Re: [R] Can anybody help me understand AIC and BIC and devise a new metric?

Hi, one comment: Claeskens and Hjort define AIC as 2*log L - 2*p for a model with likelihood L and p parameters; consequently, they look for models with *maximum* AIC in model selection and averaging. This differs from the vast majority of authors (and R), who define AIC as -2*log L + 2*p and

Re: [R] Help with a problem

Mike, I am slightly unclear on what you want to do. Do you want to check rows 1 and 7 or 1 *to* 7? Should c1 be at least 100 for *any one* or *all* rows you are looking at, and same for c2? You can sort your data like this: data - data[order(data$ds),] Type ?order for help. But also do this

Re: [R] Help with a problem

for the help! Michael Stephan Kolassa 07/17/10 4:50 PM Mike, I am slightly unclear on what you want to do. Do you want to check rows 1 and 7 or 1 *to* 7? Should c1 be at least 100 for *any one* or *all* rows you are looking at, and same for c2? You can sort your data like this: data - data

Re: [R] Problems with normality req. for ANOVA

Hi, simulating would still require you to operationalize the lack of normality. Are the tails too heavy? Is the distribution skewed? Does it have multiple peaks? I suspect that the specific choices you would make here would *strongly* influence the result. My condolences on the client you

[R] predict.lm, matrix in formula and newdata

Dear all, I am stumped at what should be a painfully easy task: predicting from an lm object. A toy example would be this: XX - matrix(runif(8),ncol=2) yy - runif(4) model - lm(yy~XX) XX.pred - data.frame(matrix(runif(6),ncol=2)) colnames(XX.pred) - c(XX1,XX2) predict(model,newdata=XX.pred) I

Re: [R] R time series analysis

Hi, basically, you know 5 periods later. If you use a good error measure, that is. I am a big believer in AIC for model selection. I believe that arima() also gives you the AIC of a fitted model, or try AIC(arima1). Other ideas include keeping a holdout sample or some such. I'd recommend

Re: [R] repeated measurements ANOVA

Hi Alex, I'm slightly unclear as to why you would want to restructure your nice six-column data.frame (why six? One column for the data and four for the factors should make five, shouldn't it? I guess you have a subject ID in one column?) into some monstrosity which I assume you would fill

Re: [R] Uniform Distribution

Hi Alex, help.search(uniform) HTH, Stephan Am 08.09.2010 15:36, schrieb Alaios: Hello, I would like to uniformly distribute values from 0 to 200. Can someone help me find the appropriate uniform distribution generator? I would like to thank you in advance for your help. Best Regards Alex

Re: [R] exclude data for boxplot stats using mathematical operator

Try this: boxplot.stats(x[x[,2]0,2],do.conf=FALSE) HTH, Stephan e-letter schrieb: Readers, I have a data set as follows: 1,1 2,2 3,3 4,4 5,3 6,2 7,-10 8,-9 9,-3 10,2 11,3 12,4 13,5 14,4 15,3 16,2 17,1 I entered this data set using the command 'read.csv'. I want to exclude values fewer than

Re: [R] modeling and forecasting commodity time series?

Hi Luna, you may want to look at the IIF website, http://www.forecasters.org They have a mailing list for forecasters - you may get more of a response there than on a dedicated R list. HTH, Stephan Luna Moon schrieb: Hi all, Could anybody please shed some lights on me about good

Re: [R] From date to week day

Or: weekdays(as.Date(2010-05-24)) HTH, Stephan Wu Gong schrieb: ?strptime will helps. d - as.Date(01/05/2007,%m/%d/%Y) format(d, %A, %b %d, %Y) [1] Friday, Jan 05, 2007 - A R learner. __ R-help@r-project.org mailing list

Re: [R] R Packages Crack the 3,000 Mark!

Hi Bob, Muenchen, Robert A (Bob) wrote: Does anyone have a program that graphs the growth of R packages? I don't know if that historical data is around. John Fox had a slide on this in his useR 2008 talk The Social Organization of the R Project (page 7), with package counts up to March

Re: [R] Literature analysis

Hi, from what I understand, you may be interested in text mining, so perhaps you want to look at the tm package. Then again, depending on what you are really trying to do, you may be better served with perl, awk and similar tools than with R... HTH, Stephan Schwan schrieb: Dear all, i

Re: [R] forecasting

?predict HTH Stephan DispersionMap schrieb: I have some data that i ran a regression on and got the usual r output, with the a intercept and b coefficient for my independent variable. i want to forecast the number of future events using these parameters. What function / packages in R would

