zhijie zhang
2006-Oct-15 11:10 UTC
[R] gamma distribution don't allow negative value in GLMs?
Dear friends,
when i use glm() to fit my data, i use
glm(formula = snail ~ vegtype + mhveg + humidity + elevation + soiltem, *family
= Gamma(link = inverse),* data =a,))
It shows: error in eval(expr, envir, enclos) : *gamma distribution don't
allow negative value*.
But i use
result<-glm(formula = snail ~ vegtype + mhveg + humidity + elevation +
soiltem, family = poisson, data =a) #this works
In fact , there isn't any negative value in my dataset, who can tell me the
reason?
Thanks very much!
I copy my data here so you can check it:
vegtype mhveg humidity soiltem elevation snail
1 diluo 35.0 0.279851 21.1 low 162
2 diluo 25.0 0.316092 23.1 low 113
3 yuhao 35.0 0.297238 21.7 low 105
4 huanghuacai 1.5 0.310687 23.1 low 5
5 huanghuacai 2.0 0.267868 28.3 low 1
6 yuhao 25.0 0.290135 21.9 low 10
7 huanghuacai 1.0 0.285207 27.7 low 6
8 huanghuacai 2.0 0.252973 28.3 low 1
9 huanghuacai 1.5 0.270000 28.1 low 1
10 huanghuacai 2.5 0.300000 29.1 low 1
11 huanghuacai 2.0 0.296154 29.1 low 0
12 huanghuacai 2.0 0.302874 27.5 low 3
13 huanghuacai 1.5 0.301499 28.9 low 0
14 huanghuacai 3.0 0.291513 30.3 low 1
15 huanghuacai 1.0 0.273438 31.1 low 3
16 huanghuacai 1.5 0.290116 27.9 low 19
17 huanghuacai 2.5 0.198932 31.9 low 0
18 huanghuacai 2.0 0.390000 30.5 high 4
19 huanghuacai 2.5 0.282595 30.7 high 0
20 huanghuacai 1.0 0.266097 24.7 high 14
21 yuhao 30.0 0.240516 26.9 high 51
22 yuhao 35.0 0.227541 26.7 high 84
23 yuhao 20.0 0.252833 28.3 low 30
24 diluo 40.0 0.303030 27.9 low 91
25 hucao 80.0 0.303867 24.5 low 114
26 diluo 25.0 0.334948 26.7 low 115
27 hucao 60.0 0.306897 26.5 low 23
28 hucao 75.0 0.314465 25.7 low 43
29 yuhao 30.0 0.251783 26.1 low 77
30 diluo 10.0 0.277778 26.1 low 62
31 yuhao 25.0 0.291716 26.1 low 78
32 hucao 90.0 0.288800 24.5 low 35
33 diluo 25.0 0.337830 26.3 high 75
34 yuhao 13.0 0.296599 27.7 high 23
35 hucao 70.0 0.279498 26.3 high 116
36 diluo 3.0 0.281481 28.1 high 25
37 hucao 70.0 0.296000 23.7 high 83
38 diluo 10.0 0.272662 27.7 low 56
39 hucao 70.0 0.289796 25.3 high 112
40 diluo 5.0 0.339716 27.9 high 84
41 yuhao 35.0 0.231427 24.9 high 88
42 hucao 80.0 0.273810 24.1 high 134
43 yuhao 40.0 0.272789 25.1 high 53
44 yuhao 45.0 0.226036 25.1 high 88
45 yuhao 55.0 0.285495 23.9 high 76
46 hucao 80.0 0.252185 23.9 high 106
47 diluo 15.0 0.289933 24.5 high 194
48 hucao 95.0 0.261756 23.1 high 35
49 hucao 55.0 0.239819 24.7 high 21
50 hucao 75.0 0.254307 23.9 high 41
51 huanghuacai 1.0 0.286432 23.7 low 18
52 huanghuacai 2.0 0.301342 23.1 low 2
53 huanghuacai 2.0 0.369565 23.3 low 5
54 huanghuacai 1.5 0.245833 24.3 low 4
55 huanghuacai 1.0 0.315679 24.1 low 4
56 huanghuacai 2.5 0.296124 23.7 low 4
