unit TwoWayLogLinUnit;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs,
  ExtCtrls, StdCtrls, Buttons, Grids, OutPutUnit, Math, MainUnit, FunctionsLib,
  Globals, DataProcs, contexthelpunit;

type

  { TTwoWayLogLinFrm }

  TTwoWayLogLinFrm = class(TForm)
    HelpBtn: TButton;
    ResetBtn: TButton;
    CancelBtn: TButton;
    ComputeBtn: TButton;
    ReturnBtn: TButton;
    RowInBtn: TBitBtn;
    RowOutBtn: TBitBtn;
    ColInBtn: TBitBtn;
    ColOutBtn: TBitBtn;
    FreqInBtn: TBitBtn;
    FreqOutBtn: TBitBtn;
    NoRowsEdit: TEdit;
    NoColsEdit: TEdit;
    NoRowsLabel: TLabel;
    NoColsLabel: TLabel;
    RowVarEdit: TEdit;
    ColVarEdit: TEdit;
    FreqVarEdit: TEdit;
    FileFromGrp: TRadioGroup;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Grid: TStringGrid;
    VarList: TListBox;
    procedure ColInBtnClick(Sender: TObject);
    procedure ColOutBtnClick(Sender: TObject);
    procedure ComputeBtnClick(Sender: TObject);
    procedure FileFromGrpClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FreqInBtnClick(Sender: TObject);
    procedure FreqOutBtnClick(Sender: TObject);
    procedure HelpBtnClick(Sender: TObject);
    procedure NoColsEditKeyPress(Sender: TObject; var Key: char);
    procedure NoRowsEditKeyPress(Sender: TObject; var Key: char);
    procedure ResetBtnClick(Sender: TObject);
    procedure RowInBtnClick(Sender: TObject);
    procedure RowOutBtnClick(Sender: TObject);

  private
    { private declarations }
    procedure PrintTable(Nrows, Ncols : integer;
                         VAR Data : DblDyneMat;
                         VAR RowMarg : DblDyneVec;
                         VAR ColMarg : DblDyneVec;
                         Total : double);
    procedure Iterate(Nrows, Ncols : integer;
                      VAR Data : DblDyneMat;
                      VAR RowMarg : DblDyneVec;
                      VAR ColMarg : DblDyneVec;
                      VAR Total : double;
                      VAR Expected : DblDyneMat;
                      VAR NewRowMarg : DblDyneVec;
                      VAR NewColMarg : DblDyneVec;
                      VAR NewTotal : double);
    procedure PrintLamdas(Nrows,Ncols : integer;
                          Var CellLambdas : DblDyneCube;
                          mu : double);

  public
    { public declarations }
  end; 

var
  TwoWayLogLinFrm: TTwoWayLogLinFrm;

implementation

{ TTwoWayLogLinFrm }

procedure TTwoWayLogLinFrm.ResetBtnClick(Sender: TObject);
VAR i, j : integer;
begin
     for i := 0 to Grid.RowCount - 1 do
         for j := 0 to Grid.ColCount - 1 do
             Grid.Cells[j,i] := '';
     Grid.ColCount := 3;
     Grid.RowCount := 2;
     Grid.Cells[0,0] := 'ROW';
     Grid.Cells[1,0] := 'COL';
     Grid.Cells[2,0] := 'FREQ';
     VarList.Clear;
     for i := 1 to NoVariables do
         VarList.Items.Add(OS3MainFrm.DataGrid.Cells[i,0]);
     RowVarEdit.Text := '';
     ColVarEdit.Text := '';
     FreqVarEdit.Text := '';
     NoRowsEdit.Text := '';
     NoColsEdit.Text := '';
     VarList.Visible := false;
     RowInBtn.Visible := false;
     RowOutBtn.Visible := false;
     ColInBtn.Visible := false;
     ColOutBtn.Visible := false;
     FreqInBtn.Visible := false;
     FreqOutBtn.Visible := false;
     Label1.Visible := false;
     Label2.Visible := false;
     Label3.Visible := false;
     RowVarEdit.Visible := false;
     ColVarEdit.Visible := false;
     FreqVarEdit.Visible := false;
//     Memo1.Visible := false;
     NoRowsLabel.Visible := false;
     NoColsLabel.Visible := false;
     NoRowsEdit.Visible := false;
     NoColsEdit.Visible := false;
     Grid.Visible := false;
end;

