[R] nlme Singularity in backsolve at level 0, block 1

From: Elizabeth Lawson <lizzylaws_at_yahoo.com>
Date: Thu 20 Oct 2005 - 01:27:06 EST


Hi,  

I am hoping some one can help with this.  

I am using nlme to fit a random coefficients model. It ran for hours before returning  

Error: Singularity in backsolve at level 0, block 1

The model is
> plavix.nlme<-nlme(PLX_NRX~loglike(PLX_NRX,PD4_42D,GAT_34D,VIS_42D,MSL_42D,SPE_ROL,XM2_DUM,THX_DUM,b0,b1,b2,b3,b4,b5,b6,b7,alpha),

+ data=data,
+ fixed=list(b0 + b1+b2+b3+b4+b5+b6+b7+alpha~1),
+ random=b0+b1+b2+b3+b4+b5+b6+b7~1|menum,
+ 
+ start=c(b0=0,b1=0,b2=0,b3=0,b4=0,b5=0,b6=0,b7=0,alpha=5)
+ )

Can anyone tell me what this error means and how I can run the model?  

Thanks,  

Elizabeth Lawson                 


        [[alternative HTML version deleted]]



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Oct 20 01:39:18 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:40:46 EST