Why does the S:x1 column disappear (presumably S:x1 goes into ID but I dont
know why)? S is a factor, x1 is a covariate and ID is a factor.
rich.side<-aov(y~S*x1+ID)
summary(rich.side)
Below is the model frame
model.frame(~S*x1+ID)
S x1 ID
1 1 12 A
2 1 12 A
3 1 12 A
4 1 12 A
5 1 0 B
6 1 0 B
7 1 0 B
8 1 0 B
9 1 0 C
10 1 0 C
11 1 0 C
12 1 0 C
13 1 0 D
14 1 0 D
15 1 0 D
16 1 0 D
17 1 0 E
18 1 0 E
19 1 0 E
20 1 0 E
21 1 0 F
22 1 0 F
23 1 0 F
24 1 0 F
25 2 6 AB
26 2 6 AB
27 2 6 AB
28 2 6 AB
29 2 6 AC
30 2 6 AC
31 2 6 AC
32 2 6 AC
33 2 6 AD
34 2 6 AD
35 2 6 AD
36 2 6 AD
37 2 6 AE
38 2 6 AE
39 2 6 AE
40 2 6 AE
41 2 6 AF
42 2 6 AF
43 2 6 AF
44 2 6 AF
45 2 0 BC
46 2 0 BC
47 2 0 BC
48 2 0 BC
49 2 0 BD
50 2 0 BD
51 2 0 BD
52 2 0 BD
53 2 0 BE
54 2 0 BE
55 2 0 BE
56 2 0 BE
57 2 0 BF
58 2 0 BF
59 2 0 BF
60 2 0 BF
61 2 0 CD
62 2 0 CD
63 2 0 CD
64 2 0 CD
65 2 0 CE
66 2 0 CE
67 2 0 CE
68 2 0 CE
69 2 0 CF
70 2 0 CF
71 2 0 CF
72 2 0 CF
73 2 0 DE
74 2 0 DE
75 2 0 DE
76 2 0 DE
77 2 0 DF
78 2 0 DF
79 2 0 DF
80 2 0 DF
81 2 0 EF
82 2 0 EF
83 2 0 EF
84 2 0 EF
85 3 4 ABC
86 3 4 ABC
87 3 4 ABC
88 3 4 ABC
89 3 4 ABD
90 3 4 ABD
91 3 4 ABD
92 3 4 ABD
93 3 4 ABE
94 3 4 ABE
95 3 4 ABE
96 3 4 ABE
97 3 4 ABF
98 3 4 ABF
99 3 4 ABF
100 3 4 ABF
101 3 4 ACD
102 3 4 ACD
103 3 4 ACD
104 3 4 ACD
105 3 4 ACE
106 3 4 ACE
107 3 4 ACE
108 3 4 ACE
109 3 4 ACF
110 3 4 ACF
111 3 4 ACF
112 3 4 ACF
113 3 4 ADE
114 3 4 ADE
115 3 4 ADE
116 3 4 ADE
117 3 4 ADF
118 3 4 ADF
119 3 4 ADF
120 3 4 ADF
121 3 4 AEF
122 3 4 AEF
123 3 4 AEF
124 3 4 AEF
125 3 0 BCD
126 3 0 BCD
127 3 0 BCD
128 3 0 BCD
129 3 0 BCE
130 3 0 BCE
131 3 0 BCE
132 3 0 BCE
133 3 0 BCF
134 3 0 BCF
135 3 0 BCF
136 3 0 BCF
137 3 0 BDE
138 3 0 BDE
139 3 0 BDE
140 3 0 BDE
141 3 0 BDF
142 3 0 BDF
143 3 0 BDF
144 3 0 BDF
145 3 0 BEF
146 3 0 BEF
147 3 0 BEF
148 3 0 BEF
149 3 0 CDE
150 3 0 CDE
151 3 0 CDE
152 3 0 CDE
153 3 0 CDF
154 3 0 CDF
155 3 0 CDF
156 3 0 CDF
157 3 0 CEF
158 3 0 CEF
159 3 0 CEF
160 3 0 CEF
161 3 0 DEF
162 3 0 DEF
163 3 0 DEF
164 3 0 DEF
--
Yours sincerely,
Justin
*I check my email at 9AM and 4PM everyday*
*If you have an EMERGENCY, contact me at +447938674419(UK) or
+60125056192(Malaysia)*
