LazStats: Fix bug in NormalDist. Nicer report layout in CompareDistUnit.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7724 8e941d3f-bd1b-0410-a28a-d453659cc2b4

applications/lazstats/source/forms/analysis/descriptive/comparedistunit.lfm

@@ -527,13 +527,13 @@ inherited CompareDistFrm: TCompareDistFrm
     Height = 519
     Top = 8
     Width = 599
-    ActivePage = CumFreqChartPage
+    ActivePage = ReportPage
     Align = alClient
     BorderSpacing.Left = 4
     BorderSpacing.Top = 8
     BorderSpacing.Right = 8
     BorderSpacing.Bottom = 8
-    TabIndex = 1
+    TabIndex = 0
     TabOrder = 1
     object ReportPage: TTabSheet
       Caption = 'Report'

applications/lazstats/source/forms/analysis/descriptive/comparedistunit.pas

@@ -80,25 +80,39 @@ type
     FAutoSized: Boolean;
     CompareTo: TCompareTo;
     CompareDist: TCompareDist;
+
     procedure CalcFreq(XValues, FreqValues, CumFreqValues: DblDyneVec;
       AMin, AIncrement: Double; ANumIntervals, AColIndex: Integer);
+
     procedure CalcFreq(XValues, FreqValues, CumFreqValues: DblDyneVec;
       AMin, AMax: Double; ANumIntervals, ANumCases: Integer;
       ACompareDist: TCompareDist; DF1: Integer = -1; DF2: Integer = -1);
+
     procedure CalcIntervals(var AMin, AMax, AIntervalsize: Double;
       out ANumIntervals: Integer);
+
     function CalcMinMax(out AMin, AMax: Double; AColIndex: Integer): Integer;
+
     procedure CalcTheoreticalDist(XValues, FreqValues, CumFreqValues: DblDyneVec;
       ANumIntervals, ANumCases: Integer; ACompareDist: TCompareDist; out AName: String);
+
+    procedure DisplayReport(XValue1, XValue2, FreqValues1, FreqValues2,
+      CumFreqValues1, CumFreqValues2: DblDyneVec; AName1, AName2: String;
+      ANumIntervals: Integer);
+
     procedure Plot(AChartFrame: TChartFrame; Y1Values, Y2Values: DblDyneVec;
       ASeriesTitle1, ASeriesTitle2, AYTitle, ATitle: String);
+
     procedure UpdateBtnStates;
+
     procedure UpdateDF1;
+
     function Validate(ANumCases: Integer;
       out AMsg: String; out AControl: TWinControl): Boolean;
 
   public
     procedure Reset; override;
+
   end; 
 
 
@@ -272,35 +286,6 @@ begin
 end;
 
 
-
-(*
-  if NormalDistChk.Checked then // normal distribution curve
-  begin
-    name2 := 'Normal';
-    min2 := -3.0;
-    max2 := 3.0;
-    range2 := max2 - min2;
-    incrsize2 := range2 / noints;
-    Xvalue2[0] := min2;
-    Xvalue2[noints] := max2;
-    for i := 1 to noInts do
-    begin
-      Xvalue2[i-1] := min2 + (i-1) * incrSize2;
-      Xvalue2[i] := min2 + (i) * incrSize2;
-      prob1 := probz(abs(Xvalue2[i-1]));
-      prob2 := probz(abs(Xvalue2[i]));
-      if prob1 > prob2 then
-        Var2Freq[i-1] := round((prob1 - prob2) * nCases)
-      else
-        Var2Freq[i-1] := round((prob2 - prob1) * nCases)
-    end;
-    Cumfreq2[0] := Var2Freq[0];
-    for i := 1 to noints do
-      Cumfreq2[i] := Cumfreq2[i-1] + Var2Freq[i];
-  end
-end;
-*)
-
 procedure TCompareDistFrm.CloseBtnClick(Sender: TObject);
 begin
   Close;
@@ -326,10 +311,8 @@ var
   min1, max1, min2, max2: double;
   incrSize1: Double = 0.0;
   incrSize2: Double = 0.0;
-  KS: double;
+  name1, name2, msg: string;
-  cellVal, name1, name2, msg: string;
   C: TWinControl;
-  lReport: TStrings;
 begin
   // Get columns of the variables
   col1 := 0;
@@ -409,29 +392,7 @@ begin
   name1 := VarOneEdit.Text;
 