57 huanghuacai 2.0 0.312667 25.7 low 3
58 huanghuacai 3.0 0.300870 25.7 low 0
59 huanghuacai 2.0 0.303743 26.5 low 2
60 huanghuacai 1.0 0.269799 25.3 low 7
61 hucao 75.0 0.281250 22.5 low 14
62 yuhao 35.0 0.350350 23.3 low 63
63 hucao 65.0 0.304545 22.7 low 17
64 diluo 7.0 0.310056 24.9 low 45
65 hucao 80.0 0.288000 22.9 low 27
66 hucao 80.0 0.284211 22.7 low 46
67 diluo 25.0 0.281379 23.5 low 161
68 hucao 80.0 0.290533 23.3 low 117
69 yuhao 27.0 0.316568 24.1 low 106
70 yuhao 28.0 0.285156 25.1 low 82
71 yuhao 30.0 0.266667 24.5 low 55
72 hucao 85.0 0.290345 23.9 low 54
73 yuhao 35.0 0.315789 24.1 low 81
74 diluo 15.0 0.286598 28.3 low 102
75 yuhao 45.0 0.314211 24.1 low 85
76 yuhao 25.0 0.268794 25.1 low 63
77 hucao 80.0 0.275691 23.9 low 59
78 hucao 100.0 0.316614 24.1 low 46
79 yuhao 40.0 0.336683 25.5 low 70
80 diluo 20.0 0.270874 26.1 high 167
81 yuhao 50.0 0.271483 24.3 high 125
82 hucao 80.0 0.238095 25.1 high 200
83 yuhao 30.0 0.241202 26.7 low 122
85 diluo 35.0 0.244531 28.1 high 186
86 yuhao 55.0 0.274038 24.9 low 208
87 hucao 80.0 0.303488 25.7 low 87
88 hucao 85.0 0.278846 25.3 low 25
89 diluo 5.0 0.270330 28.3 high 18
90 yuhao 35.0 0.296296 24.7 high 21
91 diluo 1.0 0.274306 27.9 low 23
92 diluo 3.0 0.262673 29.5 low 0
93 diluo 8.0 0.268750 27.7 high 21
94 hucao 70.0 0.265734 26.1 high 2
95 hucao 85.0 0.275373 24.3 low 6
96 diluo 10.0 0.284091 27.1 low 2
97 hucao 85.0 0.268229 25.3 low 0
98 hucao 90.0 0.293056 23.9 low 0
99 yuhao 35.0 0.277483 24.7 low 3
100 hucao 95.0 0.286822 24.3 high 1
101 hucao 88.0 0.285946 23.9 high 5
102 yuhao 35.0 0.268313 24.5 low 1
103 yuhao 25.0 0.285714 24.3 high 0
104 yuhao 25.0 0.294675 24.5 high 2
105 yuhao 38.0 0.275385 23.5 high 6
106 hucao 92.0 0.302415 23.3 low 15
107 hucao 83.0 0.276190 23.9 low 5
108 yuhao 55.0 0.285068 24.1 low 20
109 hucao 80.0 0.276552 23.5 low 5
110 hucao 95.0 0.281818 23.9 low 0
111 hucao 105.0 0.270293 23.1 low 13
112 hucao 95.0 0.291209 20.1 low 23
113 hucao 90.0 0.273196 20.9 low 48
114 yuhao 27.0 0.261986 20.5 low 49
115 yuhao 40.0 0.265187 20.5 low 9
116 yuhao 27.0 0.307143 20.9 low 27
117 yuhao 33.0 0.293194 20.7 low 34
118 yuhao 25.0 0.211399 20.9 low 38
119 yuhao 20.0 0.277372 21.7 low 30
120 hucao 95.0 0.346224 20.5 low 88
121 hucao 90.0 0.330380 21.3 low 91
122 yuhao 23.0 0.337884 23.3 low 70
123 hucao 80.0 0.322488 22.3 low 103
124 hucao 80.0 0.300000 22.1 low 51
125 hucao 100.0 0.326241 21.7 low 82
126 hucao 95.0 0.298571 21.9 low 104
127 hucao 95.0 0.296029 21.7 low 39
128 hucao 85.0 0.260082 21.7 low 73
129 hucao 93.0 0.304167 21.9 low 103
130 hucao 90.0 0.289941 22.3 low 65
131 hucao 85.0 0.339189 22.7 low 112
132 yuhao 30.0 0.314103 23.3 low 32
133 yuhao 28.0 0.293464 23.5 low 29
