similar to: nonlinear curve fit of an implicit function

Hi- I'm a biologist trying to figure out the growth rate of salamanders in different ponds. I collected individuals from various populations at different dates, and using the size and date collected, I want to figure out the growth curve of each population. My question is: How do I fit my data to a Gompertz function in R? Thank you so much! Sarah -- View this message in context:

Dear R- Community, to learn i reanalysed some data provided and analysed by Zuur et. al. in their book "Mixed effect models and Extensions in Ecology with R". When i run the last command i get a warning message i dont understand. Loyn<- read.table(file = "loyn.txt",header = TRUE) Loyn$L.AREA<- log10(Loyn$AREA) fGRAZE <-factor(Loyn$GRAZE) M0<- lm(ABUND~ L.AREA

Hello, This is my first post to the help request list, so I'm going to err on the side of giving too much information. I'm working on writing a simulation in which agents will make repeated production and exchange decisions with randomly chosen partners. The idea is, all agents can produce two goods which they want to consume, they choose a value t in [0,10] which sets their production

Hi, I followed the installation instruction step by step with the wine 1.3.13 package. I stick at point 3.1 user guide: using winecfg. If I input /usr/local/bin/winecfg or only winecfg in the wine-1.3.13 directory, the error message -bash: winecfg: command not found appears. There is a directory winecfg under wine-1.3.13/programs/ but no executable files. The wine package is installed under

Dear R Helper Community! Thank you for all your help and suggestions. For your reference and any future person searching the archives, here is the solution that did what I wanted it to do. As background, my goal was to find the coefficients for the following equation form: y ~ c1 * x1 * x2 ^ -c2 *x3 ^ c3 where y, x1, x2, and x3 are observed data, and c1, c2 and c3 are regression

Hello, I have a problem concerning logistic regressions. When I add a quadratic term to my linear model, I cannot draw the line through my scatterplot anymore, which is no problem without the quadratic term. In this example my binary response variable is "incidence", the explanatory variable is "sun": > model0<-glm(incidence~1,binomial) >

Hello, I am trying to load the package SparseM. It seems that I have successfully installed SparseM (version 0.78), but I did not succeed in loading the SparseM package into R 2.7. Does anybody know a trick for loading SparseM? Thanks in advance, Heike > library(SparseM,lib.loc=my.lib.loc) Error in packageDescription(pkg)$Version : $ operator is invalid for atomic vectors In addition:

Dear moderators, when I installed the latest version of R (R2.10.1) under Microsoft Vista (service pack 2), I ran into problems associating Rgui.exe with .RData files. On doubleckicking such files in explorer, they open in a Rterm window. Trying to associate Rgui.exe with the Rdata files via control panel / default programs does not work - Rgui is not added to the list of recommended programs. I

Hello all, I'm jumping into this mailing list because my question still unsolved after Googling the web. Do you know any performance of sizing recommendations about Samba 4.7.1 ? For few informations : 2vCPUs / 1 Core 8Go of RAM 140 simultaneous Windows users / 250 at most 20 NFS shares mounted via fstab This question because my RAM is all eated up in the buffer/cache (normal according

Hello list. I have a perfectly working PV host, with this configuration: kernel = "/boot/vmlinuz-2.6.18.8-xen-3.3.0-7mdv" ramdisk = "/boot/initrd-2.6.18.8-xen-3.3.0-7mdv.img" root = "/dev/sda1 ro" extra = "(hd0)/boot/grub/menu.lst" memory = 256 maxmem = 512 name = "sexonthebeach" uuid = "f36962f5-0dec-4708-84a0-f5b4dea48d34" disk = [

Hi I am struggling to fit a non-linear trend using the likfit function in geoR. Specifically I want a sigmoidal function, something like SSfpl in the nls package to fit the trend. But it seems trend.spatial in geoR only works with lm or glm type models. Any ideas how I can specify the model to calculate the kriging parameters using REML, including the parameters of a sigmoidal trend function

Hello, I am attempting to utilize the 'alabama' package to solve a constrained nonlinear optimization problem. The problem has both equality and inequality constraints (heq and hin functions are used). All constraints are smooth, i.e. I can differentiate easily to produce heq.jac and hin.jac functions. My initial solution is feasible; I am attempting to maximize a function, phi. As

Dear R-helpers, I tried to create a 3D surface showing the interaction between two continuous explanatory variables; the response variable is binary (0/1). The model is: model<-glm(incidence~sun*trees,binomial) then I used "wireframe" to create a 3D plot: xyz<-expand.grid(sun=seq(30,180,1),trees=seq(0,4000,10)) xyz$incidence<-as.vector(predict(model,xyz))

Dear list-members, I am trying to use R to conduct a meta-analysis, i.e. I'd like to use a multi-level model to integrate the findings of a number of primary research studies. I set up a simple two level-model (only summary statistics are provided by each study) as follows: sapp.lme <- lme(D ~ 1, data = sapp.frame, random = ~ 1 | STUDYNR, weights=varFixed(~-1+STDERR_D),na.action =

Hello everyone, I am looking into time series data compression at the moment. The idea is to fit a curve on a time series of n points so that the maximum deviation on any of the points is not greater than a given threshold. In other words, none of the values that the curve takes at the points where the time series is defined, should be "further away" than a certain threshold from the

Hello useRs, I'm using the command "solnp" in package "Rsolnp" to solve a general nonlinear programming problem. But I got an error that " the leading minor of order 15 is not positive definite ". Can anybody tell what may cause this error? Does it have something to do with the starting values? Thanks a lot!!! Xiaoxi [[alternative HTML version

I am using R on a Windows XP professional platform. The following code is part of a bigger one CODE press=function(y,x){ library(qpcR) models.press=numeric(0) cat("\n") dep=y print(dep) indep=log(x) print(indep) yfit=dep-PRESS(lm(dep~indep))[[2]] cat("\n yfit\n") print(yfit) yfit.orig=yfit presid=y-yfit.orig press=sum(presid^2)

Dear R users. I have data observed on the surface of a torus, and am trying to fit the nonlinear regression using the geodesic equation on a torus. Could anyone give me a helpful advise on this problem? I would definitely appreicate your reply. Sincerely, SUNGSU KIM [[alternative HTML version deleted]]

Hi, I want to include a vector representing the sites - environmental data correlation in a PCA. I currently use prcomp (no scaling) to perform the PCA, and envfit to retrieve the coordinates of the environmental data vector. However, the vector length is different from the one obtained in CAnoco when performing a species - environmental biplot (scaling -2). How can I scale the vector in order to

Basically all platforms have a proper "mkdir -p". Autoconf has install-sh as fallback when using AC_PROG_MKDIR_P, which is also hardened against races if it is recent enough. Update that script and use MKDIR_P whereever possible. Installs fine in my tests and avoids the "mkdir: cannot create directory '?': File exists" messages along the way. Greetings, Eike --