Hello I have some test data that looks like that from a within subject experiment. Subject Task-Kind Data-Kind Time-Taken Correct 1 A Data1 5 1 1 A Data1 3 0 1 A Data1 1 1 1 A Data2 8 1 1 A Data2 7 0 1 A Data2 5 0 1 A Data3 2 1 1 A Data3 7 0 1 A Data3 5 0 1 A Data3 6 0 1 B Data1 3 1 1 B Data1 1 1 1 B Data1 3 0 1 B Data2 9 0 1 B Data2 8 1 1 B Data2 5 0 1 B Data3 2 1 1 B Data3 7 2 1 B Data3 5 3 1 B Data3 6 0 1 C Data1 3 1 1 C Data1 1 1 1 C Data1 3 0 1 C Data2 9 0 1 C Data2 8 1 1 C Data2 5 0 1 C Data3 2 1 1 C Data3 7 2 1 C Data3 5 3 1 C Data3 6 0 2 A Data1 5 1 2 A Data1 3 0 2 A Data1 1 1 2 A Data2 8 1 2 A Data2 7 0 2 A Data2 5 0 2 A Data3 2 1 2 A Data3 7 0 2 A Data3 5 0 2 A Data3 6 0 2 B Data1 3 1 2 B Data1 1 1 2 B Data1 3 0 2 B Data2 9 0 2 B Data2 8 1 2 B Data2 5 0 2 B Data3 2 1 2 B Data3 7 2 2 B Data3 5 3 2 B Data3 6 0 2 C Data1 3 1 2 C Data1 1 1 2 C Data1 3 0 2 C Data2 9 0 2 C Data2 8 1 2 C Data2 5 0 2 C Data3 2 1 2 C Data3 7 2 2 C Data3 5 3 2 C Data3 6 0 . . . some notes: there are 20 subjects there are 5 different kinds of tasks There are 5 different kinds of data and there are several different variations for a certain kind of task and kind of data which is why for Subject = 1 Task-Kind=A and Data-Kind=Data1 we have 3 different results. The measured parameters are time to complete the task and whether it was correct or not (0 implies correct and 1 implies not correct) I am computing the anova as follows: aov.ex = aov(Correct~Task-Kind*Data-Kind+Error(Subject/(Task-Kind*Data-Kind)),data=allDataRaw.xp) since I want to see how the result is affected by the different kinds of data as well as the the kind of task and I get a warning message saying: Error() model is singular I would be very grateful if someone could please tell me what does this mean. Thanks Pascal -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103.html Sent from the R help mailing list archive at Nabble.com.
Error() model is singular - what does that mean
8 messages · zetwal, Jessica Streicher, Bert Gunter +1 more
Just looking at it i would try renaming Task-Kind, Data-Kind an Time-Taken Those are ambiguous in the Formula. "Task-Kind" vs "Task" - "Kind" Though that might not be the error at hand :)
On 02.07.2012, at 14:15, zetwal wrote:
Hello I have some test data that looks like that from a within subject experiment. Subject Task-Kind Data-Kind Time-Taken Correct 1 A Data1 5 1 1 A Data1 3 0 1 A Data1 1 1 1 A Data2 8 1 1 A Data2 7 0 1 A Data2 5 0 1 A Data3 2 1 1 A Data3 7 0 1 A Data3 5 0 1 A Data3 6 0 1 B Data1 3 1 1 B Data1 1 1 1 B Data1 3 0 1 B Data2 9 0 1 B Data2 8 1 1 B Data2 5 0 1 B Data3 2 1 1 B Data3 7 2 1 B Data3 5 3 1 B Data3 6 0 1 C Data1 3 1 1 C Data1 1 1 1 C Data1 3 0 1 C Data2 9 0 1 C Data2 8 1 1 C Data2 5 0 1 C Data3 2 1 1 C Data3 7 2 1 C Data3 5 3 1 C Data3 6 0 2 A Data1 5 1 2 A Data1 3 0 2 A Data1 1 1 2 A Data2 8 1 2 A Data2 7 0 2 A Data2 5 0 2 A Data3 2 1 2 A Data3 7 0 2 A Data3 5 0 2 A Data3 6 0 2 B Data1 3 1 2 B Data1 1 1 2 B Data1 3 0 2 B Data2 9 0 2 B Data2 8 1 2 B Data2 5 0 2 B Data3 2 1 2 B Data3 7 2 2 B Data3 5 3 2 B Data3 6 0 2 C Data1 3 1 2 C Data1 1 1 2 C Data1 3 0 2 C Data2 9 0 2 C Data2 8 1 2 C Data2 5 0 2 C Data3 2 1 2 C Data3 7 2 2 C Data3 5 3 2 C Data3 6 0 . . . some notes: there are 20 subjects there are 5 different kinds of tasks There are 5 different kinds of data and there are several different variations for a certain kind of task and kind of data which is why for Subject = 1 Task-Kind=A and Data-Kind=Data1 we have 3 different results. The measured parameters are time to complete the task and whether it was correct or not (0 implies correct and 1 implies not correct) I am computing the anova as follows: aov.ex = aov(Correct~Task-Kind*Data-Kind+Error(Subject/(Task-Kind*Data-Kind)),data=allDataRaw.xp) since I want to see how the result is affected by the different kinds of data as well as the the kind of task and I get a warning message saying: Error() model is singular I would be very grateful if someone could please tell me what does this mean. Thanks Pascal -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ 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.