procedure TTwoWayLogLinFrm.RowInBtnClick(Sender: TObject);
VAR index : integer;
begin
     index := VarList.ItemIndex;
     RowVarEdit.Text := VarList.Items.Strings[index];
     VarList.Items.Delete(index);
     RowOutBtn.Visible := true;
     RowInBtn.Visible := false;
end;

procedure TTwoWayLogLinFrm.RowOutBtnClick(Sender: TObject);
begin
     VarList.Items.Add(RowVarEdit.Text);
     RowInBtn.Visible := true;
     RowOutBtn.Visible := false;
     RowVarEdit.Text := '';
end;

procedure TTwoWayLogLinFrm.FormShow(Sender: TObject);
begin
     ResetBtnClick(Self);
end;

procedure TTwoWayLogLinFrm.FreqInBtnClick(Sender: TObject);
VAR index : integer;
begin
     index := VarList.ItemIndex;
     FreqVarEdit.Text := VarList.Items.Strings[index];
     VarList.Items.Delete(index);
     FreqOutBtn.Visible := true;
     FreqInBtn.Visible := false;
end;

procedure TTwoWayLogLinFrm.FreqOutBtnClick(Sender: TObject);
begin
     VarList.Items.Add(FreqVarEdit.Text);
     FreqInBtn.Visible := true;
     FreqOutBtn.Visible := false;
     FreqVarEdit.Text := '';
end;

procedure TTwoWayLogLinFrm.HelpBtnClick(Sender: TObject);
begin
  ContextHelpForm.HelpMessage((Sender as TButton).tag);
end;

procedure TTwoWayLogLinFrm.NoColsEditKeyPress(Sender: TObject; var Key: char);
var
   i, j, row : integer;
   Ncols, Nrows : integer;

begin
     if ord(Key) = 13 then
     begin
          Nrows := StrToInt(NoRowsEdit.Text);
          Ncols := StrToInt(NoColsEdit.Text);
          Grid.RowCount := (Nrows * Ncols) + 1;
          // setup row and column values in the grid
          row := 1;
          for j := 1 to Ncols do
          begin
               for i := 1 to Nrows do
               begin
                    Grid.Cells[0,row] := IntToStr(i);
                    Grid.Cells[1,row] := IntToStr(j);
                    row := row + 1;
               end;
          end;
          Grid.SetFocus;
     end;
end;

procedure TTwoWayLogLinFrm.NoRowsEditKeyPress(Sender: TObject; var Key: char);
begin
     if ord(Key) = 13 then NoColsEdit.SetFocus;
end;

procedure TTwoWayLogLinFrm.ComputeBtnClick(Sender: TObject);
var
   Data : DblDyneMat;
   NewData : DblDyneMat;
   Prop : DblDyneMat;
   LogData : DblDyneMat;
   Expected : DblDyneMat;
   i, j, k : integer;
   RowMarg : DblDyneVec;
   NewRowMarg : DblDyneVec;
   RowLogs : DblDyneVec;
   ColMarg : DblDyneVec;
   NewColMarg : DblDyneVec;
   ColLogs : DblDyneVec;
   CellLambdas : DblDyneCube;
   Total : double;
   NewTotal : double;
   TotalLogs : double;
   mu : double;
   row, col : integer;
   ModelTotal : double;
   astr : string;
   Ysqr : double;
   DF : integer;
   chisqr, prob : double;
   odds : double;
   Nrows, Ncols : integer;
   RowCol, ColCol, Fcol : integer;
   GridPos : IntDyneVec;
   value : integer;
   Fx : double;

