Displaying 12 results from an estimated 12 matches similar to: "Nolinear mixed-effects models (nlme)"
2005 Jun 30
1
Nolinear mixed-effects models (nlme)
Hello,
I am trying to fit a nonlinear model of the form of:
A*x^b*exp(-c*x)
This represents a lactation curve. I have a bunch of cows, so I want
COW to be a random effect.
I have been trying the following code with very littel success:
> fm1 <- nlme(yield ~ A*(DIM^B)*(exp(-C*DIM)),
+ data = group,
+ fixed = A + B + C ~ 1,
+ start = c(A = 20, B =
2011 Dec 23
3
Applying a function
Hi,
I need help writing a function
I capture seal pups mutliple times during the lactation season in order to
monitor their growth rate. When I release them, the recovery (mother-pup)
time is not the same for all individuals. I want to know if individuals that
recover their mother the fastest are the ones with the highest growth rates.
So, I noted at every release if the pup
2007 Sep 04
2
multiphasic growth curve analysis
Greetings R Help Group,
How does one effect a multiphasic logistic growth model with 4 phases (e.g. Koops 1986; Weigel, Craig, Bidwell and Bates 1992; Grossman and Koops 2003) with R.
Before writing to the group, the R help archives were searched, the web was searched with Google, Venables and Ripley 2002 was consulted, Pinheiro and Bates 2000 was consulted, Bates and Watts 2007 was bought and
2007 Aug 21
2
Optimization problem
Hello Folks,
Very new to R so bear with me, running 5.2 on XP. Trying to do a zero-inflated negative binomial regression on placental scar data as dependent. Lactation, location, number of tick larvae present and mass of mouse are independents. Dataframe and attributes below:
Location Lac Scars Lar Mass Lacfac
1 Tullychurry 0 0 15 13.87 0
2 Somerset 0 0 0
2004 Aug 19
0
nlme R vs S plus
Hi all,
I'm a PhD student at sydney uni and am trying to run a non linear mixed
model program to obtain estimates of parameters describing dairy cow
lactation curves. At present, I have been able to get the data to converge
using the S plus (S plus 2000) nlme function. However, when I put the same
data into R (R 1.9.0), add in the nlme package and run the code, it does
not converge by the
2012 Sep 21
0
using neural network in R (nnet)
Hi all,
I have considered neural network to classify the health status of the cow.
I found a very neatly written R codes for classification method in
here<http://home.strw.leidenuniv.nl/~jarle/IAC/RRoutines/classification-example.R>
.
It would be very helpful if you can answer some of the questions, that I am
struggling with,
I have set of time series data from different animals, I use
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Cordial saludo adjunto la base de datos y el script:
eu60<- read.csv(file.choose(), header=T, sep=";", dec=".", row.names=1)
eu60.pca <- PCA(eu60, quali.sup=19)
eu60.data <- cbind.data.frame(eu60[,19], eu60.pca$ind$coord)
eu60.ellipse <- coord.ellipse(eu60.data, bary=TRUE)
plot.PCA(ellipse=eu60.ellipse, cex=0.8)
El 4 de diciembre de 2013 17:35, Camilo Calle
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Hola, ¿qué tal?
Tu problema es que tienes agrupaciones de países (p.e., ASIA_MERIDIOL)
con un solo respresentante. Las matrices con las que construyes las
elipses son degeneradas (más bien, no existen: sospecho que tienen que
ver con la covarianza... ¿de un único caso?).
Elimina las agrupaciones triviales.
Un saludo,
Carlos J. Gil Bellosta
http://www.datanalytics.com
El día 4 de diciembre de
2013 Dec 04
2
AYUDA CON ERROR CON LA LIBRERIA PCA
Cordial saludo, soy principiante en R y estoy haciendo un análisis
multivariado de datos, y necesito hacer las elipses de confianza donde la
variable 19 es cualitativa suplementaria y el resto son variables activas;
tengo el siguiente código:
eu60 <- read.csv(file.choose(), header=T, sep=";", dec=",", row.names=1)
### capturar datos
eu60.pca <- PCA(eu60, quali.sup=19) ##
2000 Nov 10
3
NLS
Hello,
I try to do a very simple nonlinear regression. The function is
y = (b0 + b1*x1 + b2*x2 + b3*x3) * x4^b4
I think I do everything well, but as I set the starting value of b4 to 0 (it
is the theoretically sane starting value), it converges very quickly, and to
the wrong solution. Wrong in a sense, that 1) we do not expect this and 2) we
do not get this on E-Views, Stata and SAS. I do not
2015 Jun 19
2
Sobre data.table
Mª Luz,
si el comando de Carlos te devuelve 0 es que no hay NA's.
Da igual que tus columnas sean caracteres o número.
Lo que intuyo es que tienes celdas con la frase "NA" que interpretas como NA.
Mandanos el summary de tu data.table y lo vemos...
----- Mensaje original -----
De: "MªLuz Morales" <mlzmrls en gmail.com>
Para: "Carlos J. Gil Bellosta"
2009 Dec 17
2
some help regarding combining columns from different files
Dear all,
Here is my code which am using to combine 5th column from different data
sets.
Here is the function to do my job
genesymbol.append.file <-NULL
gene.column <- NULL
readGeneSymbol <- function(files,genesymbol.column=5){
for(i in fnames){
temp <- read.table(fnames,header=T,sep="\t",stringsAsFactors=F,quote="\"")