LazStats: Minor refactoring of MannWhitUUnit

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@7813 8e941d3f-bd1b-0410-a28a-d453659cc2b4
This commit is contained in:
wp_xxyyzz
2020-10-26 17:25:06 +00:00
parent c0b84b8908
commit af63896d52

View File

@ -53,7 +53,7 @@ implementation
uses
Math,
Utils;
Utils, MatrixUnit, GridProcs;
{ TMannWhitUForm }
@ -74,17 +74,15 @@ var
Ranks: DblDyneMat = nil;
X: DblDyneMat = nil;
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, Temp : double;
cellstring, outline : string;
i, j, ind_var, dep_var, min_grp, max_grp, group, total_n: integer;
NoTies, NoTieGroups, n1, n2, nogroups, largestn: integer;
TieSum, score, t, SumT, Avg, z, prob, U, U2, SD: double;
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;
dep_var := 0;
for i := 1 to NoVariables do
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
ind_var := GetVariableIndex(OS3MainFrm.DataGrid, GrpEdit.Text);
dep_var := GetVariableIndex(OS3MainFrm.DataGrid, DepEdit.Text);
if ind_var = -1 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;
@ -144,121 +134,115 @@ begin
RankSums[i] := 0.0;
end;
// Get data
for i := 1 to NoCases do
begin
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;
if (group > 2) then
begin
ErrorMsg('Group codes must be 1 and 2!');
exit;
end;
group_count[group-1] := group_count[group-1] + 1;
X[i-1, 0] := score;
X[i-1, 1] := group;
end;
// Sort all scores in ascending order
for i := 1 to total_n - 1 do
begin
for j := i + 1 to total_n do
begin
if (X[i-1,0] > X[j-1,0]) then
begin
Exchange(X[i-1, 0], X[j-1, 0]);
Exchange(X[i-1, 1], X[j-1, 1]);
end;
end;
end;
// Store ranks
for i := 0 to total_n-1 do
begin
Ranks[i, 0] := i+1;
Ranks[i, 1] := X[i, 1];
end;
// Check for ties in ranks - replace with average rank and calculate
// T for each tie and sum of the T's
i := 1;
while i < total_n do
begin
j := i + 1;
TieSum := 0;
NoTies := 0;
while (j < total_n) do
begin
if (X[j-1,0] > X[i-1,0]) then
break;
if (X[j-1,0] = X[i-1,0]) then // match
begin
TieSum := TieSum + round(Ranks[j-1,0]);
NoTies := NoTies + 1;
end;
j := j + 1;
end;
if (NoTies > 0) then //At least one tie found
begin
TieSum := TieSum + Ranks[i-1,0];
NoTies := NoTies + 1;
Avg := TieSum / NoTies;
for j := i to i + NoTies - 1 do Ranks[j-1,0] := Avg;
t := Power(NoTies,3) - NoTies;
SumT := SumT + t;
NoTieGroups := NoTieGroups + 1;
i := i + (NoTies - 1);
end;
i := i + 1;
end; // next i
// Calculate sum of ranks in each group
for i := 0 to total_n-1 do
begin
group := round(Ranks[i, 1]);
RankSums[group-1] := RankSums[group-1] + Ranks[i, 0];
end;
// Calculate U for larger and smaller groups
n1 := group_count[0];
n2 := group_count[1];
if (n1 > n2) then
U := n1 * n2 + n1 * (n1 + 1) / 2.0 - RankSums[0]
else
U := n1 * n2 + n2 * (n2 + 1) / 2.0 - RankSums[1];
U2 := n1 * n2 - U;
SD := n1 * n2 * (n1 + n2 + 1) / 12.0;
SD := sqrt(SD);
if (U2 > U) then
z := (U2 - n1 * n2 / 2) / SD
else
z := (U - n1 * n2 / 2) / SD;
prob := 1.0 - probz(z);
// 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;
score := StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[dep_var,i]));
group := round(StrToFloat(Trim(OS3MainFrm.DataGrid.Cells[ind_var,i])));
group := group - min_grp + 1;
if (group > 2) then
begin
ErrorMsg('Group codes must be 1 and 2!');
exit;
end;
group_count[group-1] := group_count[group-1] + 1;
X[i-1,0] := score;
X[i-1,1] := group;
end;
// Sort all scores in ascending order
for i := 1 to total_n - 1 do
begin
for j := i + 1 to total_n do
begin
if (X[i-1,0] > X[j-1,0]) then
begin
Temp := X[i-1,0];
X[i-1,0] := X[j-1,0];
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
begin
Ranks[i-1,0] := i;
Ranks[i-1,1] := X[i-1,1];
end;
// Check for ties in ranks - replace with average rank and calculate
// T for each tie and sum of the T's
i := 1;
while i < total_n do
begin
j := i + 1;
TieSum := 0;
NoTies := 0;
while (j < total_n) do
begin
if (X[j-1,0] > X[i-1,0]) then
break;
if (X[j-1,0] = X[i-1,0]) then // match
begin
TieSum := TieSum + round(Ranks[j-1,0]);
NoTies := NoTies + 1;
end;
j := j + 1;
end;
if (NoTies > 0) then //At least one tie found
begin
TieSum := TieSum + Ranks[i-1,0];
NoTies := NoTies + 1;
Avg := TieSum / NoTies;
for j := i to i + NoTies - 1 do Ranks[j-1,0] := Avg;
t := Power(NoTies,3) - NoTies;
SumT := SumT + t;
NoTieGroups := NoTieGroups + 1;
i := i + (NoTies - 1);
end;
i := i + 1;
end; // next i
// Calculate sum of ranks in each group
for i := 1 to total_n do
begin
group := round(Ranks[i-1,1]);
RankSums[group-1] := RankSums[group-1] + Ranks[i-1,0];
end;
// Calculate U for larger and smaller groups
n1 := group_count[0];
n2 := group_count[1];
if (n1 > n2) then
U := n1 * n2 + n1 * (n1 + 1) / 2.0 - RankSums[0]
else
U := n1 * n2 + n2 * (n2 + 1) / 2.0 - RankSums[1];
U2 := n1 * n2 - U;
SD := n1 * n2 * (n1 + n2 + 1) / 12.0;
SD := sqrt(SD);
if (U2 > U) then
z := (U2 - n1 * n2 / 2) / SD
else
z := (U - n1 * n2 / 2) / SD;
prob := 1.0 - probz(z);
// Report results
lReport.Add(' Score Rank Group');
lReport.Add('');
for i := 1 to total_n do
lReport.Add('%10.2f %10.2f %10.0f', [X[i-1,0], Ranks[i-1,0], Ranks[i-1,1]]);
for i := 0 to total_n-1 do
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
lReport.Add('%3d %10.2f %5d', [i+min_grp-1, RankSums[i-1], group_count[i-1]]);
for i := 0 to noGroups-1 do
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