similar to: More help need on Von Bertalanffy Growth Curves

Displaying 20 results from an estimated 100 matches similar to: "More help need on Von Bertalanffy Growth Curves"

2012 Sep 04
3
Comparing Von Bertalanffy Growth Curves
I am trying to compare Vbert growth curves from several years of fish data. I am following the code provided by: http://www.ncfaculty.net/dogle/fishR/gnrlex/VonBertalanffy/VonBertalanffy.pdf. Specifically the section on VBGM Comparisons between groups. ? This code is pretty cut and dry. I am able to run it perfectly with the "fake" data that is provided. But when I run it with my own
2018 May 16
1
Systemfit Question
I can't get my simultaneous equations to work using system fit. Please help. #Reproducible script Empdata<- read.csv("/Users/ngwinuiazenui/Documents/UPLOADemp.csv") View(Empdata) str(Empdata) Empdata$gnipc<-as.numeric(Empdata$gnipc) install.packages("systemfit") library("systemfit") pdata <- plm.data(Empdata,
2018 May 29
0
How to generate a conditional dummy in R?
Hi Faradj, What a problem! I think I have worked it out, but only because the result is the one you said you wanted. # the sample data frame is named fkdf Y2Xby3<-function(x) { nrows<-dim(x)[1] X<-rep(0,nrows) for(i in 1:(nrows-2)) { if(!is.na(x$Y[i])) { if(x$Y[i] == 1 && any(is.na(x$Y[(i+1):(i+2)]))) X[i]<-1 if(i > 1) { if(X[i-1] == 1) X[i]<-0 } }
2018 May 29
1
How to generate a conditional dummy in R?
Dear Jim, wow! It worked! Thanks a lot. I did as you suggested and it worked well with the real data. Although it gave me this error: Error in if (!is.na(x$Y[i])) { : argument is of length zero. For some reason the X1 produced less observations than it is in the data. But it's not a big deal - I identified those cases and simply deleted from the data (it was countries that only appeared
2018 May 16
0
Systemfit
Sadly you failed to set your email program to send plain text and the data is corrupted at my end. I also think you need to reduce the size of the data set... the intent here is to increase your understanding, not debug your particular analysis. I will say that I am having a very challenging time understanding what you are trying to accomplish though. What are the equations that you think need
2018 May 28
3
How to generate a conditional dummy in R?
Hi everyone, I am trying to generate a conditional dummy variable ?X" with the following rules set X=1 if Y is =1, two years prior to the NA. [0,0,NA]. For example, if the pattern for Y is 0,0,NA then the X variable is =0 for all the two years prior to the NA. If the pattern for Y is 0,1,NA or 1,0,NA then the X =1 . To be clear, if 1,1,NA then the X=1 that first specific year, it
2018 May 15
2
Systemfit
OK, Let's try this again! Here is the reproducible script; it is long because I had to copy the panel dataset here. My question is related to systemfit; I don't know how to get the result for the entire panel. #Reproducible script Empdata<- read.csv("/Users/ngwinuiazenui/Documents/UPLOADemp.csv") View(Empdata) install.packages("systemfit")
2003 Aug 26
1
Getting out of an embedded function safely - use try?
