LazStats: Refactor GenKappaUnit. Add pdf help to chm. Add files GenKappa.laz and KappaTest3.laz from OpenStat sample files.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7410 8e941d3f-bd1b-0410-a28a-d453659cc2b4

applications/lazstats/data/KappaTest3.laz

@@ -0,0 +1,107 @@
+20
+3
+Rater
+VARIABLE 1
+1
+I
+0
+99999
+L
+Object
+VARIABLE 2
+1
+I
+0
+99999
+L
+Category
+VARIABLE 3
+1
+I
+0
+99999
+L
+Case 0
+Rater
+Object
+Category
+Case 1
+1
+1
+1
+Case 2
+1
+1
+1
+Case 3
+1
+1
+1
+Case 4
+1
+1
+1
+Case 5
+1
+1
+1
+Case 6
+1
+1
+2
+Case 7
+1
+1
+2
+Case 8
+1
+1
+2
+Case 9
+1
+1
+3
+Case 10
+1
+1
+3
+Case 11
+2
+1
+1
+Case 12
+2
+1
+1
+Case 13
+2
+1
+1
+Case 14
+2
+1
+1
+Case 15
+2
+1
+1
+Case 16
+2
+1
+1
+Case 17
+2
+1
+2
+Case 18
+2
+1
+2
+Case 19
+2
+1
+2
+Case 20
+2
+1
+3

applications/lazstats/data/genkappa.laz

@@ -0,0 +1,87 @@
+15
+3
+rater
+VARIABLE 1
+1
+I
+0
+99999
+L
+object
+VARIABLE 2
+1
+I
+0
+99999
+L
+category
+VARIABLE 3
+1
+I
+0
+99999
+L
+Case 0
+rater
+object
+category
+Case 1
+1
+1
+1
+Case 2
+1
+2
+2
+Case 3
+1
+3
+3
+Case 4
+1
+4
+2
+Case 5
+1
+5
+3
+Case 6
+2
+1
+1
+Case 7
+2
+2
+2
+Case 8
+2
+3
+2
+Case 9
+2
+4
+3
+Case 10
+2
+5
+3
+Case 11
+3
+1
+1
+Case 12
+3
+2
+2
+Case 13
+3
+3
+3
+Case 14
+3
+4
+2
+Case 15
+3
+5
+3

