similar to: translating R code to C code

Dear Mr Peter Dalgaard and Mr Dieter Menne, I sincerely thank you for helping me out with my problem. The thing is taht I already have calculated SENS = Gg / (Gg + Bg) = 89.97% and SPEC = Bb / (Bb + Gb) = 74.38%. Now I have values of SENS and SPEC, which are absolute in nature. My question was how do I interpret these absolue values. How does these values help me to find out wheher my model is

Dear all; Does anyone know how to add grid lines to a persp plot? I've tried using lines(trans3d..) but the lines of course are superimposed into the actual 3d surface and what I need is something like the plot shown in the following link: http://thermal.gg.utah.edu/tutorials/matlab/matlab_tutorial.html I'll appreciate any ideas Thanks PM

Dear all; I have a function written in R that returns as a list of values as output that has associated some user defined attributes to it. How can hide these attributes when printing the output on screen? I'm using R-2.8.1 on WinXP....it's like hiding the attr of the output from the scale function.... Thanks in advance PM

Sorry. Let me try again then. I am trying to find "significant" predictors" from a list of about 44 independent variables. So I started with all 44 variables and ran drop1(sep22lr, test="Chisq")... and then dropped the highest p value from the run. Then I reran the drop1. Model: MIN_Mstocked ~ ORG_CODE + BECLBL08 + PEM_SScat + SOIL_MST_1 + SOIL_NUTR + cE + cN +

Dear all; This must have a rather simple answer but haven't been able to figure it out: I have a data frame with say 2 groups (group 1 & 2). I want to select from group 1 say "n" rows and calculate the mean; then select "m" rows from group 2 and calculate the mean as well. So far I've been using a for loop for doing it but when it comes to a large data set is

Hi, Correct me if I am wrong but can I translate the R code into Matlab via this package. ie I have a script in R, if I run this package on a Unix emulator can I get the R code displayed in Matlab format ( R code changed into Matlab code). If that is possible that would be great and if so how. Also, If this program cannot do this do you know one that can do this: Regards, James Flood

Here are several ways to get there, but your original loop is fine once it is corrected: > for (i in 1:2) smean[i] <- mean(toy$diam[toy$group==i][1:nsel[i]]) > smean [1] 0.271489 1.117015 Using sapply() to hide the loop: > smean <- sapply(1:2, function(x) mean((toy$diam[toy$group==x])[1:nsel[x]])) > smean [1] 0.271489 1.117015 Or use head() > smean <- sapply(1:2,

Hi Pedro, This may not be much of an improvement, but it was a challenge. selvec<-as.vector(matrix(c(nsel,unlist(by(toy$diam,toy$group,length))-nsel), ncol=2,byrow=TRUE)) TFvec<-rep(c(TRUE,FALSE),length.out=length(selvec)) toynsel<-rep(TFvec,selvec) by(toy[toynsel,]$diam,toy[toynsel,]$group,mean) Jim On 4/3/16, Pedro Mardones <mardones.p at gmail.com> wrote: > Dear all; >

Dear all; Is there any way to make this to work?: .x<-rnorm(50,10,3) .y<-.x+rnorm(50,0,1) X<-data.frame(.x,.y) colnames(X)<-c("Xvar","Yvar") Ytext<-"Yvar" lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type "Yvar" and the model should fit....

Dear R users; Is it possible to get the row and column number of a particular entry in a dist object? Let's say that I want to find the position of the value 1.1837 (the last entry on the dist object below), that is [6,3]. Can I get those values without transforming the object to a matrix?, i.e. working with the dist object only. 1 2 3 2 0.23935864

Dear all; A very basic question. I have the following data: ************************************************************************************ A <- 1/1000*c(347,328,129,122,18,57,105,188,57,257,53,108,336,163, 62,112,334,249,45,244,211,175,174,26,375,346,153,32, 89,32,358,202,123,131,88,36,30,67,96,135,219,122, 89,117,86,169,179,54,48,40,54,568,664,277,91,290,

Hi, I am trying to load into R a MATLAB format file (actually, as saved by octave). The file is about 300kB but R complains with a memory allocation error: > library(Rcompression) > library(R.matlab) Loading required package: R.oo Loading required package: R.methodsS3 R.methodsS3 v1.2.0 (2010-03-13) successfully loaded. See ?R.methodsS3 for help. R.oo v1.7.2 (2010-04-13) successfully

I'd echo a lot of what has been said about this by the folk who have been making R work so well. One of the main difficulties is that the environment of computations affects relative performance. e.g., what settings did a distro package builder choose. I note that my 3 GHz Dual Core machine running Ubuntu 8.04 gets octave 3.0.0 octave:6> tic; a = a + 1; toc Elapsed time is 0.120027

I can't get the PERL subexpression translated to R. Following, for example, B. Ripley's http://finzi.psych.upenn.edu/R/Rhelp02a/archive/58984.html I am using sub, but it looks like an ugly substitute. Assume I want to extract the first alpha part and the first numeric part, but only if they are in sequence. Do I really have to use the sub twice, first extracting the first variable, then

Hi there, I hope I can get advice regarding the calculation of leverage values or studentized residual values of a non-linear regression model. It seems like rstudent() does not work on a nls object. Many thanks in advance! Best regards, Xingli

We have extracted parameters from physiological measurements by fitting SSlogis-like curves with nlsList and nlme. We presented residuals plot in a paper, but a referee argues that these cannot be included (too technical), and r-square values should be given instead to compare the goodness of fit with those of other authors. I remember that 30 years ago in my stat 101, I learned that r-square is

Dear List, creating factors in a given non-default orders is notoriously difficult to explain in a course. Students love the ifelse construct given below most, but I remember some comment from Martin M?chler (?) that ifelse should be banned from courses. Any better idea? Not necessarily short, easy to remember is important. Dieter data = c(1,7,10,50,70) levs =

Hi. I'm embarking on my first attempt at creating my own panel function for lattice graphics, and despite all of my online research and pouring through the documentation, I cannot figure out how to solve my particular problem. Hopefully, a generous fellow R user can help. I have some data that is split into two groups: some "actual" data, and some simulated data,

I read somewhere that vector graphics such as eps or dpf are more favorable than alternatives (jpeg, bmp or png) for publication because vector graphics scale properly when enlarged. However, my problem is that the file generated from a graph of fixed size is too large (in the order of 10MB) because of many data points in multiple scatterplots. Any suggestions? Thanks, Gang [[alternative HTML

Dear R and lme4 users- I am trying to fit a mixed-effects model, with the glmer function in lme4, to right-skewed, zero-inflated, non-normal data representing understory grass and forb biomass (continuous) as a function of tree density (indicated by leaf-area). Thus, I have tried to specify a Gamma distribution with a log-link function but consistently receive an error as follows: >