Helpers. An instrument sends me data that is mostly nonlinear. I have a group of functions to manipulate this data so that it is useful to the user. One of them involves a nls model that called to fit a line to the data and returns the fits. This works well 99 out of 100 times. Occasionally, the sensor sends some bad data to which a nls model cannot be fit. When that happens, the nls function
2006 Jul 14
3
Migration not updating fields
So I have this fairly basic migration bit of code class AddCounterCache < ActiveRecord::Migration def self.up add_column ''products'', ''backlog_items_count'', :integer, :default => 0 end def self.down remove_column ''products'', ''backlog_items_count'' end end What I want to do in that is automatically
2006 May 24
1
problem-nlme
Hi, I have great problems with my work in R. I look for to model the growth of fish. I have "Longitudinal data", a serie of repeated measures for each individual. Using the corresponding packages "nlme" in R. I treat to fit to the data different growth functions, wich were entered by me. Unfortunately for no it was arrived at the convergence, several error messages appeared. I
2006 Jan 26
0
degrees freedom in nlme
I'm having hard time understanding the computation of degrees of freedom when runing 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,
2006 Jan 27
1
how calculation degrees freedom
Hi, I' m having a hard time understanding the computation of degrees of freedom when runing 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,
2008 Feb 26
0
NLS -- multiplicative errors and group comparison
Hello, I am attempting to fit a non-linear model (Von Bertalanffy growth model) to fish length-at-age data with the purpose of determining if any of the three parameters differ between male and female fish. I believe that I can successfully accomplish this goal assuming an additive error structure (illustrated in section 1 below). My trouble begins when I attempt this analysis using a model
2012 Jan 25
1
Re: docs: Remove outdated LaTex documentation.
On Wed, 2012-01-25 at 15:55 +0000, Xen patchbot-unstable wrote: > # HG changeset patch > # User Keir Fraser <keir@xen.org> > # Date 1327506767 0 > # Node ID 4271634e4c86568b6bf2241ebf9be4a82ab430bf > # Parent a2a8089b1ffbf5757ca3191cb8f74a5f1ed7fed1 > docs: Remove outdated LaTex documentation. Nice. > @@ -82,7 +70,7 @@ > $(MAKE) -C xen-api clean >
2011 Oct 08
1
Delete files with system command on Windows 7
Under MacOS I use the following script to process my latex documents: pdflatex -halt-on-error document.tex bibtex document.aux pdflatex -halt-on-error document.tex pdflatex -halt-on-error document.tex rm *.aux *.bbl *.blg *.log *.nlo *.thm How can I realise this under Windows 7? -- View this message in context:
2001 Sep 07
3
fitting models with gnls
Dear R-list members, Some months ago I wrote a message on the usage of gnls (nlme library) and here I come again. Let me give an example: I have a 10 year length-at-age data set of 10 fishes (see growth.dat at the end of this message) and I want to fit a von Bertalanffy growth model, Li= Linf*(1-exp(-k*(ti-t0))) where Li = length at age i, Linf= asymptotic length, k= curvature parameter, ti=
2007 Jun 14
1
R programming question
Dear All., I've created R-code for which a user will be asked to choose between 2 analyses. I've written one function for each type of analysis. Within each function, the users is prompted to enter information. An example is: cat("Enter value for lower Linf :\n") L1<-scan(n=1) cat("Enter value for upper Linf :\n") L2<-scan(n=1)
2012 Jan 17
2
How to loop on file names
Dear all, I need to do the same procedure on several files. But I don't know how to refer to the file name. Here is an example of what I am trying to do. List of files: file1(A,B,C, D1...Dn), file2(A,B,C,E1,...,En), file3(A,B,C,F1,...,Fn) Procedure I want to apply on each file: dft <- melt(df,id=c('A','B','C')) dft$X <- substr(dft$variable,1,3) dft$Y <-
2006 Feb 22
0
Re: [PATCH] Fix IPSec for Xen checksum offload packets (Jon Mason)
Hello Xen folks, I have independently verified that this patch indeed fixes the issue (I posted a message about the issue over the summer: http://lists.xensource.com/archives/html/xen-devel/2005-08/msg00114.html). I used changeset 8911 of xen-unstable.hg. The patch as written expects kernel linux-2.6.16-rc2, but changeset 8911 uses kernel 2.6.16-rc4. I verified that the patch works with
2009 Dec 17
2
Sweave Makefile issue
Dear R-specialists, I am trying to create a Makefile that will first convert all my .Rnw files into .tex files and then, that will run the LaTeX compiler to produce a pdf document. This issue has been discussed before. Hence, I've basically adapted a Makefile I found at http://n4.nabble.com/R-Sweave-R-and-complex-latex-projects-td810020.html#a810023 to make it compatible with a Windows