begin
     Total := 0.0;
     TotalLogs := 0.0;
     Nrows := 0;
     Ncols := 0;

     if FileFromGrp.ItemIndex = 0 then // mainfrm input
     begin
          SetLength(GridPos,3);
          for i := 1 to NoVariables do
          begin
               if RowVarEdit.Text = OS3MainFrm.DataGrid.Cells[i,0] then GridPos[0] := i;
               if ColVarEdit.Text = OS3MainFrm.DataGrid.Cells[i,0] then GridPos[1] := i;
               if FreqVarEdit.Text = OS3MainFrm.DataGrid.Cells[i,0] then GridPos[2] := i;
          end;
          // get no. of rows and columns
          for i := 1 to OS3MainFrm.DataGrid.RowCount - 1 do
          begin
               value := StrToInt(OS3MainFrm.DataGrid.Cells[GridPos[0],i]);
               if value > Nrows then Nrows := value;
               value := StrToInt(OS3MainFrm.DataGrid.Cells[GridPos[1],i]);
               if value > Ncols then Ncols := value;
          end;
          // Get data
          SetLength(Data,Nrows+1,Ncols+1);
          SetLength(CellLambdas,Nrows+1,Ncols+1,4);
          SetLength(RowMarg,Nrows+1);
          SetLength(RowLogs,Nrows+1);
          SetLength(ColMarg,Ncols+1);
          SetLength(ColLogs,Ncols+1);
          SetLength(Prop,Nrows+1,Ncols+1);
          SetLength(LogData,Nrows+1,Ncols+1);
          SetLength(Expected,Nrows+1,Ncols+1);
          SetLength(NewData,Nrows+1,Ncols+1);
          SetLength(NewRowMarg,Nrows+1);
          SetLength(NewColMarg,Ncols+1);

          for i := 1 to Nrows do
              for j := 1 to Ncols do
                  Data[i,j] := 0.0;
          rowcol := GridPos[0];
          colcol := GridPos[1];
          Fcol := GridPos[2];
          for i := 1 to OS3MainFrm.DataGrid.RowCount - 1 do
          begin
               if Not GoodRecord(i, 3, GridPos) then continue;
               row := StrToInt(OS3MainFrm.DataGrid.Cells[rowcol,i]);
               col := StrToInt(OS3MainFrm.DataGrid.Cells[colcol,i]);
               Fx := StrToInt(OS3MainFrm.DataGrid.Cells[Fcol,i]);
               Data[row,col] := Data[row,col] + Fx;
               Total := Total + Fx;
          end;
          GridPos := nil;
     end;

     if FileFromGrp.ItemIndex = 1 then // form data
     begin
          Nrows := StrToInt(NoRowsEdit.Text);
          Ncols := StrToInt(NoColsEdit.Text);
          SetLength(Data,Nrows+1,Ncols+1);
          SetLength(CellLambdas,Nrows+1,Ncols+1,4);
          SetLength(RowMarg,Nrows+1);
          SetLength(RowLogs,Nrows+1);
          SetLength(ColMarg,Ncols+1);
          SetLength(ColLogs,Ncols+1);
          SetLength(Prop,Nrows+1,Ncols+1);
          SetLength(LogData,Nrows+1,Ncols+1);
          SetLength(Expected,Nrows+1,Ncols+1);
          SetLength(NewData,Nrows+1,Ncols+1);
          SetLength(NewRowMarg,Nrows+1);
          SetLength(NewColMarg,Ncols+1);
     end;

     for i := 1 to Nrows do
          for j := 1 to Ncols do
              for k := 1 to 3 do CellLambdas[i,j,k] := 0.0;

     for i := 1 to Nrows do
     begin
          RowMarg[i] := 0.0;
          RowLogs[i] := 0.0;
     end;

     for j := 1 to Ncols do
     begin
          ColMarg[j] := 0.0;
          ColLogs[j] := 0.0;
     end;

