[R] Problems with lm()

Dr. Christoph Scherber Christoph.Scherber at agr.uni-goettingen.de
Sat Jun 21 09:12:23 CEST 2008


Dear Hsin-Ya,

Then it might be that you have checked "Type 3 sums of squares" in SPSS,
while R uses type 1 by default.

>
> Dear Dr. Andrew Robinson:
>
> Thanks for your reply.  In my data, subject is nested within sequence.
> According to Dr. Christoph's reply, I have change the sequence data.
> It seems not work in R.  However, I am sure that I run the same data with
> GLM in SPSS that I posted in first time.  I really do not know where the
> problem is.  How can I do?
>
> Best regards,
> Hsin-Ya
>
>
>
>
>
> Andrew Robinson-6 wrote:
>>
>> In your data, subject is nested within sequence.  Was that your
>> intention?
>>
>>> a<-c(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14)
>>> b<-c(1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2)
>>> c<-c(2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2)
>>> d<-c(2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1)
>>> e<-c(1739,1633,1481,1837,1780,2073,1374,1629,1555,1385,1756,1522,1566,1643,
>> + 1939,1615,1475,1759,1388,1483,1127,1682,1542,1247,1235,1605,1598,1718
>> + )
>>> Data<-data.frame(subject=as.factor(a),
>> + drug=as.factor(b), period=as.factor(c),
>> + sequence=as.factor(d), Max=e)
>>> Data
>>    subject drug period sequence  Max
>> 1        1    1      2        2 1739
>> 2        1    2      1        2 1633
>> 3        2    1      1        1 1481
>> 4        2    2      2        1 1837
>> 5        3    1      2        2 1780
>> 6        3    2      1        2 2073
>> 7        4    1      1        1 1374
>> 8        4    2      2        1 1629
>> 9        5    1      2        2 1555
>> 10       5    2      1        2 1385
>> 11       6    1      1        1 1756
>> 12       6    2      2        1 1522
>> 13       7    1      2        2 1566
>> 14       7    2      1        2 1643
>> 15       8    1      1        1 1939
>> 16       8    2      2        1 1615
>> 17       9    1      2        2 1475
>> 18       9    2      1        2 1759
>> 19      10    1      1        1 1388
>> 20      10    2      2        1 1483
>> 21      11    1      2        2 1127
>> 22      11    2      1        2 1682
>> 23      12    1      1        1 1542
>> 24      12    2      2        1 1247
>> 25      13    1      2        2 1235
>> 26      13    2      1        2 1605
>> 27      14    1      1        1 1598
>> 28      14    2      2        1 1718
>>
>>
>>
>> Andrew
>>
>>
>> On Thu, Jun 19, 2008 at 04:29:16PM +0800, leeznar wrote:
>>> Dear R-users:
>>>
>>> I am a new R-user and I have a question about lm
>>> function.  Here is my data.
>>> a<-c(1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13,14,14)
>>> b<-c(1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2)
>>> c<-c(2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2)
>>> d<-c(2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1,2,2,1,1)
>>> e<-c(1739,1633,1481,1837,1780,2073,1374,1629,1555,1385,1756,1522,1566,1643,1939,1615,1475,1759,1388,1483,1127,1682,1542,1247,1235,1605,1598,1718
>>> )
>>> Data<-data.frame(subject=as.factor(a),
>>> drug=as.factor(b), period=as.factor(c),
>>> sequence=as.factor(d), Max=e)
>>>
>>> lm3<- lm(Max ~subject*sequence + sequence + period +
>>> drug, data=Data)
>>> print(lm3)
>>> anova(lm3)
>>>
>>> When I use lm to fit the data, there are some problems
>>> in ??subject*sequence??.   I have use GLM in SPSS to
>>> fit the same data, and it seems there is no problem.
>>>
>>> I don??t know where my problem is.  How can I get the
>>> same result with SPSS? How can I do?
>>>
>>> Best regards,
>>> Hsin-Ya Lee
>>>
>>>
>>>
>>>
>>>
>>> ______________________________________________________________________________________________________
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>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>> --
>> Andrew Robinson
>> Department of Mathematics and Statistics            Tel: +61-3-8344-6410
>> University of Melbourne, VIC 3010 Australia         Fax: +61-3-8344-4599
>> http://www.ms.unimelb.edu.au/~andrewpr
>> http://blogs.mbs.edu/fishing-in-the-bay/
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
> --
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>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



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