applications/lazstats/source/forms/analysis/nonparametric/genkappaunit.lfm

@@ -13,92 +13,74 @@ object GenKappaFrm: TGenKappaFrm
   Position = poMainFormCenter
   LCLVersion = '2.1.0.0'
   object ResetBtn: TButton
-    AnchorSideRight.Control = CancelBtn
+    AnchorSideRight.Control = ComputeBtn
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 167
+    Left = 259
     Height = 25
     Top = 323
     Width = 54
     Anchors = [akRight, akBottom]
     AutoSize = True
-    BorderSpacing.Left = 12
+    BorderSpacing.Left = 8
     BorderSpacing.Top = 8
-    BorderSpacing.Right = 12
+    BorderSpacing.Right = 8
     BorderSpacing.Bottom = 8
     Caption = 'Reset'
     OnClick = ResetBtnClick
     TabOrder = 2
   end
-  object CancelBtn: TButton
-    AnchorSideRight.Control = ComputeBtn
-    AnchorSideBottom.Control = Owner
-    AnchorSideBottom.Side = asrBottom
-    Left = 233
-    Height = 25
-    Top = 323
-    Width = 62
-    Anchors = [akRight, akBottom]
-    AutoSize = True
-    BorderSpacing.Left = 12
-    BorderSpacing.Top = 8
-    BorderSpacing.Right = 12
-    BorderSpacing.Bottom = 8
-    Caption = 'Cancel'
-    ModalResult = 2
-    TabOrder = 3
-  end
   object ComputeBtn: TButton
-    AnchorSideRight.Control = ReturnBtn
+    AnchorSideRight.Control = CloseBtn
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 307
+    Left = 321
     Height = 25
     Top = 323
     Width = 76
     Anchors = [akRight, akBottom]
     AutoSize = True
-    BorderSpacing.Left = 12
+    BorderSpacing.Left = 8
     BorderSpacing.Top = 8
-    BorderSpacing.Right = 12
+    BorderSpacing.Right = 8
     BorderSpacing.Bottom = 8
     Caption = 'Compute'
     OnClick = ComputeBtnClick
-    TabOrder = 4
+    TabOrder = 3
   end
-  object ReturnBtn: TButton
+  object CloseBtn: TButton
     AnchorSideRight.Control = Owner
     AnchorSideRight.Side = asrBottom
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 395
+    Left = 405
     Height = 25
     Top = 323
-    Width = 61
+    Width = 55
     Anchors = [akRight, akBottom]
     AutoSize = True
-    BorderSpacing.Left = 12
+    BorderSpacing.Left = 8
     BorderSpacing.Top = 8
-    BorderSpacing.Right = 12
+    BorderSpacing.Right = 8
     BorderSpacing.Bottom = 8
-    Caption = 'Return'
+    Caption = 'Close'
-    ModalResult = 1
+    ModalResult = 11
-    TabOrder = 5
+    TabOrder = 4
   end
   object HelpBtn: TButton
     Tag = 125
     AnchorSideRight.Control = ResetBtn
     AnchorSideBottom.Control = Owner
     AnchorSideBottom.Side = asrBottom
-    Left = 104
+    Left = 200
     Height = 25
     Top = 323
     Width = 51
     Anchors = [akRight, akBottom]
     AutoSize = True
-    BorderSpacing.Left = 12
+    BorderSpacing.Left = 8
     BorderSpacing.Top = 8
-    BorderSpacing.Right = 12
+    BorderSpacing.Right = 8
     BorderSpacing.Bottom = 8
     Caption = 'Help'
     OnClick = HelpBtnClick
@@ -195,6 +177,7 @@ object GenKappaFrm: TGenKappaFrm
       BorderSpacing.Top = 2
       BorderSpacing.Right = 8
       ItemHeight = 0
+      OnSelectionChange = VarListSelectionChange
       TabOrder = 0
     end
     object CatIn: TBitBtn
@@ -306,6 +289,7 @@ object GenKappaFrm: TGenKappaFrm
       Anchors = [akLeft, akRight, akBottom]
       BorderSpacing.Left = 8
       BorderSpacing.Bottom = 12
+      ReadOnly = True
       TabOrder = 3
       Text = 'CatEdit'
     end
@@ -323,8 +307,9 @@ object GenKappaFrm: TGenKappaFrm
       Anchors = [akLeft, akRight, akBottom]
       BorderSpacing.Left = 8
       BorderSpacing.Bottom = 12
+      ReadOnly = True
       TabOrder = 6
-      Text = 'Edit1'
+      Text = 'ObjectEdit'
     end
     object RaterEdit: TEdit
       AnchorSideLeft.Control = RaterOut
@@ -341,8 +326,9 @@ object GenKappaFrm: TGenKappaFrm
       Anchors = [akLeft, akRight, akBottom]
       BorderSpacing.Left = 8
       BorderSpacing.Bottom = 12
+      ReadOnly = True
       TabOrder = 9
-      Text = 'Edit1'
+      Text = 'RaterEdit'
     end
   end
 end

applications/lazstats/source/forms/analysis/nonparametric/genkappaunit.pas

@@ -1,3 +1,7 @@
+// File for testing according to pdf help: KappaTest3.laz
+// BUT: Yields different results than pdf
+// --> using file genkappa.laz for the chm
+
 unit GenKappaUnit;
 
 {$mode objfpc}{$H+}
@@ -18,9 +22,8 @@ type
     Label4: TLabel;
     Panel1: TPanel;
     ResetBtn: TButton;
-    CancelBtn: TButton;
     ComputeBtn: TButton;
-    ReturnBtn: TButton;
+    CloseBtn: TButton;
     CatIn: TBitBtn;
     CatOut: TBitBtn;
     CatEdit: TEdit;
@@ -46,6 +49,7 @@ type
     procedure RaterInClick(Sender: TObject);
     procedure RaterOutClick(Sender: TObject);
     procedure ResetBtnClick(Sender: TObject);
+    procedure VarListSelectionChange(Sender: TObject; User: boolean);
   private
     { private declarations }
     FAutoSized: Boolean;
@@ -55,11 +59,12 @@ type
     function compute_term1(R: IntDyneCube; i, j, k: integer): double;
     function compute_term2(R: IntDyneCube; i, j, l: integer): double;
     function compute_denom(R: IntDyneCube): double;
-    function compute_partial_pchance(R : IntDyneCube; i, j : integer;
+    function compute_partial_pchance(R: IntDyneCube; i, j: integer; denom: double): double;
-                denom : double) : double;
     function compute_partial_pobs(R: IntDyneCube; k, l: integer): double;
     function KappaVariance(R: IntDyneCube; n, m, K1: integer): double;
 