     if FileFromGrp.ItemIndex = 1 then // get data from grid
     begin
          for i := 1 to (Nrows * Ncols) do
          begin
               row := StrToInt(Grid.Cells[0,i]);
               col := StrToInt(Grid.Cells[1,i]);
               Data[row,col] := StrToFloat(Grid.Cells[2,i]);
               Total := Total + Data[row,col];
          end;
     end;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowMarg[i] := RowMarg[i] + Data[i,j];
               ColMarg[j] := ColMarg[j] + Data[i,j];
               Prop[i,j] := Prop[i,j] / Total;
               LogData[i,j] := ln(Data[i,j]);
          end;
     end;

     // report cross-products odds and log odds ratios
     OutPutFrm.RichEdit.Clear;
     astr := 'ANALYSES FOR AN I BY J CLASSIFICATION TABLE';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Reference: G.J.G. Upton, The Analysis of Cross-tabulated Data, 1980';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     if (Nrows = 2) and (Ncols = 2) then
     begin
          odds := (Data[1,1] * Data[2,2]) / (Data[1,2] * Data[2,1]);
          astr := format('Cross-Products Odds Ratio = %6.3f',[odds]);
          OutPutFrm.RichEdit.Lines.Add(astr);
          astr := format('Log odds of the cross-products ratio = %6.3f',[ln(odds)]);
          OutPutFrm.RichEdit.Lines.Add(astr);
          OutPutFrm.RichEdit.Lines.Add('');
     end;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowLogs[i] := RowLogs[i] + LogData[i,j];
               ColLogs[j] := ColLogs[j] + LogData[i,j];
               TotalLogs := TotalLogs + LogData[i,j];
          end;
     end;

     for i := 1 to Nrows do RowLogs[i] := RowLogs[i] / Ncols;
     for j := 1 to Ncols do ColLogs[j] := ColLogs[j] / Nrows;
     TotalLogs := TotalLogs / (Nrows * Ncols);
     mu := TotalLogs;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               CellLambdas[i,j,1] := RowLogs[i] - TotalLogs;
               CellLambdas[i,j,2] := ColLogs[j] - TotalLogs;
               CellLambdas[i,j,3] := LogData[i,j] - RowLogs[i]  - ColLogs[j] + TotalLogs;
          end;
     end;

     // Get expected values for saturated model
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               ModelTotal := mu;
               for k := 1 to 3 do
                    ModelTotal := ModelTotal + CellLambdas[i,j,k];
               Expected[i,j] := exp(ModelTotal);
          end;
     end;

     // Get Y square for saturated model
     Ysqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Ysqr := Ysqr + Data[i,j] * (ln(Data[i,j]) - ln(Expected[i,j]));
     Ysqr := 2.0 * Ysqr;

     // write out values for saturated model
     astr := 'Saturated Model Results';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Observed Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,Data,RowMarg,ColMarg,Total);
     astr := 'Log frequencies, row average and column average of log frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,LogData,RowLogs,ColLogs,TotalLogs);
     astr := 'Expected Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,Expected,RowMarg,ColMarg,Total);
     astr := 'Cell Parameters';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintLamdas(Nrows,Ncols,CellLambdas, mu);
     astr := 'Y squared statistic for model fit = ' + format('%6.3f',[Ysqr]);
     astr := astr + ' D.F. = 0';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.ShowModal;
     OutPutFrm.RichEdit.Clear;