134 yuhao 45.0 0.310256 23.3 low 92
135 yuhao 42.0 0.375573 23.1 low 49
136 hucao 90.0 0.313846 23.1 low 47
137 yuhao 25.0 0.303601 23.9 low 54
138 hucao 85.0 0.339394 23.3 low 64
139 hucao 90.0 0.285934 23.1 low 68
140 yuhao 27.0 0.327915 23.9 low 62
141 hucao 85.0 0.372679 23.9 low 94
142 hucao 85.0 0.350147 22.5 low 174
143 yuhao 35.0 0.278014 23.7 low 38
144 hucao 100.0 0.327273 22.9 low 105
145 hucao 68.0 0.309286 24.9 low 105
146 hucao 85.0 0.279503 24.3 high 60
147 hucao 95.0 0.310870 23.3 high 42
148 hucao 95.0 0.309353 24.3 high 64
149 hucao 92.0 0.280745 23.5 low 37
150 yuhao 25.0 0.300355 24.3 high 107
151 yuhao 40.0 0.307692 24.7 high 86
152 hucao 40.0 0.273292 25.3 high 72
153 hucao 53.0 0.305096 24.7 high 109
154 hucao 50.0 0.306288 24.7 high 76
155 hucao 95.0 0.312268 22.3 low 60
156 hucao 90.0 0.301170 22.7 low 62
157 yuhao 38.0 0.305109 22.9 low 68
158 hucao 25.0 0.300719 25.3 low 21
159 hucao 80.0 0.252149 23.1 low 50
160 hucao 90.0 0.290306 23.3 low 63
161 hucao 33.0 0.293772 25.1 low 63
--
With Kind Regards,
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Zhi Jie,Zhang ,PHD
Tel:86-21-54237149 epistat@gmail.com
Dept. of Epidemiology,school of public health,Fudan University
Address:No. 138 Yi Xue Yuan Road,Shanghai,China
Postcode:200032
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[[alternative HTML version deleted]]
I think the 0 values for snail are hurting you. Kees On Sunday 15 October 2006 13:10, zhijie zhang wrote:> Dear friends, > when i use glm() to fit my data, i use > glm(formula = snail ~ vegtype + mhveg + humidity + elevation + soiltem, > *family = Gamma(link = inverse),* data =a,)) > It shows: error in eval(expr, envir, enclos) : *gamma distribution don't > allow negative value*. > > But i use > result<-glm(formula = snail ~ vegtype + mhveg + humidity + elevation + > soiltem, family = poisson, data =a) #this works > In fact , there isn't any negative value in my dataset, who can tell me > the reason? > Thanks very much! > I copy my data here so you can check it: > vegtype mhveg humidity soiltem elevation snail > 1 diluo 35.0 0.279851 21.1 low 162 > 2 diluo 25.0 0.316092 23.1 low 113 > 3 yuhao 35.0 0.297238 21.7 low 105 > 4 huanghuacai 1.5 0.310687 23.1 low 5 > 5 huanghuacai 2.0 0.267868 28.3 low 1 > 6 yuhao 25.0 0.290135 21.9 low 10 > 7 huanghuacai 1.0 0.285207 27.7 low 6 > 8 huanghuacai 2.0 0.252973 28.3 low 1 > 9 huanghuacai 1.5 0.270000 28.1 low 1 > 10 huanghuacai 2.5 0.300000 29.1 low 1 > 11 huanghuacai 2.0 0.296154 29.1 low 0 > 12 huanghuacai 2.0 0.302874 27.5 low 3 > 13 huanghuacai 1.5 0.301499 28.9 low 0 > 14 huanghuacai 3.0 0.291513 30.3 low 1 > 15 huanghuacai 1.0 0.273438 31.1 low 3 > 16 huanghuacai 1.5 0.290116 27.9 low 19 > 17 huanghuacai 2.5 