+    procedure UpdateBtnStates;
+
   public
     { public declarations }
   end; 
@@ -70,7 +75,7 @@ var
 implementation
 
 uses
-  Math;
+  Math, Utils;
 
 { TGenKappaFrm }
 
@@ -92,110 +97,98 @@ begin
 end;
 
 procedure TGenKappaFrm.CatInClick(Sender: TObject);
-VAR index : integer;
+var
+  index: integer;
 begin
   index := VarList.ItemIndex;
-     CatEdit.Text := VarList.Items.Strings[index];
+  if (index > -1) and (CatEdit.Text = '') then
+  begin
+    CatEdit.Text := VarList.Items[index];
     VarList.Items.Delete(index);
-     CatIn.Enabled := false;
+    UpdateBtnStates;
-     CatOut.Enabled := true;
+  end;
 end;
 
 procedure TGenKappaFrm.CatOutClick(Sender: TObject);
+begin
+  if CatEdit.Text <> '' then
   begin
     VarList.Items.Add(CatEdit.Text);
     CatEdit.Text := '';
-     CatIn.Enabled := true;
+    UpdateBtnStates;
-     CatOut.Enabled := false;
+  end;
 end;
 
 procedure TGenKappaFrm.ComputeBtnClick(Sender: TObject);
-VAR
+var
   CatCol, ObjCol, RaterCol, frequency, i, j, k, l: integer;
   value, rater, category, anobject: integer;
-//     int CatCol:=0, ObjCol:=0, RaterCol:=0;
-//     int value, rater, category, object;
   R: IntDyneCube;
-//     int ***R;
   pobs, pchance, kappa, num, denom, partial_pchance, a_priori: double;
   average_frequency: DblDyneVec;
-     outline : array[0..131] of char;
-//     char outline[131], astring[21];
   z: double;
-
+  lReport: TStrings;
 begin
+  lReport := TStringList.Create;
+  try
+    lReport.Add('GENERALIZED KAPPA COEFFICIENT PROCEDURE');
+    lReport.Add('Adapted from the program written by Giovanni Flammia');
+    lReport.Add('Copy-write 1995, M.I.T. Lab. for Computer Science');
+    lReport.Add('');
+
+    // get columns for the variables
     CatCol := 0;
     ObjCol := 0;
     RaterCol := 0;
-     OutputFrm.RichEdit.Clear;
+    for i := 1 to NoVariables do
-     OutputFrm.RichEdit.Lines.Add('Generalized Kappa Coefficient Procedure');
-     OutputFrm.RichEdit.Lines.Add('adapted from the program written by Giovanni Flammia');
-     OutputFrm.RichEdit.Lines.Add('copywritten 1995, M.I.T. Lab. for Computer Science');
-     OutputFrm.RichEdit.Lines.Add('');
-
-     // get columns for the variables
-     for i := 0 to NoVariables - 1 do
     begin
-         if (OS3MainFrm.DataGrid.Cells[i+1,0] = CatEdit.Text) then CatCol := i+1;
+      if (OS3MainFrm.DataGrid.Cells[i, 0] = CatEdit.Text) then CatCol := i;
-         if (OS3MainFrm.DataGrid.Cells[i+1,0] = RaterEdit.Text) then RaterCol := i+1;
+      if (OS3MainFrm.DataGrid.Cells[i, 0] = RaterEdit.Text) then RaterCol := i;
-         if (OS3MainFrm.DataGrid.Cells[i+1,0] = ObjectEdit.Text) then ObjCol := i+1;
+      if (OS3MainFrm.DataGrid.Cells[i, 0] = ObjectEdit.Text) then ObjCol := i;
     end;
     if ((CatCol = 0) or (RaterCol = 0) or (ObjCol = 0)) then
     begin
-         ShowMessage('ERROR!  One or more variables not defined.');
+      MessageDlg('One or more variables not defined.', mtError, [mbOK], 0);
       exit;
     end;
+
     // get max no of codes for objects, raters, categories
     NoCats := 0;
     NoObjects := 0;
     NoRaters := 0;
-     for i := 0 to NoCases - 1 do
+    for i := 1 to NoCases do
     begin
-         value := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[CatCol,i+1]));
+      value := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[CatCol, i])));
-//        result := GetValue(i+1,CatCol,intvalue,dblvalue,strvalue);
-//         if (result :=:= 1) value := 0;
-//         else value := intvalue;
       if (value > NoCats) then NoCats := value;
-         value := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[ObjCol,i+1]));
+
-//         result := GetValue(i+1,ObjCol,intvalue,dblvalue,strvalue);
+      value := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[ObjCol, i])));
-//         if (result :=:= 1) value := 0;
-//         else value := intvalue;
       if (value > NoObjects) then NoObjects := value;
-         value := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[RaterCol,i+1]));
+
-//         result := GetValue(i+1,RaterCol,intvalue,dblvalue,strvalue);
+      value := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[RaterCol, i])));
-//         if (result :=:= 1) value := 0;
-//         else value := intvalue;
       if (value > NoRaters) then NoRaters := value;
     end;
 