   // Print distributions to report
-  lReport := TStringList.Create;
+  DisplayReport(xValue1, xValue2, var1Freq, var2Freq, cumfreq1, cumFreq2, name1, name2, noInts);
-  try
-    lReport.Add('DISTRIBUTION COMPARISON by Bill Miller');
-    lReport.Add('');
-    lReport.Add('%10s   %10s   %10s   %10s   %10s   %10s', [
-      name1, name1, name1, name2, name2, name2
-    ]);
-    lReport.Add('%10s   %10s   %10s   %10s   %10s   %10s', [
-      'X1 Value', 'Frequency', 'Cum. Freq.', 'X2 Value', 'Frequency', 'Cum. Freq.'
-    ]);
-    lReport.Add('----------   ----------   ----------  ----------   ----------   ----------');
-    for i := 1 to noints do
-      lReport.Add('%10.3f   %10.0f   %10.3f   %10.3f   %10.0f   %10.3f', [
-        XValue1[i-1], Var1Freq[i-1], Cumfreq1[i-1], XValue2[i-1], Var2Freq[i-1], Cumfreq2[i-1]
-      ]);
-    lReport.Add('');
-    KS := KolmogorovTest(noInts, Cumfreq1, noInts, Cumfreq2, 'D', lReport);
-    lReport.Add('Kolmogorov-Smirnov statistic: %5.3f', [KS]);
-
-    FReportFrame.DisplayReport(lReport);
-  finally
-    lReport.Free;
-  end;
 
   // Plot the cumulative distributions
   Plot(FCumFreqChartFrame, cumFreq1, cumFreq2, VarOneEdit.Text, name2,
@@ -443,6 +404,75 @@ begin
       'Frequency', 'Plot of Distributions');
 
   FreqChartPage.TabVisible := BothChk.Checked;
+
+  (*
+  // Print distributions to report
+  name1 := CenterString(name1, 12);
+  name2 := CenterString(name2, 12);
+  lReport := TStringList.Create;
+  try
+    lReport.Add('DISTRIBUTION COMPARISON by Bill Miller');
+    lReport.Add('');
+    lReport.Add('%12s  %12s  %12s       %12s  %12s  %12s', [
+      name1, name1, name1, name2, name2, name2
+    ]);
+    lReport.Add('%12s  %12s  %12s       %12s  %12s  %12s', [
+      CenterString('X1 Value', 12), CenterString('Frequency', 12), CenterString('Cum. Freq.', 12),
+      CenterString('X2 Value', 12), CenterString('Frequency', 12), CenterString('Cum. Freq.', 12)
+    ]);
+    lReport.Add('------------  ------------  ------------       ------------  ------------  ------------');
+    for i := 1 to noints do
+      lReport.Add('%12.3f  %12.0f  %12.3f     %12.3f  %12.0f  %12.3f', [
+        XValue1[i-1], Var1Freq[i-1], Cumfreq1[i-1], XValue2[i-1], Var2Freq[i-1], Cumfreq2[i-1]
+      ]);
+    lReport.Add('');
+    KS := KolmogorovTest(noInts, Cumfreq1, noInts, Cumfreq2, '', lReport);
+    lReport.Add('Kolmogorov-Smirnov statistic: %5.3f', [KS]);
+
+    FReportFrame.DisplayReport(lReport);
+  finally
+    lReport.Free;
+  end;
+  *)
+end;
+
+
+procedure TCompareDistFrm.DisplayReport(XValue1, XValue2, FreqValues1, FreqValues2,
+  CumFreqValues1, CumFreqValues2: DblDyneVec; AName1, AName2: String;
+  ANumIntervals: Integer);
+var
+  lReport: TStrings;
+  i: Integer;
+  KS: Double;
+begin
+  AName1 := CenterString(AName1, 12);
+  AName2 := CenterString(AName2, 12);
+
+  lReport := TStringList.Create;
+  try
+    lReport.Add('DISTRIBUTION COMPARISON by Bill Miller');
+    lReport.Add('');
+    lReport.Add('%12s  %12s  %12s       %12s  %12s  %12s', [
+      AName1, AName1, AName1,  AName2, AName2, AName2
+    ]);
+    lReport.Add('%12s  %12s  %12s       %12s  %12s  %12s', [
+      CenterString('X1 Value', 12), CenterString('Frequency', 12), CenterString('Cum. Freq.', 12),
+      CenterString('X2 Value', 12), CenterString('Frequency', 12), CenterString('Cum. Freq.', 12)
+    ]);
+    lReport.Add('------------  ------------  ------------       ------------  ------------  ------------');
+    for i := 0 to ANumIntervals-1 do
+      lReport.Add('%12.3f  %12.0f  %12.3f     %12.3f  %12.0f  %12.3f', [
+        XValue1[i], FreqValues1[i], CumFreqValues1[i],
+        XValue2[i], FreqValues2[i], CumFreqValues2[i]
+      ]);
+    lReport.Add('');
+    KS := KolmogorovTest(ANumIntervals, CumFreqValues1, ANumIntervals, CumFreqValues2, '', lReport);
+    lReport.Add('Kolmogorov-Smirnov statistic: %5.3f', [KS]);
+
+    FReportFrame.DisplayReport(lReport);
+  finally
+    lReport.Free;
+  end;
 end;
 
