrm.DataGrid.Cells[i,0]);

  UpdateBtnStates;
end;


procedure TPlotXYForm.UpdateBtnStates;
begin
  inherited;

  XInBtn.Enabled := (VarList.ItemIndex > -1) and (XEdit.Text = '');
  XoutBtn.Enabled := (XEdit.Text <> '');

  YinBtn.Enabled := (VarList.ItemIndex > -1) and (YEdit.Text = '');
  YoutBtn.Enabled := (YEdit.Text <> '');
end;


function TPlotXYForm.Validate(out AMsg: String; out AControl: TWinControl): Boolean;
begin
  Result := false;

  if XEdit.Text = '' then
  begin
    AMsg := 'No variable selected for X.';
    exit;
  end;

  if YEdit.Text = '' then
  begin
    AControl := YEdit;
    AMsg := 'No variable selected for Y.';
    exit;
  end;

  Result := true;
end;


procedure TPlotXYForm.VarListDblClick(Sender: TObject);
var
  index: integer;
begin
  index := VarList.ItemIndex;
  if index > -1 then
  begin
    if XEdit.Text = '' then
      XEdit.Text := VarList.Items[index]
    else
      YEdit.Text := VarList.Items[index];
    VarList.Items.Delete(index);
    UpdateBtnStates;
  end;
end;


procedure TPlotXYForm.VarListSelectionChange(Sender: TObject; User: boolean);
begin
  UpdateBtnStates;
end;


procedure TPlotXYForm.WriteToReport(ARegressionResults: TBivariateRegressionResults);
var
  lReport: TStrings;
begin
  lReport := TStringList.Create;
  try
    lReport.Add('X vs. Y PLOT');
    lReport.Add('');
    lReport.Add('Data file: %s', [OS3MainFrm.FileNameEdit.Text]);
    lReport.Add('');
    lReport.Add('Variables:');
    lReport.Add('  X: %s', [XEdit.Text]);
    lReport.Add('  Y: %s', [YEdit.Text]);
    lReport.Add('');
    lReport.Add('Variable      Mean    Variance  Std.Dev.');
    lReport.Add('----------  --------  --------  --------');
    with ARegressionResults do
    begin
      lReport.Add('%-10s  %8.2f  %8.2f  %8.2f', [XEdit.Text, XMean, XVariance, XStdDev]);
      lReport.Add('%-10s  %8.2f  %8.2f  %8.2f', [YEdit.Text, YMean, YVariance, YStdDev]);
      lReport.Add('');
      lReport.Add('Regression:');
      lReport.Add('  Correlation:                %8.3f', [R]);
      lReport.Add('  Slope:                      %8.3f', [Slope]);
      lReport.Add('  Intercept:                  %8.3f', [Intercept]);
      lReport.Add('  Standard Error of Estimate: %8.3f', [StdErrorPredicted]);
      lReport.Add('  Number of good cases:       %8d',   [Count]);
    end;

    FReportFrame.DisplayReport(lReport);
  finally
    lReport.Free;
  end;
end;


procedure TPlotXYForm.XInBtnClick(Sender: TObject);
var
  index: integer;
begin
  index := VarList.ItemIndex;
  if (index > -1) and (XEdit.Text = '') then
  begin
    XEdit.Text := VarList.Items[index];
    VarList.Items.Delete(index);
    UpdateBtnStates;
  end;
end;


procedure TPlotXYForm.XOutBtnClick(Sender: TObject);
begin
  if XEdit.Text <> '' then
  begin
    VarList.Items.Add(XEdit.Text);
    XEdit.Text := '';
    UpdateBtnStates;
  end;
end;


procedure TPlotXYForm.YInBtnClick(Sender: TObject);
var
  index: integer;
begin
  index := VarList.ItemIndex;
  if (index > -1) and (YEdit.Text = '') then
  begin
    YEdit.Text := VarList.Items[index];
    VarList.Items.Delete(index);
    UpdateBtnStates;
  end;
end;


procedure TPlotXYForm.YOutBtnClick(Sender: TObject);
begin
  if YEdit.Text <> '' then
  begin
    VarList.Items.Add(YEdit.Text);
    YEdit.Text := '';
    UpdateBtnStates;
  end;
end;


end.