Re: [R] Generating permutations that always include one specific element

Hi Ray, First possibility: just select those combinations that contain AL: combos.with.AL - possible.combos[rowSums(possible.combos==AL)0,] Second possibility: create all 3-combos *without* AL: bands.without.AL - c(B, DB, DG, G, K, LB, LG, MG, O, P, PI, PK, PU, R, V, W, Y)

Re: [R] integer(0) and NA do not equal FALSE

Hi Jonathan, grep() returns a vector giving either the indices of the elements of 'x' that yielded a match or, if 'value' is 'TRUE', the matched elements of 'x' (quoting from the help page, see ?grep). So you probably want to test whether this vector is empty or not - in other words,

Re: [R] plotting

Hi teo, try lines() instead of points(). HTH Stephan teo schrieb: Hi: Could you please guide me how to plot weekly.t2. Below are my values and I am only able to plot weekly t1 but failing to add a second line representng weekly t2. Thanks. weekly.t1 [1] 228.5204 326.1224 387.2449 415.4082

[R] boot() with an array-valued statistic?

Dear guRus, is there a version of boot() that deals with array data and array-valued statistics? For example: foo - array(rnorm(120),dim=c(3,5,8)) means - apply(foo, MARGIN=c(2,3), FUN=mean) means contains the means over the first dimension of foo: a 5x8 array. Now I would like to bootstrap

Re: [R] Question regarding if statement in while loop

Hi Stephanie, it sounds like R's exception handling may help, something like this: foo - try(eblest(i, dir5, sterr5, weight5, aux5)) if ( class(foo) == try-error ) next Take a look at ?try. HTH, Stephan Stephanie Coffey schrieb: Hi all, I'm running R version 2.9.2 on a PC. I'm having a

[R] Reading a file with mixed cyrillic/latin characters

Dear useRs, I am trying to read a tab-delimited Unicode text file containing both latin and cyrillic characters and failing miserably. The file looks like this (I hope it comes across right): A B C 3 foo ФОО 5 bar БАР read.table(foo.txt,sep=\t,header=TRUE) I

Re: [R] Beginer data.frame

Hi Jean-Baptiste, two points: 1) Your variable df is a *local* variable which you define in your function myfunc(), so it is not known outside myfunc(). When you ask is.data.frame(df), R looks at the global definition of df - which is the density function of the F distribution. To make your

Re: [R] coerce vector into array - change filling sequence

Hi, you can permute array dimensions using aperm(): x - 1 : 24 z - array(x, dim=c(6,2,2)) y - aperm(z,perm=c(3,2,1)) y[1,1,] HTH, Stephan Kohleth Chia schrieb: Dear all, When I coerce a vector into a multi dimensional array, I would like R to start filling the array along the last

Re: [R] shapiro.test

Hi, David Winsemius schrieb: snip This would imply that ozon is a list or dataframe. snip And you tried to give the whole list to a function that only wants a vector. And whenever you suspect that your data types clash, try str() to find out just what kind of thing your data is. Here:

Re: [R] adding column to data frame conditionally

Hi Kristina, Thierry's solution is certainly the correct one in terms of keeping within R's philosophy... but I personally find a series of conditional assignments easier to understand - see below for an example. HTH, Stephan # # Example

Re: [R] glm.diag

Hi Helga, did you load the boot library, which contains glm.diag(), by calling library(boot)? HTH Stephan Helga margrete holmestad schrieb: I have made a poisson regression by using glm. Then I want to check if I have over-dispersion in my model. I tried to use glm.diag(fit.1), but then R

Re: [R] create new variable: percentile value of variable in data frame

Hi Jon, does the empirical cumulative distribution function do what you want? dat$q.score - ecdf(dat$score)(dat$score) ?ecdf HTH Stephan Jonathan Beard schrieb: Hello all, Thanks in advance for you attention. I would like to generate a third value that represents the quantile value of a

Re: [R] Reading file

Have you set the correct working directory? ?setwd ?getwd HTH Stephan Robert Tsutakawa schrieb: I am trying to read a source program into a mac pro laptop, which uses Snow Leopard. R is unable to find the file containing my source program. I'm using the function source( file name). I

Re: [R] Exponential Smoothing: Forecast package

Hi Phani, to get the best Holt's model, I would simply wrap a suitable function calling ets() within optim() and optimize for alpha and beta - the values given by ets() without constraints would probably be good starting values, but you had better start the optimization with a variety of

Re: [R] Exponential Smoothing: Forecast package

this. And I did find a way around could this allow me to set MAPE as a criteria? Phani On Tue, Jun 29, 2010 at 12:47 AM, Stephan Kolassa stephan.kola...@gmx.dewrote: Hi Phani, to get the best Holt's model, I would simply wrap a suitable function calling ets() within optim() and optimize for alpha

Re: [R] process of stepwise selection

Hi Elaine, in general, stepwise selection is a very bad idea: Whittingham, M. J.; Stephens, P. A.; Bradbury, R. B. Freckleton, R. P. Why do we still use stepwise modelling in ecology and behaviour? Journal of Animal Ecology, 2006, 75, 1182-1189 HTH Stephan elaine kuo schrieb: Dear list,

Re: [R] Finding Lower Envelope of Points on a Plot?

