unit TwoPropUnit;

{$mode objfpc}{$H+}

interface

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

type

  { TTwoPropFrm }

  TTwoPropFrm = class(TForm)
    HelpBtn: TButton;
    ResetBtn: TButton;
    CancelBtn: TButton;
    ComputeBtn: TButton;
    ReturnBtn: TButton;
    DepFreq00: TEdit;
    DepFreq10: TEdit;
    DepFreq01: TEdit;
    DepFreq11: TEdit;
    CInterval: TEdit;
    Grp: TEdit;
    GrpLabel: TLabel;
    ConfLabel: TLabel;
    Var2: TEdit;
    SecdVarLabel: TLabel;
    Var1: TEdit;
    IndSize2: TEdit;
    IndSize1: TEdit;
    IndFreq2: TEdit;
    IndFreq1: TEdit;
    Samp1Label: TLabel;
    Samp21Label: TLabel;
    Label11: TLabel;
    FirstVarLabel: TLabel;
    Samp2Label: TLabel;
    Samp1SizeLabel: TLabel;
    Samp2SizeLabel: TLabel;
    DepSamp2Label: TLabel;
    DepSamp1Label: TLabel;
    Samp10Label: TLabel;
    Samp11Label: TLabel;
    Samp20Label: TLabel;
    VarList: TListBox;
    Panel1: TPanel;
    Panel2: TPanel;
    RadioGroup1: TRadioGroup;
    RadioGroup2: TRadioGroup;
    procedure ComputeBtnClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure HelpBtnClick(Sender: TObject);
    procedure RadioGroup1Click(Sender: TObject);
    procedure RadioGroup2Click(Sender: TObject);
    procedure ResetBtnClick(Sender: TObject);
    procedure VarListClick(Sender: TObject);
  private
    { private declarations }
    independent : boolean;
    griddata : boolean;

  public
    { public declarations }
  end; 

var
  TwoPropFrm: TTwoPropFrm;

implementation

{ TTwoPropFrm }

procedure TTwoPropFrm.ResetBtnClick(Sender: TObject);
VAR i : integer;
begin
     RadioGroup1.ItemIndex := 0;
     RadioGroup2.ItemIndex := 0;
     Panel1.Visible := true;
     Panel2.Visible := false;
     VarList.Clear;
     Var1.Text := '';
     Var2.Text := '';
     independent := true;
     griddata := false;
     for i := 1 to NoVariables do
     	VarList.Items.Add(OS3MainFrm.DataGrid.Cells[i,0]);
     GrpLabel.Visible := true;
     Grp.Visible := true;
     Grp.Text := '';
     Var2.Visible := false;
     SecdVarLabel.Visible := false;
     DepSamp1Label.Visible := false;
     DepSamp2Label.Visible := false;
     Samp10Label.Visible := false;
     Samp11Label.Visible := false;
     Samp20Label.Visible := false;
     Samp21Label.Visible := false;
     DepFreq00.Visible := false;
     DepFreq00.Text := '';
     DepFreq01.Visible := false;
     DepFreq01.Text := '';
     DepFreq10.Visible := false;
     DepFreq10.Text := '';
     DepFreq11.Visible := false;
     DepFreq11.Text := '';
     IndFreq1.Text := '';
     IndFreq2.Text := '';
     IndSize1.Text := '';
     IndSize2.Text := '';
end;

procedure TTwoPropFrm.VarListClick(Sender: TObject);
VAR index : integer;
begin
     index := VarList.ItemIndex;
     if not independent then
     begin
          if Var1.Text <> '' then Var2.Text := VarList.Items.Strings[index]
          else Var1.Text := VarList.Items.Strings[index];
     end;
     if independent then
     begin
          if Var1.Text <> '' then Grp.Text := VarList.Items.Strings[index]
          else Var1.Text := VarList.Items.Strings[index];
     end;
end;

procedure TTwoPropFrm.FormShow(Sender: TObject);
begin
     ResetBtnClick(self);
end;