     // Do the model of independence
     astr := 'Independent Effects Model Results';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Expected Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     Iterate(Nrows,Ncols,Data,RowMarg,ColMarg,Total,Expected,NewRowMarg,NewColMarg,NewTotal);
     PrintTable(Nrows,Ncols,Expected,NewRowMarg,NewColMarg,NewTotal);
     for i := 1 to Nrows do
          for j := 1 to Ncols do
               LogData[i,j] := ln(Expected[i,j]);
     for i := 1 to Nrows do RowLogs[i] := 0.0;
     for j := 1 to Ncols do ColLogs[j] := 0.0;
     TotalLogs := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowLogs[i] := RowLogs[i] + LogData[i,j];
               ColLogs[j] := ColLogs[j] + LogData[i,j];
               TotalLogs := TotalLogs + LogData[i,j];
          end;
     end;

     for i := 1 to Nrows do RowLogs[i] := RowLogs[i] / Ncols;
     for j := 1 to Ncols do ColLogs[j] := ColLogs[j] / Nrows;
     TotalLogs := TotalLogs / (Nrows * Ncols);
     mu := TotalLogs;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               CellLambdas[i,j,1] := RowLogs[i] - TotalLogs;
               CellLambdas[i,j,2] := ColLogs[j] - TotalLogs;
               CellLambdas[i,j,3] := LogData[i,j] - RowLogs[i]  - ColLogs[j] + TotalLogs;
          end;
     end;
     astr := 'Cell Parameters';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintLamdas(Nrows,Ncols,CellLambdas,mu);
     Ysqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Ysqr := Ysqr + Data[i,j] * (ln(Data[i,j]) - ln(Expected[i,j]));
     Ysqr := 2.0 * Ysqr;
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Y squared statistic for model fit = ' + format('%6.3f',[Ysqr]);
     DF := (NRows - 1) * (NCols - 1);
     astr := astr + ' D.F. = ' + IntToStr(DF);
     OutPutFrm.RichEdit.Lines.Add(astr);
     chisqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             chisqr := chisqr + (power((Data[i,j] - Expected[i,j]),2) / Expected[i,j]);
     astr := format('Chi-squared = %6.3f with %d D.F.',[chisqr,DF]);
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.ShowModal;
     OutPutFrm.RichEdit.Clear;

     // Do no Column Effects model
     astr := 'No Column Effects Model Results';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Expected[i,j] := RowMarg[i] / Ncols;
     for i := 1 to Nrows do NewRowMarg[i] := 0.0;
     for j := 1 to Ncols do NewColMarg[j] := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               NewRowMarg[i] := NewRowMarg[i] + Expected[i,j];
               NewColMarg[j] := NewColMarg[j] + Expected[i,j];
          end;
     end;
     astr := 'Expected Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,Expected,NewRowMarg,NewColMarg,NewTotal);
     for i := 1 to Nrows do
          for j := 1 to Ncols do
               LogData[i,j] := ln(Expected[i,j]);
     for i := 1 to Nrows do RowLogs[i] := 0.0;
     for j := 1 to Ncols do ColLogs[j] := 0.0;
     TotalLogs := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowLogs[i] := RowLogs[i] + LogData[i,j];
               ColLogs[j] := ColLogs[j] + LogData[i,j];
               TotalLogs := TotalLogs + LogData[i,j];
          end;
     end;

     for i := 1 to Nrows do RowLogs[i] := RowLogs[i] / Ncols;
     for j := 1 to Ncols do ColLogs[j] := ColLogs[j] / Nrows;
     TotalLogs := TotalLogs / (Nrows * Ncols);
     mu := TotalLogs;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               CellLambdas[i,j,1] := RowLogs[i] - TotalLogs;
               CellLambdas[i,j,2] := ColLogs[j] - TotalLogs;
               CellLambdas[i,j,3] := LogData[i,j] - RowLogs[i]  - ColLogs[j] + TotalLogs;
          end;
     end;
     astr := 'Cell Parameters';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintLamdas(Nrows,Ncols,CellLambdas,mu);
     Ysqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Ysqr := Ysqr + Data[i,j] * (ln(Data[i,j]) - ln(Expected[i,j]));
     Ysqr := 2.0 * Ysqr;
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Y squared statistic for model fit = ' + format('%6.3f',[Ysqr]);
     DF := (Nrows - 1) * Ncols;
     astr := astr + ' D.F. = ' + IntToStr(DF);
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.ShowModal;
     OutPutFrm.RichEdit.Clear;

