Displaying 1 result from an estimated 1 matches for "lbrna".
2004 Sep 22
1
impenetrable warning
Dear R-help,
Can anyone explain the meaning of the warning,
Singular precision matrix in level -1, block 1
? Or how to track down where it comes from?
More precisely, using the nlme package, I'm issued with the warning
itt2 <- lme(lrna~rx.nrti+lbrna, random=~1|patid,
cor=corExp(form=~days|patid,nugget=T), weights=varPower(
form=~lbrna),data=rna3)
Warning messages:
1: Singular precision matrix in level -1, block 1
2: Singular precision matrix in level -1, block 1
the output is:
Linear mixed-effects model fit by REML
Data: rna3
Log-restric...