-     outline := format('%d Raters using %d Categories to rate %d Objects',
+    lReport.Add('%d Raters using %d Categories to rate %d Objects', [NoRaters, NoCats, NoObjects]);
-         [NoRaters, NoCats, NoObjects]);
+    lReport.Add('');
-     OutputFrm.RichEdit.Lines.Add(outline);
-     OutputFrm.RichEdit.Lines.Add('');
 
     // get memory for R and set to zero
     SetLength(R, NoRaters+1, NoCats+1, NoObjects+1);
     for i := 0 to NoRaters - 1 do
-     begin
       for k := 0 to NoCats - 1 do
-         begin
         for l := 0 to NoObjects - 1 do
-             begin
           R[i,k,l] := 0;
-             end;
-         end;
-     end;
 
     // get memory for average_frequency
     SetLength(average_frequency, NoCats+1);
-     for k := 0 to NoCats - 1 do average_frequency[k] := 0.0;
+    for k := 0 to NoCats - 1 do
+      average_frequency[k] := 0.0;
 
     // read data and store in R
-     for i := 0 to NoCases - 1 do
+    for i := 1 to NoCases do
     begin
-         rater := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[RaterCol,i+1]));
+      rater := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[RaterCol, i])));
-         anobject := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[ObjCol,i+1]));
+      anobject := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[ObjCol, i])));
-         category := StrToInt(Trim(OS3MainFrm.DataGrid.Cells[CatCol,i+1]));
+      category := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[CatCol, i])));
       R[rater-1, category-1, anobject-1] := 1;
     end;
 
@@ -205,73 +198,60 @@ begin
     for i := 0 to NoRaters - 1 do
     begin
       for j := 0 to NoRaters - 1 do
-         begin
         if (i <> j) then
         begin
           partial_pchance := compute_partial_pchance(R,i,j,denom);
           pchance := pchance + partial_pchance;
         end;
-         end;
       for k := 0 to NoCats - 1 do
       begin
         frequency := 0;
         for l := 0 to NoObjects - 1 do
-             begin
           frequency := frequency + R[i,k,l];
-             end;
         a_priori := frequency / NoObjects;
-             outline := format('Frequency[%d,%d] := %f',[i+1,k+1,a_priori]);
+        lReport.Add('Frequency[%d,%d]: %f', [i+1, k+1, a_priori]);
-             OutputFrm.RichEdit.Lines.Add(outline);
       end;
     end;
 