     // Do no Row Effects model
     astr := 'No Row Effects Model Results';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Expected[i,j] := ColMarg[j] / Nrows;
     for i := 1 to Nrows do  NewRowMarg[i] := 0.0;
     for j := 1 to Ncols do  NewColMarg[j] := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               NewRowMarg[i] := NewRowMarg[i] + Expected[i,j];
               NewColMarg[j] := NewColMarg[j] + Expected[i,j];
          end;
     end;
     astr := 'Expected Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,Expected,NewRowMarg,NewColMarg,NewTotal);
     for i := 1 to Nrows do
          for j := 1 to Ncols do
               LogData[i,j] := ln(Expected[i,j]);
     for i := 1 to Nrows do RowLogs[i] := 0.0;
     for j := 1 to Ncols do ColLogs[j] := 0.0;
     TotalLogs := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowLogs[i] := RowLogs[i] + LogData[i,j];
               ColLogs[j] := ColLogs[j] + LogData[i,j];
               TotalLogs := TotalLogs + LogData[i,j];
          end;
     end;

     for i := 1 to Nrows do RowLogs[i] := RowLogs[i] / Ncols;
     for j := 1 to Ncols do ColLogs[j] := ColLogs[j] / Nrows;
     TotalLogs := TotalLogs / (Nrows * Ncols);
     mu := TotalLogs;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               CellLambdas[i,j,1] := RowLogs[i] - TotalLogs;
               CellLambdas[i,j,2] := ColLogs[j] - TotalLogs;
               CellLambdas[i,j,3] := LogData[i,j] - RowLogs[i]  - ColLogs[j] + TotalLogs;
          end;
     end;
     astr := 'Cell Parameters';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintLamdas(Nrows,Ncols,CellLambdas,mu);
     Ysqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Ysqr := Ysqr + Data[i,j] * (ln(Data[i,j]) - ln(Expected[i,j]));
     Ysqr := 2.0 * Ysqr;
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Y squared statistic for model fit = ' + format('%6.3f',[Ysqr]);
     DF := (Ncols - 1) * Nrows;
     astr := astr + ' D.F. = ' + IntToStr(DF);
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.ShowModal;
     OutPutFrm.RichEdit.Clear;

     // Do equiprobability model
     astr := 'Equiprobability Effects Model Results';
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Expected[i,j] := Total / (Nrows * Ncols);
     for i := 1 to Nrows do NewRowMarg[i] := Total / (Nrows * Ncols);
     for j := 1 to 2 do NewColMarg[j] := Total / (Nrows * Ncols);
     astr := 'Expected Frequencies';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintTable(Nrows,Ncols,Expected,NewRowMarg,NewColMarg,NewTotal);
     for i := 1 to Nrows do
          for j := 1 to Ncols do
               LogData[i,j] := ln(Expected[i,j]);
     for i := 1 to Nrows do RowLogs[i] := 0.0;
     for j := 1 to Ncols do ColLogs[j] := 0.0;
     TotalLogs := 0.0;
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               RowLogs[i] := RowLogs[i] + LogData[i,j];
               ColLogs[j] := ColLogs[j] + LogData[i,j];
               TotalLogs := TotalLogs + LogData[i,j];
          end;
     end;

     for i := 1 to Nrows do RowLogs[i] := RowLogs[i] / Ncols;
     for j := 1 to Ncols do ColLogs[j] := ColLogs[j] / Nrows;
     TotalLogs := TotalLogs / (Nrows * Ncols);
     mu := TotalLogs;