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Presumably it disappears because there is a unique value of ID for eac combination of S*x1 so they are indistinguishable. On 19/07/2016 12:53, Justin Thong wrote:> Why does the S:x1 column disappear (presumably S:x1 goes into ID but I dont > know why)? S is a factor, x1 is a covariate and ID is a factor. > > rich.side<-aov(y~S*x1+ID) > summary(rich.side) > > Below is the model frame > > model.frame(~S*x1+ID) > > S x1 ID > 1 1 12 A > 2 1 12 A > 3 1 12 A > 4 1 12 A > 5 1 0 B > 6 1 0 B > 7 1 0 B > 8 1 0 B > 9 1 0 C > 10 1 0 C > 11 1 0 C > 12 1 0 C > 13 1 0 D > 14 1 0 D > 15 1 0 D > 16 1 0 D > 17 1 0 E > 18 1 0 E > 19 1 0 E > 20 1 0 E > 21 1 0 F > 22 1 0 F > 23 1 0 F > 24 1 0 F > 25 2 6 AB > 26 2 6 AB > 27 2 6 AB > 28 2 6 AB > 29 2 6 AC > 30 2 6 AC > 31 2 6 AC > 32 2 6 AC > 33 2 6 AD > 34 2 6 AD > 35 2 6 AD > 36 2 6 AD > 37 2 6 AE > 38 2 6 AE > 39 2 6 AE > 40 2 6 AE > 41 2 6 AF > 42 2 6 AF > 43 2 6 AF > 44 2 6 AF > 45 2 0 BC > 46 2 0 BC > 47 2 0 BC > 48 2 0 BC > 49 2 0 BD > 50 2 0 BD > 51 2 0 BD > 52 2 0 BD > 53 2 0 BE > 54 2 0 BE > 55 2 0 BE > 56 2 0 BE > 57 2 0 BF > 58 2 0 BF > 59 2 0 BF > 60 2 0 BF > 61 2 0 CD > 62 2 0 CD > 63 2 0 CD > 64 2 0 CD > 65 2 0 CE > 66 2 0 CE > 67 2 0 CE > 68 2 0 CE > 69 2 0 CF > 70 2 0 CF > 71 2 0 CF > 72 2 0 CF > 73 2 0 DE > 74 2 0 DE > 75 2 0 DE > 76 2 0 DE > 77 2 0 DF > 78 2 0 DF > 79 2 0 DF > 80 2 0 DF > 81 2 0 EF > 82 2 0 EF > 83 2 0 EF > 84 2 0 EF > 85 3 4 ABC > 86 3 4 ABC > 87 3 4 ABC > 88 3 4 ABC > 89 3 4 ABD > 90 3 4 ABD > 91 3 4 ABD > 92 3 4 ABD > 93 3 4 ABE > 94 3 4 ABE > 95 3 4 ABE > 96 3 4 ABE > 97 3 4 ABF > 98 3 4 ABF > 99 3 4 ABF > 100 3 4 ABF > 101 3 4 ACD > 102 3 4 ACD > 103 3 4 ACD > 104 3 4 ACD > 105 3 4 ACE > 106 3 4 ACE > 107 3 4 ACE > 108 3 4 ACE > 109 3 4 ACF > 110 3 4 ACF > 111 3 4 ACF > 112 3 4 ACF > 113 3 4 ADE > 114 3 4 ADE > 115 3 4 ADE > 116 3 4 ADE > 117 3 4 ADF > 118 3 4 ADF > 119 3 4 ADF > 120 3 4 ADF > 121 3 4 AEF > 122 3 4 AEF > 123 3 4 AEF > 124 3 4 AEF > 125 3 0 BCD > 126 3 0 BCD > 127 3 0 BCD > 128 3 0 BCD > 129 3 0 BCE > 130 3 0 BCE > 131 3 0 BCE > 132 3 0 BCE > 133 3 0 BCF > 134 3 0 BCF > 135 3 0 BCF > 136 3 0 BCF > 137 3 0 BDE > 138 3 0 BDE > 139 3 0 BDE > 140 3 0 BDE > 141 3 0 BDF > 142 3 0 BDF > 143 3 0 BDF > 144 3 0 BDF > 145 3 0 BEF > 146 3 0 BEF > 147 3 0 BEF > 148 3 0 BEF > 149 3 0 CDE > 150 3 0 CDE > 151 3 0 CDE > 152 3 0 CDE > 153 3 0 CDF > 154 3 0 CDF > 155 3 0 CDF > 156 3 0 CDF > 157 3 0 CEF > 158 3 0 CEF > 159 3 0 CEF > 160 3 0 CEF > 161 3 0 DEF > 162 3 0 DEF > 163 3 0 DEF > 164 3 0 DEF >-- Michael http://www.dewey.myzen.co.uk/home.html
Hi Michael,
Thank you for the reply.