0.198932 31.9 low 0 > 18 huanghuacai 2.0 0.390000 30.5 high 4 > 19 huanghuacai 2.5 0.282595 30.7 high 0 > 20 huanghuacai 1.0 0.266097 24.7 high 14 > 21 yuhao 30.0 0.240516 26.9 high 51 > 22 yuhao 35.0 0.227541 26.7 high 84 > 23 yuhao 20.0 0.252833 28.3 low 30 > 24 diluo 40.0 0.303030 27.9 low 91 > 25 hucao 80.0 0.303867 24.5 low 114 > 26 diluo 25.0 0.334948 26.7 low 115 > 27 hucao 60.0 0.306897 26.5 low 23 > 28 hucao 75.0 0.314465 25.7 low 43 > 29 yuhao 30.0 0.251783 26.1 low 77 > 30 diluo 10.0 0.277778 26.1 low 62 > 31 yuhao 25.0 0.291716 26.1 low 78 > 32 hucao 90.0 0.288800 24.5 low 35 > 33 diluo 25.0 0.337830 26.3 high 75 > 34 yuhao 13.0 0.296599 27.7 high 23 > 35 hucao 70.0 0.279498 26.3 high 116 > 36 diluo 3.0 0.281481 28.1 high 25 > 37 hucao 70.0 0.296000 23.7 high 83 > 38 diluo 10.0 0.272662 27.7 low 56 > 39 hucao 70.0 0.289796 25.3 high 112 > 40 diluo 5.0 0.339716 27.9 high 84 > 41 yuhao 35.0 0.231427 24.9 high 88 > 42 hucao 80.0 0.273810 24.1 high 134 > 43 yuhao 40.0 0.272789 25.1 high 53 > 44 yuhao 45.0 0.226036 25.1 high 88 > 45 yuhao 55.0 0.285495 23.9 high 76 > 46 hucao 80.0 0.252185 23.9 high 106 > 47 diluo 15.0 0.289933 24.5 high 194 > 48 hucao 95.0 0.261756 23.1 high 35 > 49 hucao 55.0 0.239819 24.7 high 21 > 50 hucao 75.0 0.254307 23.9 high 41 > 51 huanghuacai 1.0 0.286432 23.7 low 18 > 52 huanghuacai 2.0 0.301342 23.1 low 2 > 53 huanghuacai 2.0 0.369565 23.3 low 5 > 54 huanghuacai 1.5 0.245833 24.3 low 4 > 55 huanghuacai 1.0 0.315679 24.1 low 4 > 56 huanghuacai 2.5 0.296124 23.7 low 4 > 57 huanghuacai 2.0 0.312667 25.7 low 3 > 58 huanghuacai 3.0 0.300870 25.7 low 0 > 59 huanghuacai 2.0 0.303743 26.5 low 2 > 60 huanghuacai 1.0 0.269799 25.3 low 7 > 61 hucao 75.0 0.281250 22.5 low 14 > 62 yuhao 35.0 0.350350 23.3 low 63 > 63 hucao 65.0 0.304545 22.7 low 17 > 64 diluo 7.0 0.310056 24.9 low 45 > 65 hucao 80.0 0.288000 22.9 low 27 > 66 hucao 80.0 0.284211 22.7 low 46 > 67 diluo 25.0 0.281379 23.5 low 161 > 68 hucao 80.0 0.290533 23.3 low 117 > 69 yuhao 27.0 0.316568 24.1 low 106 > 70 yuhao 28.0 0.285156 25.1 low 82 > 71 yuhao 30.0 0.266667 24.5 low 55 > 72 hucao 85.0 0.290345 23.9 low 54 > 73 yuhao 35.0 0.315789 24.1 low 81 > 74 diluo 15.0 0.286598 28.3 low 102 > 75 yuhao 45.0 0.314211 24.1 low 85 > 76 yuhao 25.0 0.268794 25.1 low 63 > 77 hucao 80.0 0.275691 23.9 low 59 > 78 hucao 100.0 0.316614 24.1 low 46 > 79 yuhao 40.0 0.336683 25.5 low 70 > 80 diluo 20.0 0.270874 26.1 high 167 > 81 yuhao 50.0 0.271483 24.3 high 125 > 82 hucao 80.0 0.238095 25.1 high 200 > 83 yuhao 30.0 0.241202 26.7 low 122 > 85 diluo 35.0 0.244531 28.1 high 186 > 86 yuhao 55.0 0.274038 24.9 low 208 > 87 hucao 80.0 0.303488 25.7 low 87 > 88 hucao 85.0 0.278846 25.3 low 25 > 89 diluo 5.0 0.270330 28.3 high 