     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               CellLambdas[i,j,1] := RowLogs[i] - TotalLogs;
               CellLambdas[i,j,2] := ColLogs[j] - TotalLogs;
               CellLambdas[i,j,3] := LogData[i,j] - RowLogs[i]  - ColLogs[j] + TotalLogs;
          end;
     end;
     astr := 'Cell Parameters';
     OutPutFrm.RichEdit.Lines.Add(astr);
     PrintLamdas(Nrows,Ncols,CellLambdas,mu);
     Ysqr := 0.0;
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             Ysqr := Ysqr + Data[i,j] * (ln(Data[i,j]) - ln(Expected[i,j]));
     Ysqr := 2.0 * Ysqr;
     OutPutFrm.RichEdit.Lines.Add('');
     astr := 'Y squared statistic for model fit = ' + format('%6.3f',[Ysqr]);
     DF := Nrows * Ncols - 1;
     astr := astr + ' D.F. = ' + IntToStr(DF);
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.ShowModal;
     OutPutFrm.RichEdit.Clear;
     NewColMarg := nil;
     NewRowMarg := nil;
     NewData := nil;
     Expected := nil;
     LogData := nil;
     Prop := nil;
     ColLogs := nil;
     ColMarg := nil;
     RowLogs := nil;
     RowMarg := nil;
     CellLambdas := nil;
     Data := nil;
end;

procedure TTwoWayLogLinFrm.FileFromGrpClick(Sender: TObject);
begin
     if FileFromGrp.ItemIndex = 0 then // file from main form
     begin
          VarList.Visible := true;
          RowInBtn.Visible := true;
          RowOutBtn.Visible := false;
          ColInBtn.Visible := true;
          ColOutBtn.Visible := false;
          FreqInBtn.Visible := true;
          FreqOutBtn.Visible := false;
          Label1.Visible := true;
          Label2.Visible := true;
          Label3.Visible := true;
          RowVarEdit.Visible := true;
          ColVarEdit.Visible := true;
          FreqVarEdit.Visible := true;
//          Memo1.Visible := false;
          NoRowsLabel.Visible := false;
          NoColsLabel.Visible := false;
          NoRowsEdit.Visible := false;
          NoColsEdit.Visible := false;
          Grid.Visible := false;
     end;
     if FileFromGrp.ItemIndex = 1 then // data from this form
     begin
          VarList.Visible := false;
          RowInBtn.Visible := false;
          RowOutBtn.Visible := false;
          ColInBtn.Visible := false;
          ColOutBtn.Visible := false;
          FreqInBtn.Visible := false;
          FreqOutBtn.Visible := false;
          Label1.Visible := false;
          Label2.Visible := false;
          Label3.Visible := false;
          RowVarEdit.Visible := false;
          ColVarEdit.Visible := false;
          FreqVarEdit.Visible := false;
//          Memo1.Visible := true;
          NoRowsLabel.Visible := true;
          NoColsLabel.Visible := true;
          NoRowsEdit.Visible := true;
          NoColsEdit.Visible := true;
          Grid.Visible := true;
     end;
end;

procedure TTwoWayLogLinFrm.ColInBtnClick(Sender: TObject);
VAR index : integer;
begin
     index := VarList.ItemIndex;
     ColVarEdit.Text := VarList.Items.Strings[index];
     VarList.Items.Delete(index);
     ColOutBtn.Visible := true;
     ColInBtn.Visible := false;
end;

procedure TTwoWayLogLinFrm.ColOutBtnClick(Sender: TObject);
begin
     VarList.Items.Add(ColVarEdit.Text);
     ColInBtn.Visible := true;
     ColOutBtn.Visible := false;
     ColVarEdit.Text := '';
end;

