* Negative binomial Chapter
drop _all

input LOS count time
0  5.500    .
13 5.500   7.875
13 5.625   8.000
13 5.750  10.000
13 5.875   9.125
13 6.000   7.775
13 6.125   6.500
13 6.250   6.125
13 6.375   5.875
13 6.500    .
0  6.500    .
11 6.500   5.875
11 6.625   6.000
11 6.750   8.000
11 6.875   7.125
11 7.000   5.775
11 7.125   4.500
11 7.250   4.125
11 7.375   3.875
11 7.500    .
0  7.500    .
8  7.500   2.875
8  7.625   3.000
8  7.750   5.000
8  7.875   4.125
8  8.000   2.775
8  8.125   1.500
8  8.250   1.125
8  8.375   0.875
8  8.500    .
0  8.500    .
end

capture program drop doit
program define doit
     version 6.0                                                                                                                        
	graph LOS time count, c(l.) s(.o) xlab(5,6,7,8,9) ylab(0,1,2,3,4,5,6,7,8,9,10,11,12,13) /*
		*/ l2("Count") b2("LOS") t2("Discharges follow Gamma distribution") saving(negbin, replace)
end
doit
graph export negbin.eps, replace


use medpar, clear
nbreg los hmo white type2 type3, irr nolog
glm los hmo white type2 type3, family(nb .4457567) eform nolog

negbin los hmo white type2 type3, eform

use doll, clear
glm deaths smokes a2-a5, family(nb 0.000001) lnoffset(pyears) eform nolog

drop _all
input LOS count
1  50
2  40
3  30
4  20
5  15
6  12
7  10
8   7
9   6
10  6
11  5
12  5
13  4
14  3
15  2
16  0
end

capture program drop doit
program define doit
	version 6.0
	graph count LOS, xlab(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16) ylab(0,2,4,6,8,10,20,30,40,50) /*
		*/ c(.) s(o) saving(geomlos, replace)
end
doit
graph export geomlos.eps, replace


use medpar, clear
glm los white type2 type3, family(nb 1) link(nb) eform nolog

glm los white type2 type3, family(nb 1) link(nb) irls scale(dev) eform nolog noheader
glm los white type2 type3, family(nb 1) link(nb) cluster(provnum) eform nolog noheader