18 > 90 yuhao 35.0 0.296296 24.7 high 21 > 91 diluo 1.0 0.274306 27.9 low 23 > 92 diluo 3.0 0.262673 29.5 low 0 > 93 diluo 8.0 0.268750 27.7 high 21 > 94 hucao 70.0 0.265734 26.1 high 2 > 95 hucao 85.0 0.275373 24.3 low 6 > 96 diluo 10.0 0.284091 27.1 low 2 > 97 hucao 85.0 0.268229 25.3 low 0 > 98 hucao 90.0 0.293056 23.9 low 0 > 99 yuhao 35.0 0.277483 24.7 low 3 > 100 hucao 95.0 0.286822 24.3 high 1 > 101 hucao 88.0 0.285946 23.9 high 5 > 102 yuhao 35.0 0.268313 24.5 low 1 > 103 yuhao 25.0 0.285714 24.3 high 0 > 104 yuhao 25.0 0.294675 24.5 high 2 > 105 yuhao 38.0 0.275385 23.5 high 6 > 106 hucao 92.0 0.302415 23.3 low 15 > 107 hucao 83.0 0.276190 23.9 low 5 > 108 yuhao 55.0 0.285068 24.1 low 20 > 109 hucao 80.0 0.276552 23.5 low 5 > 110 hucao 95.0 0.281818 23.9 low 0 > 111 hucao 105.0 0.270293 23.1 low 13 > 112 hucao 95.0 0.291209 20.1 low 23 > 113 hucao 90.0 0.273196 20.9 low 48 > 114 yuhao 27.0 0.261986 20.5 low 49 > 115 yuhao 40.0 0.265187 20.5 low 9 > 116 yuhao 27.0 0.307143 20.9 low 27 > 117 yuhao 33.0 0.293194 20.7 low 34 > 118 yuhao 25.0 0.211399 20.9 low 38 > 119 yuhao 20.0 0.277372 21.7 low 30 > 120 hucao 95.0 0.346224 20.5 low 88 > 121 hucao 90.0 0.330380 21.3 low 91 > 122 yuhao 23.0 0.337884 23.3 low 70 > 123 hucao 80.0 0.322488 22.3 low 103 > 124 hucao 80.0 0.300000 22.1 low 51 > 125 hucao 100.0 0.326241 21.7 low 82 > 126 hucao 95.0 0.298571 21.9 low 104 > 127 hucao 95.0 0.296029 21.7 low 39 > 128 hucao 85.0 0.260082 21.7 low 73 > 129 hucao 93.0 0.304167 21.9 low 103 > 130 hucao 90.0 0.289941 22.3 low 65 > 131 hucao 85.0 0.339189 22.7 low 112 > 132 yuhao 30.0 0.314103 23.3 low 32 > 133 yuhao 28.0 0.293464 23.5 low 29 > 134 yuhao 45.0 0.310256 23.3 low 92 > 135 yuhao 42.0 0.375573 23.1 low 49 > 136 hucao 90.0 0.313846 23.1 low 47 > 137 yuhao 25.0 0.303601 23.9 low 54 > 138 hucao 85.0 0.339394 23.3 low 64 > 139 hucao 90.0 0.285934 23.1 low 68 > 140 yuhao 27.0 0.327915 23.9 low 62 > 141 hucao 85.0 0.372679 23.9 low 94 > 142 hucao 85.0 0.350147 22.5 low 174 > 143 yuhao 35.0 0.278014 23.7 low 38 > 144 hucao 100.0 0.327273 22.9 low 105 > 145 hucao 68.0 0.309286 24.9 low 105 > 146 hucao 85.0 0.279503 24.3 high 60 > 147 hucao 95.0 0.310870 23.3 high 42 > 148 hucao 95.0 0.309353 24.3 high 64 > 149 hucao 92.0 0.280745 23.5 low 37 > 150 yuhao 25.0 0.300355 24.3 high 107 > 151 yuhao 40.0 0.307692 24.7 high 86 > 152 hucao 40.0 0.273292 25.3 high 72 > 153 hucao 53.0 0.305096 24.7 high 109 > 154 hucao 50.0 0.306288 24.7 high 76 > 155 hucao 95.0 0.312268 22.3 low 60 > 156 hucao 90.0 0.301170 22.7 low 62 > 157 yuhao 38.0 0.305109 22.9 low 68 > 158 hucao 25.0 0.300719 25.3 low 21 > 159 hucao 80.0 0.252149 23.1 low 50 > 160 hucao 90.0 0.290306 23.3 low 63 > 161 hucao 33.0 0.293772 25.1 low 63