     for k := 0 to NoCats - 1 do
-     begin
       for l := 0 to NoObjects - 1 do
-         begin
         for i := 0 to NoRaters - 1 do
-             begin
           average_frequency[k] := average_frequency[k] + R[i,k,l];
-             end;
-         end;
-     end;
 
     for k := 0 to NoCats - 1 do
     begin
       average_frequency[k] := average_frequency[k] / (NoObjects * NoRaters);
-         outline := format('Average_Frequency[%d] := %f',[k+1,average_frequency[k]]);
+      lReport.Add('Average_Frequency[%d]: %f', [k+1, average_frequency[k]]);
-         OutputFrm.RichEdit.Lines.Add(outline);
     end;
-     outline := format('PChance := %f',[pchance]);
+
-     OutputFrm.RichEdit.Lines.Add(outline);
+    lReport.Add('PChance: %f', [pchance]);
 
     // compute observed probability of agreement among all raters
     num := 0.0;
     for k := 0 to NoCats - 1 do
-     begin
       for l := 0 to NoObjects - 1 do
-         begin
         num := num + compute_partial_pobs(R,k,l);
-         end;
+    if (denom > 0.0) then
-     end;
+      pobs := num / denom
-     if (denom > 0.0) then pobs := num / denom
+    else
-     else pobs := 0.0;
+      pobs := 0.0;
-     outline := format('PObs := %f',[pobs]);
+    lReport.Add('PObs: %f', [pobs]);
-     OutputFrm.RichEdit.Lines.Add(outline);
 
     kappa := (pobs - pchance) / (1.0 - pchance);
-     outline := format('Kappa := %f',[kappa]);
+    lReport.Add('Kappa: %f', [kappa]);
-     OutputFrm.RichEdit.Lines.Add(outline);
+
     z := KappaVariance(R,NoObjects,NoRaters,NoCats);
     if (z > 0.0) then z := kappa / sqrt(z);
-     outline := format('z for Kappa := %8.3f with probability > %8.3f',[z,1.0-probz(z)]);
+    lReport.Add('z for Kappa: %.3f with probability > %.3f', [z, 1.0-probz(z)]);
-     OutputFrm.RichEdit.Lines.Add(outline);
-     OutputFrm.ShowModal;
 
-     // clean up space allocated
+    DisplayReport(lReport);
+
+  finally
+    lReport.Free;
     average_frequency := nil;
     R := nil;
   end;
+end;
 
 procedure TGenKappaFrm.FormActivate(Sender: TObject);
 var
@@ -279,12 +259,11 @@ var
 begin
   if FAutoSized then
     exit;
-  w := MaxValue([HelpBtn.Width, ResetBtn.Width, CancelBtn.Width, ComputeBtn.Width, ReturnBtn.Width]);
+  w := MaxValue([HelpBtn.Width, ResetBtn.Width, ComputeBtn.Width, CloseBtn.Width]);
   HelpBtn.Constraints.MinWidth := w;
   ResetBtn.Constraints.MinWidth := w;
-  CancelBtn.Constraints.MinWidth := w;
   ComputeBtn.Constraints.MinWidth := w;
-  ReturnBtn.Constraints.MinWidth := w;
+  CloseBtn.Constraints.MinWidth := w;
 
   Constraints.MinWidth := Width;
   Constraints.MinHeight := Height;
@@ -295,8 +274,6 @@ end;
 procedure TGenKappaFrm.FormCreate(Sender: TObject);
 begin
   Assert(OS3MainFrm <> nil);
-  if OutputFrm = nil then
-    Application.CreateForm(TOutputFrm, OutputFrm);
 end;
 
 procedure TGenKappaFrm.FormShow(Sender: TObject);
@@ -308,31 +285,29 @@ procedure TGenKappaFrm.HelpBtnClick(Sender: TObject);
 begin
   if ContextHelpForm = nil then
     Application.CreateForm(TContextHelpForm, ContextHelpForm);
-  ContextHelpForm.HelpMessage((Sender as TButton).tag);
+  ContextHelpForm.HelpMessage((Sender as TButton).Tag);
 end;
 