I am sorry I forgot to print out the anova table to make my question clear.
Df Sum Sq Mean Sq F value Pr(>F)
S 2 0.000019 9.630e-06 0.818 0.444
x1 1 0.000256 2.560e-04 21.751 9.44e-06 ***
ID 47 0.003524 7.498e-05 6.370 3.35e-15 ***
Resid 102 0.001201 1.177e-05
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
There is *no* unique value for ID for each combination of S and x1. For
example, S=1 and x1=0 can equal to either B or C or D or E or F .
Perhaps you mean that for each combination of S and x1 have different
values. If that is the case, I think maybe it makes sense.
*What I think? *
Anova has this thing where it fits the terms of 1st order first ( a formula
term including no interactions) before it fits a 2nd order term ( a formula
term including 1 interaction) and so on.
First Order--> Second Order--> Third Order--> etc
Therefore, it is known that the true fitting formula is not S+x1+S:x1+ID
but it is S+x1+ID+S:x1. Hence, it appears that ID is fitted before S:x1 but
since ID is a more refined factor than S:x1, it can be said that S:x1 is
already included in the fit of ID so R recognizes the linear dependance and
excludes the term S:x1.
In other words, S:x1 is linearly dependant to ID. And so, the row S:x1
disappears because it is considered within ID.
Does this makes sense?
On 19 July 2016 at 16:19, Michael Dewey <lists at dewey.myzen.co.uk>
wrote:
> Presumably it disappears because there is a unique value of ID for eac
> combination of S*x1 so they are indistinguishable.
>
>
> On 19/07/2016 12:53, Justin Thong wrote:
>
>> Why does the S:x1 column disappear (presumably S:x1 goes into ID but I
>> dont
>> know why)? S is a factor, x1 is a covariate and ID is a factor.
>>
>> rich.side<-aov(y~S*x1+ID)
>> summary(rich.side)
>>
>> Below is the model frame
>>
>> model.frame(~S*x1+ID)
>>
>> S x1 ID
>> 1 1 12 A
>> 2 1 12 A
>> 3 1 12 A
>> 4 1 12 A
>> 5 1 0 B
>> 6 1 0 B
>> 7 1 0 B
>> 8 1 0 B
>> 9 1 0 C
>> 10 1 0 C
>> 11 1 0 C
>> 12 1 0 C
>> 13 1 0 D
>> 14 1 0 D
>> 15 1 0 D
>> 16 1 0 D
>> 17 1 0 E
>> 18 1 0 E
>> 19 1 0 E
>> 20 1 0 E
>> 21 1 0 F
>> 22 1 0 F
>> 23 1 0 F
>> 24 1 0 F
>> 25 2 6 AB
>> 26 2 6 AB
>> 27 2 6 AB
>> 28 2 6 AB
>> 29 2 6 AC
