To Whom It May Concern: Thanks in advance for any assistance. I am trying to fit a linear mixed effects model to a reliability degradation data set for a light emitting diode (the dependent variable is the normalized output power, and the there are two independent variables: the age of each device and the forward injection current). I have linearized the model by taking logarithms of the independent and dependent variables. There are 48 individual UNITS that are allocated two three different CURRENT values. For each UNIT there is an NPOWER reading at various TIMEs. The total number of observations is 332. I have had no problem fitting models of the form, Log(NPOWER) ~ log(TIME) + log(CURRENT), ..., random = ~ 1 + log(TIME) | UNIT (where UNIT is the grouping variable) I get into trouble when I try to add a random effect for log(CURRENT). When I try to fit this model my PC runs for several minutes and then issues a warning that the application has performed an illegal operation. I have included the fault information at the end of this message. I would be very grateful for any hints. I have tried allocating more memory ( --vsize 30M) to no avail. I do not know what is going on. Here are some specifics about my version of the software and hardware:
version
_ platform Windows arch x86 os Win32 system x86, Win32 status Beta status.rev 0 major 0 minor 63.3 year 1999 month March day 6 language R I am using the version of lme that is in the CRAN contributed binaries folder for WIN95/NT Package: lme Version: 2.9-4 I am using an IBM ThinkPad 600. I would really like to have someone try my troublesome model with my data on a UNIX box to see if this is a PC-specific problem. If someone can help, I would be glad to email the data set. Regards, David Erhart Vivid Semiconductor Derhart at vividsemi.com Fault Information: RGUI caused an invalid page fault in module CRTDLL.DLL at 016f:7fd21519. Registers: EAX=00000000 CS=016f EIP=7fd21519 EFLGS=00010202 EBX=0253dd68 SS=0177 ESP=0253daf0 EBP=0253dd50 ECX=00000053 DS=0177 ESI=00000053 FS=0fe7 EDX=0253dd68 ES=0177 EDI=00000053 GS=0000 Bytes at CS:EIP: 88 08 8b 0a 0f b6 01 41 89 0a eb 0d 52 ff 74 24 Stack dump: 7fd20e08 00000053 0253dd68 0253dd38 00000003 00000000 00000000 0253df48 0000000c 0253dd84 0253dd54 02634bbc 0253df48 0394fc8c 02634bbc 0253df48 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._