 function TGenKappaFrm.compute_term1(R: IntDyneCube; i, j, k: integer): double;
-VAR
+var
   kk : integer;            // range over 0 .. num_categories-1 */
   l,ll : integer;          // range over 0 .. num_points-1 */
   denom_i : integer;       //:=0;
   denom_j : integer;       //:=0;
   num_i : integer;         //:=0;
   num_j : integer;         //:=0;
-
 begin
   denom_i := 0;
   denom_j := 0;
   num_i := 0;
   num_j := 0;
+
   for kk := 0 to NoCats - 1 do
-  begin
     for ll := 0 to NoObjects - 1 do
     begin
       denom_i := denom_i + R[i, kk, ll];
       denom_j := denom_j + R[j, kk, ll];
     end;
-  end;
 
   for l := 0 to NoObjects - 1 do
   begin
@@ -340,11 +315,11 @@ begin
     num_j := num_j + R[j, k, l];
   end;
 
-  result := ((num_i / denom_i) * (num_j / denom_j));
+  result := (num_i * num_j) / (denom_i * denom_j); //((num_i / denom_i) * (num_j / denom_j));
 end;
 
 function TGenKappaFrm.compute_term2(R: IntDyneCube; i, j, l: integer): double;
-VAR
+var
   sum_i, sum_j, k: integer;
 begin
   sum_i := 0;
@@ -356,42 +331,34 @@ begin
     sum_j := sum_j + R[j, k, l];
   end;
 
-  result := (sum_i * sum_j );
+  Result := sum_i * sum_j;
 end;
 
-//---------------------------------------------------------------------------
-
 function TGenKappaFrm.compute_denom(R: IntDyneCube): double;
-VAR
+var
   sum: IntDyneVec;
-   aresult : double;
   i, k, l: integer;
 begin
-  aresult := 0;
+  Result := 0;
 
   SetLength(sum, NoObjects); //  sum := (int *)calloc(num_points,sizeof(int));
   for l := 0 to NoObjects - 1 do
   begin
     sum[l] := 0;
     for i := 0 to NoRaters - 1 do
-    begin
       for k := 0 to NoCats - 1 do
-      begin
          sum[l] := sum[l] + R[i,k,l];
   end;
-    end;
+
-  end;
   for l := 0 to NoObjects - 1 do
-  begin
+    Result := Result + sum[l] * (sum[l] - 1);
-    aresult := aresult + sum[l] * ( sum[l] - 1);
+
-  end;
   sum := nil;
-  result := aresult;
 end;
 
 function TGenKappaFrm.compute_partial_pchance(R: IntDyneCube; i, j: integer;
   denom: double): double;
-VAR
+var
   term1, term2: double;
   k, l: integer;
 begin
@@ -399,48 +366,42 @@ begin
   term2 := 0;
 
   for k := 0 to NoCats - 1 do
-  begin
     term1 := term1 + compute_term1(R,i,j,k);
-  end;
 
   for l := 0 to NoObjects - 1 do
-  begin
     term2 := term2 + compute_term2(R,i,j,l);
+
+  if (denom > 0.0) then
+    Result := term1 * term2 / denom
+  else
+    Result := 0.0;
 end;
-  if (denom > 0.0) then result := ( term1 * ( term2 / denom ) )
-  else result := 0.0;
-end;
-//---------------------------------------------------------------------------
 
 function TGenKappaFrm.compute_partial_pobs(R: IntDyneCube; k, l: integer): double;
-VAR
+var
   sum, i: integer;
 begin
   sum := 0;
-
   for i := 0 to NoRaters - 1 do
-  begin
     sum := sum + R[i, k, l];
+
+  Result := sum * (sum - 1);
 end;
 
-  result := (sum * (sum - 1));
+{ Calculates the variance of Kappa
-end;
+  R contains 1's or 0's for raters, categories and objects (row, col, slice)
-
+  m is number of raters
+  n is number of subjects
+  K1 is the number of categories }
 function TGenKappaFrm.KappaVariance(R : IntDyneCube; n, m, K1: integer): double;
-VAR
+var
-   xij, variance, term1, term2 : double;
+  xij, term1, term2: double;
   i, j, k: integer;
   pj: DblDyneVec;
-
 begin
-       // calculates the variance of Kappa
-       // R contains 1's or 0's for raters, categories and objects (row, col, slice)
-       // m is number of raters
-       // n is number of subjects
-       // K1 is the number of categories
-
   term1 := 0.0;
   term2 := 0.0;
+
   SetLength(pj,K1);
   for j := 0 to K1 - 1 do pj[j] := 0.0;
 