 
@@ -553,6 +583,7 @@ begin
   AChartFrame.Clear;
 
   AChartFrame.SetTitle(ATitle);
+  AChartFrame.SetXTitle('Interval Index');
   AChartFrame.SetYTitle(AYTitle);
 
   if BarPlotBtn.Down then

applications/lazstats/source/units/mathunit.pas

@@ -139,7 +139,7 @@ begin
   if x < 0 then
     Result := (1.0 - erf(-x / SQRT2)) * 0.5
   else
-    Result := 0;
+    Result := 0.5;
 end;
 
 function NormalDistDensity(x, AMean, AStdDev: Double): Double;

applications/lazstats/source/units/utils.pas

@@ -28,15 +28,16 @@ procedure Exchange(var a, b: String); overload;
 procedure SortOnX(X: DblDyneVec; Y: DblDyneVec = nil; Z: DblDyneVec = nil);
 procedure SortOnX(X: DblDyneVec; Y: DblDyneMat);
 
-procedure QuickSortOnX(X: DblDyneVec; Y: DblDyneVec = nil; Z: DblDyneVec = nil);
+procedure QuickSortOnX(X: DblDyneVec; Y: DblDyneVec = nil; Z: DblDyneVec = nil);   // not 100% tested...
 
+function CenterString(S: String; Width: Integer): String;
 function IndexOfString(L: StrDyneVec; s: String): Integer;
 
 
 implementation
 
 uses
-  Math, ToolWin;
+  StrUtils, Math, ToolWin;
 
 // https://stackoverflow.com/questions/4093595/create-ttoolbutton-runtime
 procedure AddButtonToToolbar(AToolButton: TToolButton; AToolBar: TToolBar);
@@ -225,6 +226,28 @@ begin
   DoQuickSort(0, High(X));
 end;
 
+
+function CenterString(S: String; Width: Integer): String;
+var
+  n1, n2: Integer;
+begin
+  n1 := Width - Length(S);
+  if n1 <= 0 then
+  begin
+    Result := S;
+    exit;
+  end;
+
+  n1 := n1 div 2;
+  if Length(S) + 2*n1 < Width then
+    n2 := n1+1
+  else
+    n2 := n1;
+
+  Result := DupeString(' ', n1) + S + DupeString(' ', n2);
+end;
+
+
 function IndexOfString(L: StrDyneVec; s: String): Integer;
 var
   i: Integer;