Robert Lynch
2013-Oct-06 01:11 UTC
[R] trouble with nlme: Error in MEEM() : Singularity in backsolve at level 0, block 1
I am trying to fit my data, attached, with the following model
CutOff <- 0
fit.full <- lme(fixed= zGrade ~ Rep + ISE +Yfrm7A +Ufrm7A +Female +White
+HSGPA +MATH +AP_TOTAL +Years +Course +
Course*Rep + Course*ISE +Course*Yfrm7A+Course*Ufrm7A
+Course*Female +Course*White +Course*HSGPA +Course*MATH +Course*AP_TOTA
L+Course*Years,
random= ~1|SID,
data = Master.complete[Master.complete$GRADE >= CutOff,])
I get the following error
Error in MEEM(object, conLin, control$niterEM) :
Singularity in backsolve at level 0, block 1
when I take out
+Course*Yfrm7A+Course*Ufrm7A
and just use
fit.full <- lme(fixed= zGrade ~ Rep + ISE +Yfrm7A +Ufrm7A +Female +White
+HSGPA +MATH +AP_TOTAL +Years +Course +
Course*Rep + Course*ISE
+Course*Female+Course*White+Course*HSGPA+Course*MATH+Course*AP_TOTAL+Course*Years,
random= ~1|SID,
data = Master.complete[Master.complete$GRADE >= CutOff,])
I don't get an error
I think this is because when Course == P7A Yfrm7A==Ufrm7A==0. I am not
sure how to work around this. any suggestions would be welcome.
[[alternative HTML version deleted]]
Uwe Ligges
2013-Oct-06 14:44 UTC
[R] trouble with nlme: Error in MEEM() : Singularity in backsolve at level 0, block 1
On 06.10.2013 03:11, Robert Lynch wrote:> I am trying to fit my data, attached, with the following model > > CutOff <- 0 > > fit.full <- lme(fixed= zGrade ~ Rep + ISE +Yfrm7A +Ufrm7A +Female +White > +HSGPA +MATH +AP_TOTAL +Years +Course + > Course*Rep + Course*ISE +Course*Yfrm7A+Course*Ufrm7A > +Course*Female +Course*White +Course*HSGPA +Course*MATH +Course*AP_TOTA > L+Course*Years, > random= ~1|SID, > data = Master.complete[Master.complete$GRADE >= CutOff,]) > I get the following error > Error in MEEM(object, conLin, control$niterEM) : > Singularity in backsolve at level 0, block 1 > > > when I take out > +Course*Yfrm7A+Course*Ufrm7A > and just use > fit.full <- lme(fixed= zGrade ~ Rep + ISE +Yfrm7A +Ufrm7A +Female +White > +HSGPA +MATH +AP_TOTAL +Years +Course + > Course*Rep + Course*ISE > +Course*Female+Course*White+Course*HSGPA+Course*MATH+Course*AP_TOTAL+Course*Years, > random= ~1|SID, > data = Master.complete[Master.complete$GRADE >= CutOff,]) > I don't get an error > > I think this is because when Course == P7A Yfrm7A==Ufrm7A==0.Hmmmm, actually it does not make sense to include constant variables in your model. Please talk to your supervisor, this i not a problem with R but about understanding the model. Best, Uwe Ligges > I am not> sure how to work around this. any suggestions would be welcome. > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. >