Re: [R] computationally singular error with mice()

2011-11-26 Thread Fei
Hi Josh, You opened the blackbox up to me. Now I know what is the right way to go. Thank you so much! Best, Fei -- View this message in context: http://r.789695.n4.nabble.com/computationally-singular-error-with-mice-tp4109583p4111537.html Sent from the R help mailing list archive at Nabble.com.

Re: [R] computationally singular error with mice()

2011-11-26 Thread Joshua Wiley
Hi Fei, On Sat, Nov 26, 2011 at 9:07 AM, Fei wrote: > Hi Josh, > > Thanks for the kind reminder of posting the dataframe on. My dataframe > contains lots of categorical variables, which seems to be problematic.  For > instance, > > dob        status         edu               mrext >      mar

Re: [R] computationally singular error with mice()

2011-11-26 Thread Fei
Hi Weidong, Thank you for the clear explanation. You are right it is not the categorical variables that are causing the trouble. It might be the relatively small number of sample that causing the problem given so many variables. I tried to exclude some variables that are not essential to all the a

Re: [R] computationally singular error with mice()

2011-11-26 Thread Weidong Gu
Hi Fei, I wouldn't worry to much about categorical variables for mice. Mice would use logisitic regression for binary and polytomous logistic regression for categorical variables with >2 levels. However, you should not include factors with a lot of levels, saying>30, in imputation models because i

Re: [R] computationally singular error with mice()

2011-11-26 Thread Fei
Hi Josh, Thanks for the kind reminder of posting the dataframe on. My dataframe contains lots of categorical variables, which seems to be problematic. For instance, dobstatus edu mrext married highschool yes, full time Do you know how to specify t

Re: [R] computationally singular error with mice()

2011-11-25 Thread Joshua Wiley
Hi Fei, On Fri, Nov 25, 2011 at 7:20 PM, Fei wrote: >> imp<-mice(mydataframe, seed=1) > When trying the above command, I got the error term: > >  iter imp variable >  1   1  medu > Error in solve.default(xtx + diag(pen)) : >  system is computationally singular: reciprocal condition number = > 1.1

[R] computationally singular error with mice()

2011-11-25 Thread Fei
> imp<-mice(mydataframe, seed=1) When trying the above command, I got the error term: iter imp variable 1 1 medu Error in solve.default(xtx + diag(pen)) : system is computationally singular: reciprocal condition number = 1.16487e-025/ What does that mean? How can I address this issue? My