Hi, one possibility would be to calculate the convex hull using chull(). I believe that the hull points are returned by chull() in a clockwise order (?), so the points between the rightmost and the leftmost point in the chull() result are the lower half of the convex hull. Remove these

Re: [R] Finding Lower Envelope of Points on a Plot?

the percentage of points outside it? Thanks! Asha Stephan Kolassa wrote: Hi, one possibility would be to calculate the convex hull using chull(). I believe that the hull points are returned by chull() in a clockwise order (?), so the points between the rightmost and the leftmost point

Re: [R] What is wrong with this code?

Hi, your problem is called string matching. Search for that term on rseek.org, there are a couple of functions and packages. And Wikipedia can tell you everything you ever wanted to know about string matching (and more). HTH, Stephan Cable, Samuel B Civ USAF AFMC AFRL/RVBXI schrieb:

Re: [R] how to define a function in R

Hi, I recommend that you look at the following help pages and experiment a little (maybe create a toy directory with only three or four files with a few lines each): ?files ?dir ?grep ?strsplit Good luck! Stephan jd6688 schrieb: Here are what i am going to accomplish: I have 400 files

Re: [R] = returns wrong result? Why

Hi Trafim, take a look at FAQ 7.31. HTH Stephan Trafim Vanishek schrieb: Dear all, Does anybody know the probable reason why = gives false when it should give true? These two variables are of the same type, and everything works in the cycle but then it stops when they are equal. this is

Re: [R] Operating on each row of data frame

Hi, does this do what you want? d - cbind(d,apply(d[,c(2,3,4)],1,mean),apply(d[,c(2,3,4)],1,sd)) HTH, Stephan Abhishek Pratap schrieb: Hi All I have a data frame in which there are 4 columns . Column 1 : name Column 2-4 : values I would like to calculate mean/Standard error of values

Re: [R] bootstrapping

Hi Aaron, try the argument statistic=mean. Then boot() will give you the mean turn angle in your actual data (which appears to be 6 degrees, judging from what you write), as well as the means of the bootstrapped data. Then you can get (nonparametric) bootstrap CIs by

Re: [R] Comparing dates in dataframes

Hi, it looks like when you read in your data.frames, you didn't tell R to expect dates, so it treats the Date columns as factors. Judicious use of something along these lines before doing your comparisons may help: arr$Date - as.Date(as.character(arr$Date),format=something) Then again, it

Re: [R] GARCH AIC

Hi David, str(g) gives you a ton of output, and the @fit slot has a $ics component, part of which has the promising name of AIC... (g...@fit)$ics[1] HTH, Stephan David Rubins schrieb: Hi, Is there anyway to extract the AIC and BIC from the summary statistics in fGarch package? g -

Re: [R] Exporting Graphs

Hi Karthik, I think you will need to do something like jpeg(histograms.jpg) hist(rnorm(100)) dev.off() HTH Stephan Karthik schrieb: Hello Tal, This is the code. hist(rnorm(100)) jpeg(histogram.jpeg) --- Even when I decrease the quality, I

Re: [R] Collinearity in Linear Multiple Regression

Hi Alex, I personally have had more success with the (more complicated) collinearity diagnostics proposed by Belsley, Kuh Welsch in their book Regression Diagnostics than with Variance Inflation Factors. See also: Belsley, D. A. A Guide to using the collinearity diagnostics. Computational

Re: [R] Collinearity in Linear Multiple Regression

Hi Tim, Variance proportions (and condition indices) are exactly the tools described in Belsley, Kuh Welsch, Regression Diagnostics - see my previous post. Good to see I'm not the only one to use them! BKW also describe in detail how to calculate all this using SVD, so you don't need to use

Re: [R] RPro

Hi, I like RSeek: http://www.rseek.org/ And of course searching the R-help list archives, e.g., via http://www.nabble.com/R-f13819.html Good hunting! Stephan Carl Witthoft schrieb: One thing I'll say: it's going to be much easier to Google for references to Rstat than to R . I've been

[R] Sweave: looping over mixed R/LaTeX code

Dear guRus, I would like to loop over a medium amount of Sweave code, including both R and LaTeX chunks. Is there any way to do so? As an illustration, can I create a .tex file like this using a loop within a .Rnw file, where the 1,2,3 comes from some iteration variable in R?