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

procedure TTwoPropFrm.ComputeBtnClick(Sender: TObject);
var
   ConfInt, Prop1, Prop2, Prop3, Prop4, zstatistic, zprobability : double;
   PropDif, stderr, criticalz, UCL, LCL, value1, value2, ztest : double;
   P, Q : double;
   i, j, v1, v2, NoSelected, f1, f2, f3, f4, ncases1, ncases2 : integer;
   min, max, group, AB, AC, CD, BD : integer;
   ColNoSelected : IntDyneVec;
   outline, label1, label2 : string;
   errorstate : boolean;

begin
     // Initialize output form
     OutPutFrm.RichEdit.Clear;
     stderr := 0.0;
     PropDif := 0.0;
     v2 := 0;
     ztest := 0.0;
     Prop1 := 0.0;
     Prop2 := 0.0;
     NoSelected := 0;
     v1 := 0;
     zstatistic := 0.0;
     zprobability := 0.0;
     UCL := 0.0;
     LCL := 0.0;

     OutPutFrm.RichEdit.Lines.Add('COMPARISON OF TWO PROPORTIONS');
     OutPutFrm.RichEdit.Lines.Add('');
//     OutPutFrm.RichEdit.ParaGraph.Alignment := taLeftJustify;
     SetLength(ColNoSelected,NoVariables);

     ConfInt := (100.0 - StrToFloat(CInterval.Text)) / 2.0 ;
     ConfInt := (100.0 - ConfInt) / 100.0; // one tail
     ncases1 := 0;
     ncases2 := 0;
     f1 := 0;
     f2 := 0;
     f3 := 0;
     f4 := 0;
     if independent then Var2.Text := Grp.Text;

     if griddata then // data read from grid
     begin
          for i := 1 to NoVariables do
          begin
               if Var1.Text = OS3MainFrm.DataGrid.Cells[i,0] then
               begin
                    v1 := i;
                    ColNoSelected[0] := i;
                    label1 := Var1.Text;
               end;
               if Var2.Text = OS3MainFrm.DataGrid.Cells[i,0] then
               begin
                    v2 := i;
                    ColNoSelected[1] := i;
                    label2 := Var2.Text;
               end;
          end; // next variable

          if not independent then // correlated data
          begin
               for i := 1 to NoCases do
               begin
                    if not GoodRecord(i,NoSelected,ColNoSelected) then continue;
                    ncases1 := ncases1 + 1;
                    value1 := StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v1,i]));
                    value2 := StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v2,i]));
                    f1 := f1 + round(value1);
                    f2 := f2 + round(value2);
               end; // next case
               f3 := ncases1 - f1;
               f4 := ncases1 - f2;
               AB := f1 + f2;
               AC := f1 + f3;
               CD := f3 + f4;
               BD := f2 + f4;
               Prop1 := BD / ncases1;
               Prop2 := AB / ncases1;
               stderr := sqrt((f1 / ncases1 + f4 / ncases1) / ncases1);
               PropDif := Prop1 - Prop2;
               zstatistic := PropDif / stderr;
               ztest := inversez(ConfInt);
               zprobability := 1.0 - probz(abs(zstatistic));
               UCL := PropDif + stderr * ztest;
               LCL := PropDif - stderr * ztest;
          end; // if not independent

          if independent then
          begin
               min := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v2,1])));
               max := min;
               for i := 2 to NoCases do
               begin
                    if not GoodRecord(i,NoSelected,ColNoSelected) then continue;
                    group := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v2,i])));
                    if group < min then min := group;
                    if group > max then max := group;
               end;
               for i := 1 to NoCases do
               begin
                    if not GoodRecord(i,NoSelected,ColNoSelected) then continue;
                    value1 := StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v1,i]));
                    group := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[v2,i])));
                    if group = min then
                    begin
                         f1 := f1 + round(value1);
                         ncases1 := ncases1 + 1;
                    end
                    else
                    begin
                         f2 := f2 + round(value1);
                         ncases2 := ncases2 + 1;
                    end;
               end; // next case
               Prop1 := f1 / ncases1;
               Prop2 := f2 / ncases2;
               PropDif := Prop1 - Prop2;
               P := (f1 + f2) / (ncases1 + ncases2);
               Q := 1.0 - P;
               stderr := sqrt(P * Q * ((1.0 / ncases1) + (1.0 / ncases2)));
               zstatistic := (Prop1 - Prop2) / stderr;
               zprobability := 1.0 - probz(abs(zstatistic));
               ztest := inversez(ConfInt);
               UCL := PropDif + ztest * stderr;
               LCL := PropDif - ztest * stderr;
          end; // end if independent
     end; // if reading grid data