@@ -449,65 +410,96 @@ begin
   begin
     xij := 0.0;
     for i := 0 to m - 1 do // accross raters
-           begin
       for k := 0 to n - 1 do // accross objects
-               begin
         xij := xij + R[i,j,k];
-               end;
-           end;
            pj[j] := pj[j] + xij;
   end;
-       for j := 0 to K1 - 1 do pj[j] := pj[j] / (n * m);
+
+  for j := 0 to K1 - 1 do
+    pj[j] := pj[j] / (n * m);
+
   for j := 0 to K1 - 1 do
   begin
     term1 := term1 + (pj[j] * (1.0 - pj[j]));
     term2 := term2 + (pj[j] * (1.0 - pj[j]) * (1.0 - 2.0 * pj[j]));
   end;
+
   term1 := term1 * term1;
-       if ((term1 > 0) and (term2 > 0)) then
+  if (term1 > 0) and (term2 > 0) then
-           variance := (2.0 / (n * m * (m-1) * term1)) * (term1 - term2)
+    Result := (2.0 / (n * m * (m-1) * term1)) * (term1 - term2)
-       else variance := 0.0;
+  else
+    Result := 0.0;
+
   pj := nil;
-       result := variance;
 end;
 
 procedure TGenKappaFrm.ObjInClick(Sender: TObject);
-VAR index : integer;
+var
+  index: integer;
 begin
   index := VarList.ItemIndex;
-
+  if (index > -1) and (ObjectEdit.Text = '') then
-     ObjectEdit.Text := VarList.Items.Strings[index];
+  begin
+    ObjectEdit.Text := VarList.Items[index];
     VarList.Items.Delete(index);
-     ObjIn.Enabled := false;
+    UpdateBtnStates;
-     ObjOut.Enabled := true;
+  end;
 end;
 
 procedure TGenKappaFrm.ObjOutClick(Sender: TObject);
+begin
+  if ObjectEdit.Text <> '' then
   begin
     VarList.Items.Add(ObjectEdit.Text);
     ObjectEdit.Text := '';
-     ObjIn.Enabled := true;
+    UpdateBtnStates;
-     ObjOut.Enabled := false;
+  end;
 end;
 
 procedure TGenKappaFrm.RaterInClick(Sender: TObject);
-VAR index : integer;
+var
+  index: integer;
 begin
   index := VarList.ItemIndex;
-
+  if (index > -1) and (RaterEdit.Text = '') then
+  begin
     RaterEdit.Text := VarList.Items.Strings[index];
     VarList.Items.Delete(index);
-     RaterIn.Enabled := false;
+    UpdateBtnStates;
-     RaterOut.Enabled := true;
+  end;
 end;
 
 procedure TGenKappaFrm.RaterOutClick(Sender: TObject);
+begin
+  if RaterEdit.Text <> '' then
   begin
     VarList.Items.Add(RaterEdit.Text);
     RaterEdit.Text := '';
-     RaterIn.Enabled := true;
+    UpdateBtnStates;
-     RaterOut.Enabled := false;
   end;
+end;
+
+procedure TGenKappaFrm.UpdateBtnStates;
+var
+  lSelected: Boolean;
+begin
+  lSelected := AnySelected(VarList);
+
+  CatIn.Enabled := lSelected and (CatEdit.Text = '');
+  CatOut.Enabled := (CatEdit.Text <> '');
+
+  ObjIn.Enabled := lSelected and (ObjectEdit.Text = '');
+  ObjOut.Enabled := (ObjectEdit.Text <> '');
+
+  RaterIn.Enabled := lSelected and (RaterEdit.Text = '');
+  RaterOut.Enabled := (RaterEdit.Text <> '');
+end;
+
+procedure TGenKappaFrm.VarListSelectionChange(Sender: TObject; User: boolean);
+begin
+  UpdateBtnStates;
+end;
+
 
 initialization
   {$I genkappaunit.lrs}