LazStats: Minor refactoring of MannWhitUUnit

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7813 8e941d3f-bd1b-0410-a28a-d453659cc2b4

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

@@ -53,7 +53,7 @@ implementation
 
 uses
   Math,
-  Utils;
+  Utils, MatrixUnit, GridProcs;
 
 { TMannWhitUForm }
 
@@ -76,15 +76,13 @@ var
   RankSums: DblDyneVec = nil;
   i, j, ind_var, dep_var, min_grp, max_grp, group, total_n: integer;
   NoTies, NoTieGroups, n1, n2, nogroups, largestn: integer;
-  NoSelected : integer;
+  TieSum, score, t, SumT, Avg, z, prob, U, U2, SD: double;
-  TieSum, score, t, SumT, Avg, z, prob, U, U2, SD, Temp : double;
+  outline: string;
-  cellstring, outline : string;
   lReport: TStrings;
 
 begin
   total_n := 0;
   NoTieGroups := 0;
-  NoSelected := 2;
   SumT := 0.0;
 
   // Check for data
@@ -94,38 +92,30 @@ begin
     exit;
   end;
 
-  // allocate space
-  SetLength(ColNoSelected, NoVariables);
-
   // Get column numbers of the independent and dependent variables
-  ind_var := 0;
+  ind_var := GetVariableIndex(OS3MainFrm.DataGrid, GrpEdit.Text);
-  dep_var := 0;
+  dep_var := GetVariableIndex(OS3MainFrm.DataGrid, DepEdit.Text);
-  for i := 1 to NoVariables do
+  if ind_var = -1 then
-  begin
-    cellstring := GrpEdit.Text;
-    if (cellstring = OS3MainFrm.DataGrid.Cells[i,0]) then ind_var := i;
-    cellstring := DepEdit.Text;
-    if (cellstring = OS3MainFrm.DataGrid.Cells[i,0]) then dep_var := i;
-  end;
-  ColNoSelected[0] := ind_var;
-  ColNoSelected[1] := dep_var;
-  if ind_var = 0 then
   begin
     ErrorMsg('No group variable.');
     exit;
   end;
-  if dep_var = 0 then
+  if dep_var = -1 then
   begin
     ErrorMsg('No dependent variable.');
     exit;
   end;
 
+  SetLength(ColNoSelected, 2);
+  ColNoSelected[0] := ind_var;
+  ColNoSelected[1] := dep_var;
+
   //get minimum and maximum group codes
   min_grp := MaxInt;
   max_grp := -MaxInt;
   for i := 1 to NoCases do
   begin
-    if (not GoodRecord(i, NoSelected, ColNoSelected)) then continue;
+    if (not GoodRecord(OS3MainFrm.DataGrid, i, ColNoSelected)) then continue;
     group := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[ind_var,i])));
     if (group < min_grp) then min_grp := group;
     if (group > max_grp) then max_grp := group;
@@ -144,17 +134,10 @@ begin
     RankSums[i] := 0.0;
   end;
 
-  // Setup for printer output
-  lReport := TStringList.Create;
-  try
-    lReport.Add('MANN-WHITNEY U TEST');
-    lReport.Add('See pages 116-127 in S. Siegel: Nonparametric Statistics for the Behavioral Sciences');
-    lReport.Add('');
-
   // Get data
   for i := 1 to NoCases do
   begin
-      if (not GoodRecord(i,NoSelected,ColNoSelected)) then continue;
+    if (not GoodRecord(OS3mainFrm.DataGrid, i, ColNoSelected)) then continue;
     score := StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[dep_var,i]));
     group := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[ind_var,i])));
     group := group - min_grp + 1;
@@ -175,21 +158,17 @@ begin
     begin
       if (X[i-1,0] > X[j-1,0]) then
       begin
-          Temp := X[i-1,0];
+        Exchange(X[i-1, 0], X[j-1, 0]);
-          X[i-1,0] := X[j-1,0];
+        Exchange(X[i-1, 1], X[j-1, 1]);
-          X[j-1,0] := Temp;
-          Temp := X[i-1,1];
-          X[i-1,1] := X[j-1,1];
-          X[j-1,1] := Temp;
       end;
     end;
   end;
 
   // Store ranks
-    for i := 1 to total_n do
+  for i := 0 to total_n-1 do
   begin
-      Ranks[i-1,0] := i;
+    Ranks[i, 0] := i+1;
-      Ranks[i-1,1] := X[i-1,1];
+    Ranks[i, 1] := X[i, 1];
   end;
 
   // Check for ties in ranks - replace with average rank and calculate
@@ -227,10 +206,10 @@ begin
   end; // next i
 
   // Calculate sum of ranks in each group
-    for i := 1 to total_n do
+  for i := 0 to total_n-1 do
   begin
-      group := round(Ranks[i-1,1]);
+    group := round(Ranks[i, 1]);
-      RankSums[group-1] := RankSums[group-1] + Ranks[i-1,0];
+    RankSums[group-1] := RankSums[group-1] + Ranks[i, 0];
   end;
 
   // Calculate U for larger and smaller groups
@@ -249,16 +228,21 @@ begin
     z := (U - n1 * n2 / 2) / SD;
   prob := 1.0 - probz(z);
 
-    // Report results
+  // Setup for printer output
+  lReport := TStringList.Create;
+  try
+    lReport.Add('MANN-WHITNEY U TEST');
+    lReport.Add('See pages 116-127 in S. Siegel: Nonparametric Statistics for the Behavioral Sciences');
+    lReport.Add('');
     lReport.Add('     Score       Rank      Group');
     lReport.Add('');
-    for i := 1 to total_n do
+    for i := 0 to total_n-1 do
-      lReport.Add('%10.2f %10.2f %10.0f', [X[i-1,0], Ranks[i-1,0], Ranks[i-1,1]]);
+      lReport.Add('%10.2f %10.2f %10.0f', [X[i,0], Ranks[i,0], Ranks[i,1]]);
     lReport.Add('');
     lReport.Add('Sum of Ranks in each Group');
     lReport.Add('Group   Sum    No. in Group');
-    for i := 1 to nogroups do
+    for i := 0 to noGroups-1 do
-      lReport.Add('%3d  %10.2f %5d',  [i+min_grp-1, RankSums[i-1], group_count[i-1]]);
+      lReport.Add('%3d  %10.2f %5d',  [i+min_grp, RankSums[i], group_count[i]]);
     lReport.Add('');
     lReport.Add('No. of tied rank groups:        %10d', [NoTieGroups]);
     if (n1 > n2) then