     if not griddata then // data read from form
     begin
          if not independent then // correlated data
          begin
               f1 := round(StrToFloat(DepFreq00.Text));
               f2 := round(StrToFloat(DepFreq10.Text));
               f3 := round(StrToFloat(DepFreq01.Text));
               f4 := round(StrToFloat(DepFreq11.Text));
               ncases1 := f1 + f2 + f3 + f4;
               AB := f1 + f2;
               AC := f1 + f3;
               CD := f3 + f4;
               BD := f2 + f4;
               Prop1 := BD / ncases1;
               Prop2 := AB / ncases1;
               stderr := sqrt((f1 / ncases1 + f4 / ncases1) / ncases1);
               PropDif := Prop1 - Prop2;
               zstatistic := PropDif / stderr;
               ztest := inversez(ConfInt);
               zprobability := 1.0 - probz(abs(zstatistic));
               UCL := PropDif + stderr * ztest;
               LCL := PropDif - stderr * ztest;
          end; // if not independent

          if independent then // independent data
          begin
               f1 := StrToInt(IndFreq1.Text);
               f2 := StrToInt(IndFreq2.Text);
               ncases1 := StrToInt(IndSize1.Text);
               ncases2 := StrToInt(IndSize2.Text);
               Prop1 := f1 / ncases1;
               Prop2 := f2 / ncases2;
               PropDif := Prop1 - Prop2;
               P := (f1 + f2) / (ncases1 + ncases2);
               Q := 1.0 - P;
               stderr := sqrt(P * Q * ((1.0 / ncases1) + (1.0 / ncases2)));
               zstatistic := (Prop1 - Prop2) / stderr;
               zprobability := 1.0 - probz(abs(zstatistic));
               ztest := inversez(ConfInt);
               UCL := PropDif + ztest * stderr;
               LCL := PropDif - ztest * stderr;
          end;
     end;

     // Print the results
     if not independent then
     begin
          OutPutFrm.RichEdit.Lines.Add('Test for Difference Between Two Dependent Proportions');
          OutPutFrm.RichEdit.Lines.Add('');
          OutPutFrm.RichEdit.Lines.Add('Entered Values');
          OutPutFrm.RichEdit.Lines.Add('');
          OutPutFrm.RichEdit.Lines.Add('Sample               1');
          OutPutFrm.RichEdit.Lines.Add('                 0      1    sum');
          OutPutFrm.RichEdit.Lines.Add('           -----------------------');
          outline := format('       0  |%5d   %5d   %5d |',[f1,f2,AB]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          OutPutFrm.RichEdit.Lines.Add('  2        --------|-------|------');
          outline := format('       1  |%5d   %5d   %5d |',[f3,f4,CD]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          OutPutFrm.RichEdit.Lines.Add('           --------|-------|------');
          outline := format(' sum      | %5d  %5d   %5d |',[AC,BD,ncases1]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          OutPutFrm.RichEdit.Lines.Add('');
          outline := format('Confidence Level selected = %s',[CInterval.Text]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Proportion 1 = %9.3f and Proportion 2 = %9.3f with %d cases',
               [Prop1, Prop2, ncases1]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Difference in proportions = %9.3f',[PropDif]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Standard Error of Difference = %9.3f',[stderr]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('z test statistic = %9.3f with probability = %6.4f',
              [zstatistic,zprobability]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('z value for confidence interval = %6.3f',[ztest]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Confidence Interval: (%9.3f,%9.3f)',[LCL,UCL]);
          OutPutFrm.RichEdit.Lines.Add(outline);
     end;
     if independent then
     begin
          OutPutFrm.RichEdit.Lines.Add('Test for Difference Between Two Independent Proportions');
          OutPutFrm.RichEdit.Lines.Add('');
          OutPutFrm.RichEdit.Lines.Add('Entered Values');
          OutPutFrm.RichEdit.Lines.Add('');
          outline := format('Sample 1: Frequency = %5d for %5d cases.',
               [f1, ncases1]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Sample 2: Frequency = %5d for %5d cases.',
              [f2, ncases2]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Proportion 1 = %9.3f, Proportion 2 = %9.3f, Difference = %9.3f',
              [Prop1, Prop2, PropDif]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Standard Error of Difference = %9.3f',[stderr]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Confidence Level selected = %s',[CInterval.Text]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('z test statistic = %9.3f with probability = %6.4f',
              [zstatistic,zprobability]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('z value for confidence interval = %6.3f',[ztest]);
          OutPutFrm.RichEdit.Lines.Add(outline);
          outline := format('Confidence Interval: (%9.3f,%9.3f)',[LCL,UCL]);
          OutPutFrm.RichEdit.Lines.Add(outline);
     end;
     OutPutFrm.ShowModal;
     ColNoSelected := nil;
end;

