1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
{ ******************************************************************
Snedecor's F-test (comparison of two variances)
****************************************************************** }
unit usnedeco;
interface
uses
utypes;
procedure Snedecor(N1, N2 : Integer;
S1, S2 : Float;
var F : Float;
var DoF1, DoF2 : Integer);
{ ------------------------------------------------------------------
Snedecor's F-test (comparison of two variances)
------------------------------------------------------------------
Input parameters : N1, N2 = samples sizes
S1, S2 = samples SD's (computed with StDev)
Output parameters: F = Snedecor's F
DoF1, DoF2 = degrees of freedom
------------------------------------------------------------------ }
implementation
procedure Snedecor(N1, N2 : Integer;
S1, S2 : Float;
var F : Float;
var DoF1, DoF2 : Integer);
var
V1, V2 : Float; { Sample variances }
begin
V1 := Sqr(S1);
V2 := Sqr(S2);
if V1 > V2 then
begin
F := V1 / V2;
DoF1 := N1 - 1;
DoF2 := N2 - 1;
end
else
begin
F := V2 / V1;
DoF1 := N2 - 1;
DoF2 := N1 - 1;
end;
end;
end.
|