Also, try googling for - R model is singular - , there seem to have been a lot of people with that particular error.
On 02.07.2012, at 14:56, Jessica Streicher wrote:
Just looking at it i would try renaming Task-Kind, Data-Kind an Time-Taken Those are ambiguous in the Formula. "Task-Kind" vs "Task" - "Kind" Though that might not be the error at hand :) On 02.07.2012, at 14:15, zetwal wrote:
Hello I have some test data that looks like that from a within subject experiment. Subject Task-Kind Data-Kind Time-Taken Correct 1 A Data1 5 1 1 A Data1 3 0 1 A Data1 1 1 1 A Data2 8 1 1 A Data2 7 0 1 A Data2 5 0 1 A Data3 2 1 1 A Data3 7 0 1 A Data3 5 0 1 A Data3 6 0 1 B Data1 3 1 1 B Data1 1 1 1 B Data1 3 0 1 B Data2 9 0 1 B Data2 8 1 1 B Data2 5 0 1 B Data3 2 1 1 B Data3 7 2 1 B Data3 5 3 1 B Data3 6 0 1 C Data1 3 1 1 C Data1 1 1 1 C Data1 3 0 1 C Data2 9 0 1 C Data2 8 1 1 C Data2 5 0 1 C Data3 2 1 1 C Data3 7 2 1 C Data3 5 3 1 C Data3 6 0 2 A Data1 5 1 2 A Data1 3 0 2 A Data1 1 1 2 A Data2 8 1 2 A Data2 7 0 2 A Data2 5 0 2 A Data3 2 1 2 A Data3 7 0 2 A Data3 5 0 2 A Data3 6 0 2 B Data1 3 1 2 B Data1 1 1 2 B Data1 3 0 2 B Data2 9 0 2 B Data2 8 1 2 B Data2 5 0 2 B Data3 2 1 2 B Data3 7 2 2 B Data3 5 3 2 B Data3 6 0 2 C Data1 3 1 2 C Data1 1 1 2 C Data1 3 0 2 C Data2 9 0 2 C Data2 8 1 2 C Data2 5 0 2 C Data3 2 1 2 C Data3 7 2 2 C Data3 5 3 2 C Data3 6 0 . . . some notes: there are 20 subjects there are 5 different kinds of tasks There are 5 different kinds of data and there are several different variations for a certain kind of task and kind of data which is why for Subject = 1 Task-Kind=A and Data-Kind=Data1 we have 3 different results. The measured parameters are time to complete the task and whether it was correct or not (0 implies correct and 1 implies not correct) I am computing the anova as follows: aov.ex = aov(Correct~Task-Kind*Data-Kind+Error(Subject/(Task-Kind*Data-Kind)),data=allDataRaw.xp) since I want to see how the result is affected by the different kinds of data as well as the the kind of task and I get a warning message saying: Error() model is singular I would be very grateful if someone could please tell me what does this mean. Thanks Pascal -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103.html Sent from the R help mailing list archive at Nabble.com.
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Hi Jessica Thanks for the replies. I was getting a bit confused at the answers when I googled for it. So I thought maybe it would be better if I present my specific test case (could be i'm doing something very wrong as I am quite new to this thing) Also, there are no dashes in my real names, I only have Data and Task for example. I've changed the names just to make the labels more meaningful when I was posting. -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103p4635178.html Sent from the R help mailing list archive at Nabble.com.
On changing the parameters; using only Error(User), I don't get any warning on singularity. However most tutorials I saw seemed to point to using Error(User/(whatever i specified before)) Are there some rules which indicated when I should use only Error(User) and Error(User/(...)) Thanks Pascal -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103p4635181.html Sent from the R help mailing list archive at Nabble.com.
On Jul 2, 2012, at 20:02 , zetwal wrote:
On changing the parameters; using only Error(User), I don't get any warning on singularity. However most tutorials I saw seemed to point to using Error(User/(whatever i specified before)) Are there some rules which indicated when I should use only Error(User) and Error(User/(...))
Not really, but if you don't have a completely balanced User*A*B design, then aov() likely gets in trouble. If I understand your original message correctly, you have 9 observations per subject but 5 levels of the within-subject factors, so that with N subjects you have 9N observations but the error model tries to fit 25N parameters and this is what triggers the error message. With just the Error(User) term, the model has just N parameters and things are fine, although I suppose you get the A*B effects tested in both strata.
Thanks Pascal -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103p4635181.html Sent from the R help mailing list archive at Nabble.com.
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Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com
That I correct. I have only 9. Thanks for the explanation :) -- View this message in context: http://r.789695.n4.nabble.com/Error-model-is-singular-what-does-that-mean-tp4635103p4635263.html Sent from the R help mailing list archive at Nabble.com.