>> 30 2 6 AC
>> 31 2 6 AC
>> 32 2 6 AC
>> 33 2 6 AD
>> 34 2 6 AD
>> 35 2 6 AD
>> 36 2 6 AD
>> 37 2 6 AE
>> 38 2 6 AE
>> 39 2 6 AE
>> 40 2 6 AE
>> 41 2 6 AF
>> 42 2 6 AF
>> 43 2 6 AF
>> 44 2 6 AF
>> 45 2 0 BC
>> 46 2 0 BC
>> 47 2 0 BC
>> 48 2 0 BC
>> 49 2 0 BD
>> 50 2 0 BD
>> 51 2 0 BD
>> 52 2 0 BD
>> 53 2 0 BE
>> 54 2 0 BE
>> 55 2 0 BE
>> 56 2 0 BE
>> 57 2 0 BF
>> 58 2 0 BF
>> 59 2 0 BF
>> 60 2 0 BF
>> 61 2 0 CD
>> 62 2 0 CD
>> 63 2 0 CD
>> 64 2 0 CD
>> 65 2 0 CE
>> 66 2 0 CE
>> 67 2 0 CE
>> 68 2 0 CE
>> 69 2 0 CF
>> 70 2 0 CF
>> 71 2 0 CF
>> 72 2 0 CF
>> 73 2 0 DE
>> 74 2 0 DE
>> 75 2 0 DE
>> 76 2 0 DE
>> 77 2 0 DF
>> 78 2 0 DF
>> 79 2 0 DF
>> 80 2 0 DF
>> 81 2 0 EF
>> 82 2 0 EF
>> 83 2 0 EF
>> 84 2 0 EF
>> 85 3 4 ABC
>> 86 3 4 ABC
>> 87 3 4 ABC
>> 88 3 4 ABC
>> 89 3 4 ABD
>> 90 3 4 ABD
>> 91 3 4 ABD
>> 92 3 4 ABD
>> 93 3 4 ABE
>> 94 3 4 ABE
>> 95 3 4 ABE
>> 96 3 4 ABE
>> 97 3 4 ABF
>> 98 3 4 ABF
>> 99 3 4 ABF
>> 100 3 4 ABF
>> 101 3 4 ACD
>> 102 3 4 ACD
>> 103 3 4 ACD
>> 104 3 4 ACD
>> 105 3 4 ACE
>> 106 3 4 ACE
>> 107 3 4 ACE
>> 108 3 4 ACE
>> 109 3 4 ACF
>> 110 3 4 ACF
>> 111 3 4 ACF
>> 112 3 4 ACF
>> 113 3 4 ADE
>> 114 3 4 ADE
>> 115 3 4 ADE
>> 116 3 4 ADE
>> 117 3 4 ADF
>> 118 3 4 ADF
>> 119 3 4 ADF
>> 120 3 4 ADF
>> 121 3 4 AEF
>> 122 3 4 AEF
>> 123 3 4 AEF
>> 124 3 4 AEF
>> 125 3 0 BCD
>> 126 3 0 BCD
>> 127 3 0 BCD
>> 128 3 0 BCD
>> 129 3 0 BCE
>> 130 3 0 BCE
>> 131 3 0 BCE
>> 132 3 0 BCE
>> 133 3 0 BCF
>> 134 3 0 BCF
>> 135 3 0 BCF
>> 136 3 0 BCF
>> 137 3 0 BDE
>> 138 3 0 BDE
>> 139 3 0 BDE
>> 140 3 0 BDE
>> 141 3 0 BDF
>> 142 3 0 BDF
>> 143 3 0 BDF
>> 144 3 0 BDF
>> 145 3 0 BEF
>> 146 3 0 BEF
>> 147 3 0 BEF
>> 148 3 0 BEF
>> 149 3 0 CDE
>> 150 3 0 CDE
>> 151 3 0 CDE
>> 152 3 0 CDE
>> 153 3 0 CDF
>> 154 3 0 CDF
>> 155 3 0 CDF
>> 156 3 0 CDF
>> 157 3 0 CEF
>> 158 3 0 CEF
>> 159 3 0 CEF
>> 160 3 0 CEF
>> 161 3 0 DEF
>> 162 3 0 DEF
>> 163 3 0 DEF
>> 164 3 0 DEF
>>
>>
> --
> Michael
> http://www.dewey.myzen.co.uk/home.html
>
--
Yours sincerely,
Justin
*I check my email at 9AM and 4PM everyday*
*If you have an EMERGENCY, contact me at +447938674419(UK) or
+60125056192(Malaysia)*
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