procedure TTwoPropFrm.RadioGroup2Click(Sender: TObject);
VAR index : integer;
begin
     index := RadioGroup2.ItemIndex;
     if index = 0 then
     begin
          independent := true;
          DepFreq00.Visible := false;
          DepFreq01.Visible := false;
          DepFreq10.Visible := false;
          DepFreq11.Visible := false;
          Samp11Label.Visible := false;
          Samp10Label.Visible := false;
          Samp20Label.Visible := false;
          Samp21Label.Visible := false;
          DepSamp1Label.Visible := false;
          DepSamp2Label.Visible := false;
          IndFreq1.Visible := true;
          IndFreq2.Visible := true;
          IndSize1.Visible := true;
          IndSize2.Visible := true;
          Samp1Label.Visible := true;
          Samp2Label.Visible := true;
          Samp1SizeLabel.Visible := true;
          Samp2SizeLabel.Visible := true;
          FirstVarLabel.Visible := true;
          SecdVarLabel.Visible := false;
          GrpLabel.Visible := true;
          Var1.Visible := true;
          Var2.Visible := false;
          Grp.Visible := true;
     end
     else
     begin
          independent := false;
          DepFreq00.Visible := true;
          DepFreq01.Visible := true;
          DepFreq10.Visible := true;
          DepFreq11.Visible := true;
          DepSamp1Label.Visible := true;
          DepSamp2Label.Visible := true;
          Samp11Label.Visible := true;
          Samp10Label.Visible := true;
          Samp20Label.Visible := true;
          Samp21Label.Visible := true;
          DepSamp1Label.Visible := true;
          DepSamp2Label.Visible := true;
          IndFreq1.Visible := false;
          IndFreq2.Visible := false;
          IndSize1.Visible := false;
          IndSize2.Visible := false;
          Samp1Label.Visible := false;
          Samp2Label.Visible := false;
          Samp1SizeLabel.Visible := false;
          Samp2SizeLabel.Visible := false;
          FirstVarLabel.Visible := true;
          SecdVarLabel.Visible := true;
          GrpLabel.Visible := false;
          Var1.Visible := true;
          Var2.Visible := true;
          Grp.Visible := false;
     end;
end;

procedure TTwoPropFrm.RadioGroup1Click(Sender: TObject);
VAR index : integer;
begin
     index := RadioGroup2.ItemIndex;
     if index = 0 then // independent data
     begin
          independent := true;
     end
     else  // dependent data
     begin
          independent := false;
     end;

     if RadioGroup1.ItemIndex = 0 then  // form data
     begin
          Panel2.Visible := false;
          Panel1.Visible := true;
          griddata := false;
     end
     else  // grid data
     begin
          Panel1.Visible := false;
          Panel2.Visible := true;
          griddata := true;
     end;
end;

initialization
  {$I twopropunit.lrs}

end.