[R] Problems with lm()

Hsin-Ya Lee leeznar at yahoo.com.tw
Sat Jun 21 08:18:31 CEST 2008


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
>> 
>> 
>> 
>> 
>>      
>> ______________________________________________________________________________________________________
>> [[elided Yahoo spam]]
>> Content-Type: application/msword; name="Result_SPSS.doc"
>> Content-Transfer-Encoding: base64
>> Content-Description: 3367377201-Result_SPSS.doc
>> Content-Disposition: attachment; filename="Result_SPSS.doc"
>> 
>> AAAAAAAAAAAA
>> 
> 
>> ______________________________________________
>> 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.
> 
> 

-- 
View this message in context: http://www.nabble.com/Problems-with-lm%28%29-tp17999900p18041445.html
Sent from the R help mailing list archive at Nabble.com.



More information about the R-help mailing list