Hello,
I want to test if a sample is from a negative binomiale and to estimate
the parameters.
I have used two methods: a sas macro goodfit of Mr Friendly, and a
software called Bestfit.
The results are different. Bestfit seems to consider that the first
parameter is an integer. Goodfit gives non integer result. What are the
algorithms used in every case? What are the definitions of a negative
binomial for every of them?
A negative binomial in not obliged to have the first parameter integer
(see Univariate discrete distributions of Johnson and Co).
Is there an another way or an another software to calculate the
parameters of an neg binomiale?
Anouar
Ps: Genmod can not be used because the calculus are only asymptotic.
Here is a sample generated from Bestfit (with number of sucesses 20 , p=O.4)
for comparisons:
19
38
28
37
28
39
28
40
28
29
31
50
26
30
27
29
35
28
23
18
29
15
41
28
28
21
35
31
32
49
27
39
26
20
44
19
26
38
28
21
29
28
40
28
42
54
26
30
13
37
27
28
50
23
26
23
29
25
39
26
30
32
28
25
50
22
20
42
32
28
21
23
28
27
33
17
17
33
21
23
33
27
34
24
29
36
27
17
21
36
49
28
23
14
58
24
48
29
36
39
.
.
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