procedure TTwoWayLogLinFrm.PrintTable(Nrows, Ncols : integer;
                                    VAR Data : DblDyneMat;
                                    VAR RowMarg : DblDyneVec;
                                    VAR ColMarg : DblDyneVec;
                                    Total : double);
var
   astr : string;
   i, j : integer;
begin
     astr := 'ROW/COL   ';
     for j := 1 to Ncols do astr := astr + format('   %3d    ',[j]);
     astr := astr + '  TOTAL';
     OutPutFrm.RichEdit.Lines.Add(astr);
     for i := 1 to Nrows do
     begin
          astr := format('   %3d    ',[i]);
          for j := 1 to Ncols do
               astr := astr + format(' %8.2f ',[Data[i,j]]);
          astr := astr + format(' %8.2f ',[RowMarg[i]]);
          OutPutFrm.RichEdit.Lines.Add(astr);
     end;
     astr := 'TOTAL     ';
     for j := 1 to Ncols do astr := astr + format(' %8.2f ',[ColMarg[j]]);
     astr := astr + format(' %8.2f ',[Total]);
     OutPutFrm.RichEdit.Lines.Add(astr);
     OutPutFrm.RichEdit.Lines.Add('');
end;

procedure TTwoWayLogLinFrm.Iterate(Nrows, Ncols : integer;
                                 VAR Data : DblDyneMat;
                                 VAR RowMarg : DblDyneVec;
                                 VAR ColMarg : DblDyneVec;
                                 VAR Total : double;
                                 VAR Expected : DblDyneMat;
                                 VAR NewRowMarg : DblDyneVec;
                                 VAR NewColMarg : DblDyneVec;
                                 VAR NewTotal : double);

Label Step;
var
   Aprevious : DblDyneMat;
   i, j : integer;
   delta : double;
   difference : double;

begin
     delta := 0.1;
     difference := 0.0;
     SetLength(Aprevious,Nrows+1,Ncols+1);
     // initialize expected values
     for i := 1 to Nrows do
     begin
         for j := 1 to Ncols do
         begin
             expected[i,j] := 1.0;
             Aprevious[i,j] := 1.0;
         end;
     end;

Step:
     // step 1: initialize new row margins and calculate expected value
     for i := 1 to Nrows do
          for j := 1 to Ncols do
              newrowmarg[i] := newrowmarg[i] + expected[i,j];
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             expected[i,j] := (RowMarg[i] / newrowmarg[i]) * expected[i,j];
     // step 2: initialize new col margins and calculate expected values
     for i := 1 to Nrows do
          for j := 1 to Ncols do
               newcolmarg[j] := newcolmarg[j] + expected[i,j];
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             expected[i,j] := (ColMarg[j] / newcolmarg[j]) * expected[i,j];

     // step 3: check for change and quit if smaller than delta
     for i := 1 to Nrows do
         for j := 1 to Ncols do
             if abs(APrevious[i,j]-expected[i,j]) > difference then
                difference := abs(APrevious[i,j]-expected[i,j]);
     if difference < delta then
     begin
          newtotal := 0.0;
          for i := 1 to Nrows do
              for j := 1 to Ncols do
                  newtotal := newtotal + expected[i,j];
          exit;
     end
     else begin
          for i := 1 to Nrows do
              for j := 1 to Ncols do
                  APrevious[i,j] := expected[i,j];
          for i := 1 to Nrows do newrowmarg[i] := 0.0;
          for j := 1 to Ncols do newcolmarg[j] := 0.0;
          difference := 0.0;
          goto step;
     end;
     Aprevious := nil;
end;

procedure TTwoWayLogLinFrm.PrintLamdas(Nrows,Ncols : integer;
                                     Var CellLambdas : DblDyneCube;
                                     mu : double);
var
   i, j, k : integer;
   astr : string;
begin
     astr := 'ROW COL   MU      LAMBDA ROW   LAMBDA COL   LAMBDA ROW x COL';
     OutPutFrm.RichEdit.Lines.Add(astr);
     for i := 1 to Nrows do
     begin
          for j := 1 to Ncols do
          begin
               astr := format('%3d %3d ',[i,j]);
               astr := astr + format('%6.3f    ',[mu]);
               for k := 1 to 3 do
                    astr := astr + format(' %6.3f      ',[CellLambdas[i,j,k]]);
               OutPutFrm.RichEdit.Lines.Add(astr);
          end;
     end;
     OutPutFrm.RichEdit.Lines.Add('');
end;

initialization
  {$I twowayloglinunit.lrs}

end.