Displaying 7 results from an estimated 7 matches for "napattern".
Did you mean:
mypattern
2005 Jul 07
2
Problems with nlme: Quinidine example
...val, lV,
lKa, lCl),
+ data=Quinidine,
+ fixed=lV + lKa + lCl ~ 1,
+ random=pdDiag(lV + lCl ~ 1),
+ groups= ~ Subject,
+ start=list(fixed=c(5, -0.3, 2)),
+ na.action=na.pass, naPattern= ~ !is.na(conc))
Error in solve.default(estimates[dimE[1] - (p:1), dimE[2] - (p:1), drop =
FALSE]) :
system is computationally singular: reciprocal condition number =
6.61723e-17
Note:
- I am running R version 2.1.0 on Linux.
- The only difference between the code in the book and the cod...
2003 May 12
1
plot.ranef.lme (PR#2986)
library(nlme)
data(Phenobarb)
na.include <- function(x)x
phe1 <- nlme(conc~phenoModel(Subject, time, dose, lCl, lV),
data = Phenobarb,
fixed = lCl+lV~1,
random= pdDiag(lCl+lV~1),
start = c(-5,0),
na.action = na.include,
naPattern = ~!is.na(conc))
phe.ranef <- ranef(phe1,augFrame=TRUE)
plot(phe.ranef, form=lCl~Wt+ApgarInd)
[Error in max(length(x0), length(x1), length(y0), length(y1)) :
Argument "x0" is missing, with no default]
The cause is plain to see: in plot.ranef.lme we have
staple.e...
2006 Jan 27
1
how calculation degrees freedom
...me() on the following model:
> formula(my data.gd)
dLt ~ Lt | ID
TasavB<- function(Lt, Linf, K) (K*(Linf-Lt))
my model.nlme <- nlme (dLt ~ TasavB(Lt, Linf, K),
data = my data.gd,
fixed = list(Linf ~ 1, K ~ 1),
start = list(fixed = c(70, 0.4)),
na.action= na.include, naPattern = ~!is.na(dLt))
> summary(my model.nlme)
Nonlinear mixed-effects model fit by maximum likelihood
Model: dLt ~ TasavB(Lt, Linf, K)
Data: my data.gd
AIC BIC logLik
13015.63 13051.57 -6501.814
Random effects:
Formula: list(Linf ~ 1 , K ~ 1 )
Level: ID
Structure: Ge...
2004 Sep 18
0
Pharmacokinetics using R
...ome assistance from the group. The following code
works fine in S-Plus (Population estimates and MAP estimates look reasonable
).
cs.fit<-nlme ( CONC~phenoModel(CID,TIME, DOSE, lCl, lV),
fixed = lCl+lV ~1, random = pdDiag(lCl+lV ~1),
data = cs1grp, start = c(-5, 0), na.action=na.include, naPattern = ~
!is.na(CONC)
)
But if I run the same problem in R, I get the following error: "Error in
chol((value + t(value))/2) : the leading minor of order 1 is not positive
definite"
These are simulated data with a total of 100 subjects studied at one dose
level and...
2006 Jan 26
0
degrees freedom in nlme
...) on the following model:
> formula(my data.gd)
dLt ~ Lt | ID
TasavB<- function(Lt, Linf, K) (K*(Linf-Lt))
my model.nlme <- nlme (dLt ~ TasavB(Lt, Linf, K),
data = my data.gd,
fixed = list(Linf ~ 1, K ~ 1),
start = list(fixed = c(70, 0.4)),
na.action= na.include, naPattern = ~!is.na(dLt))
> summary(my model.nlme)
Nonlinear mixed-effects model fit by maximum likelihood
Model: dLt ~ TasavB(Lt, Linf, K)
Data: my data.gd
AIC BIC logLik
13015.63 13051.57 -6501.814
Random effects:
Formula: list(Linf ~ 1 , K ~ 1 )
Level: ID
Structure: Ge...
2006 Feb 02
1
Significance of degrees of freedom in nlme
Dear Dr. Bates,
Thank you very much for your response. I had consulted
the algorithm described in Pinheiro and Bates.
However, what I don't understand (among other things)
is why my two parameters appear to be estimated at
different grouping levels (based on the DF values).
Affect this different values of DF at the estimates
parameters? The estimates fixed effects were get at
the same level of
2005 Nov 09
1
strategies to obtain convergence using nlme
Hello. I am working on an analysis involving the nonlinear mixed model
function (nlme) in R. The data consist of measures of carbon fixation
by leaves as a function of light intensity and the parametric function
(standard in this area because it has a biological interpretation) is a
non-rectangular hyperbola. I cannot get the nonlinear mixed model
(nlme) function to converge cleanly. I am