similar to: setting new working directories

Hello. Please excuse this off-topic request, but I know that the question has been debated in summary form on this list a number of times. I would find a paper that lays out the advantages and disadvantages of using different types of SS in the context of unbalanced data in ANOVA, regression and ANCOVA, especially including the use of different types of contrasts and the meaning of the

Hi I run R in Windows. Is there a simple way of changing the prompt symbol ">" to, say, "R>" ? (Not just for a temporary session, but every time R command window is opened.) The documentation of doing this is rather "sparse". Much appreciated for your assistance. Jacob Jacob L van Wyk Department of Statistics University of Johannesburg, APK P O Box 524

Hello. I am trying to fit a non-rectangular hyperbola function to data of photosynthetic rate vs. light intensity. There are 4 parameters that have to be estimated. I find the nls function very difficult to use because it often fails to converge and then gives out cryptic error messages. I have tried playing with the control parameters but this does not always help. Is there another

Hi, I am a newbie to R, just trying to switch from Splus. I am wondering to know if there is any such command in R as "attach" in Splus which can be used to attach the full directory. Also, any idea/referrence about, how to load c functions in R would be highly appreciated. Thanks, Utsav

Hello. I have a script in which I repeatedly fit a nonlinear regression to a series of data sets using nls and the port algorithm from within a loop. The general structure of the loop is: for(i in 1:n){ … extract relevant vectors of dependent and independent variables … … estimate starting values for Amax and Q.LCP…

Dear friends - windows R 3.3.3 - sorry to ask a simple question - but I cannot make setwd work properly in scripts In the example below I have made a directory in C (firstdir) and a directory in that (secdir) and the intention is to change directory to the second from the first - it works when I put the entire path but not the tilde - what am I missing? I was around rwf 2.14 as per the help

Hello. I am trying to determine whether I should be using ML or REML methods to estimate a linear mixed model. In the book by Pinheiro & Bates (Mixed-effects models in S and S-PLUS, page 76) they state that one difference between REML and ML is that « LME models with different fixed-effects structures fit using REML cannot be compared on the basis of their restricted likelihoods. In

[Env: Win XP, R 2.14.2, R 2.15.0] I have a replacement function for setwd() in my .Rprofile which displays the current R path in the R window title. It no longer works in R 2.15.x, giving the error below. Worse, the error prevents the rest of my .Rprofile script from completing. Is there some way to rescue this, i.e., preserve this behavior in R 2.15? If not, how can I modify my script so it

In my .Rprofile for Windows, I had the following functions defined to mirror a few features I miss from linux: (a) replace setwd() with a version that stashes the current directory so it can be easily restored (b) writes a short version of the current R directory to the Windows title bar: I can always see where I am, with multiple Rgui windows. (c) creates a cd() shorthand for setwd(), but

Hello, and please excuse this off-topic question, but I have not been able to find an answer elsewhere. Consider a value Z that is calculated using the product (or ratio) of two means X_mean and Y_mean: Z=X_mean*Y_mean. More generally, Z=f(X_mean, Y_mean). The standard error of Z will be a function of the standard errors of the means of X and Y. I want to calculate this se of Z. Can someone

Hello. Following pages 342-347 of Pinheiro & Bates, I am trying to write a self-starting nonlinear function (a non-rectagular hyperbola) to be used in nonlinear least squares regression (and eventually for a mixed model). When I use the getInitial function for my self-starting function I get the following error message: > getInitial(photo~NRhyperbola(Irr,theta,Am,alpha,Rd),dat) Error

Hello. Slope estimates in lme are shrinkage estimates which pull the OLS slope estimates towards the population estimates, the degree of which depends on the group sample size and the distance between the group-based estimate and the overall population estimate. Although these shrinkage estimates as said to be more precise with respect to the true values, they are also biased. So there is a

Earlier, I posted the following question: I want to superimpose histograms from three populations onto the same graph, changing the shading of the bars for each population. After consulting the help files and the archives I cannot find out how to do this (seemly) simple graph. To be clear, I want - a single x axis (from -3 to 18) - three groups of bars forming the histograms of each population

Hello. I have data (plant weights over time) that are non-linear and in which the variance increases over time. I have to estimate the first derivatives of plant weight given time (i.e. growth rate) and their se, using a regression smoother, and I have been considering cubic spline smoothers. However, I do not know if this can be done given that the error variance would increase over time.

I believe file.choose() remembers the last choice, and repeats that location the next time you call it. This is true when it is called at top level or from within a function. The first time you call it in a session, it will default to the current working directory, but not after that. Front ends are allowed to replace the underlying function, so that may depend on which front end you are

I've found the following strange behaviour R (RStudio) which has been confirmed by another user in RGui. Inside a script I want to set two variables: default.wd = getwd() tmp.wd = setwd(choose.dir()) After choosing tmp.wd the value of default.wd is shown in Workspace, but getwd() is giving back the correct string of tmp.wd. Is there a workaround for the problem? I'm working on

Dear helpers, I've looked in the help files (maybe not very thoroughly but I looked) and I couldn't find a straightforward way to permanently set the working directory (where I save and read files). Each time I startup R the working dir is automatically "C:/R/bin" [using:getwd()], and I know I can change it using setwd [for example setwd("C:/R/DATA"), but it's only

I've been working on a small personal project that needs to select files for manipulation from various directories and move them around in planned ways. file.choose() is a nice way to select files. However, I've noticed that if file.choose() is called within a function, it is the directory from which that calling function has been invoked that is displayed by file.choose(). This is not

Hello. I am sorry for posting a (seemingly) simple question, but I have just spent 2 hours trying to find the answer, without success. I want to make a histogram with conditioning on a factor, using Trellis graphics. However, I do not want any colours (only black and white) either in the histograms or in the strip. There must be some simple argument but I can’t find it. Here is my code so

To avoid angry replies, let me first say that I know that the use of Type III sums of squares is controversial, and that some statisticians recommend instead that significance be judged using the non-marginal terms in the ANOVA. However, given that type III SS is also demanded by some… is there a function (equivalent to drop1 for lm) to obtain type III sums of squares for mixed models using the