Re: [R] Recoding a variable

internet.use[internet.use==Never | internet.use==Don't know] - 0 internet.use[internet.use!=0] - 1 HTH, Stephan Spencer schrieb: Hi All, I'm relatively new to R. I have a variable, internet use, which ranges from Almost everyday, Several times a week, Several times a month, Seldom, Never,

[R] Backslash in sub pattern?

Dear guRus, I am trying to replace ~ by $\sim$ for TeX. However, I can't get the backslash to work. I would like to turn DV~IV into DV$\sim$IV. sub(~,$\sim$,DV~IV) = DV$sim$IV sub(~,$\\sim$,DV~IV) = DV$sim$IV sub(~,$\\\sim$,DV~IV) = DV$sim$IV sub(~,$sim$,DV~IV) = DV$\\sim$IV Alternatives

Re: [R] Sweave, backslash in sub pattern? was: Backslash in sub pattern?

[EMAIL PROTECTED] On Mon, 14 Jul 2008, Stephan Kolassa wrote: Dear guRus, I am trying to replace ~ by $\sim$ for TeX. However, I can't get the backslash to work. I would like to turn DV~IV into DV$\sim$IV. sub(~,$\sim$,DV~IV) = DV$sim$IV sub(~,$\\sim$,DV~IV) = DV$sim$IV sub(~,$\\\sim

Re: [R] Iterations

Kevin, By default, many functions only *return* a result, they don't explicitly *print* it. There is no difference in interactive mode, but there is in batch mode (e.g., in loops). Use print() or cat() for explicit printing to console. for(i in 1:100) { cat(i,\n) } HTH, Stephan

Re: [R] Display variables when running a script

?print ?cat HTH Stephan [EMAIL PROTECTED] schrieb: Hi, I know this must be a stupid question, and sorry in advance for being such a noob. But, is there way to get R to display only certain variables when running a script. I know if you want to see the value of a variable when using the

Re: [R] Newbie question: How to use tapply() on several vectors simultaneously

Hi Bertolt, by(test,INDICES=test$groupID,FUN=mean) And today's a holiday in Switzerland, so stop working already ;-) HTH Stephan Bertolt Meyer schrieb: Dear R users, I have a newbie-question that I couldn't resolve after reading through several pieces of documentation and searching the

Re: [R] Questions related to plotting boxplots of time series data

Hi Thomas, I have looked through several R books and searched the web to find answers to my questions with no results. I have an ensemble of time series data (what are essentially Monte Carlo simulations) which I would like to summarize as a time series of boxplots, by date/time at 6-hr

Re: [R] improvement of Ancova analysis

Hi Tobias, If you want to do inferential statistics with groups differing systematically on the covariate, you will need to be extra careful in your interpretation. See, e.g., Miller, G. A. Chapman, J. P. Misunderstanding Analysis of Covariance, Journal of Abnormal Psychology, 2001, 110,

Re: [R] Random number generation

Dennis, I assume that there is a set.seed() somewhere in your script, possibly in something you source()d (hopefully not in anything library()d). Have you tried successively removing/commenting parts of the script before the sample() command until the problem goes away? That way you should

Re: [R] Permutations

Hi Elke, the matrix you are trying to create has 5^21 = 476837158203125 rows and 21 columns. I'm afraid Thierry's proposal with n=21 will not fit into memory. And the file you are writing is 5^21*5*8 bytes big, about 80108643 GB. Perhaps you want to think a little more about what you are

Re: [R] Plotting a cubic line from a multiple regression

Hi Ashish, I am rather more concerned about whether what you outlined is legitimate (your question 1 below). If you are looking at children, higher AGE will be associated with higher TIV, so both variables would essentially measure the same thing (see Miller Chapman, Misunderstanding

Re: [R] quadratic programming

Hi, The CRAN Task View on Optimization may help: http://stat.ethz.ch/CRAN/web/views/Optimization.html HTH, Stephan barbara.r...@uniroma1.it schrieb: Devo risolvere un problema di minimo vincolato con vincoli di uguaglianza e un altro con vincoli di uguaglianza e disuguaglianza. Cosa posso

Re: [R] ApEn (Approximate Entropy), Total Corr, Information Interaction

Hi Vishal, re 1]: Ben Bolker very kindly shared an R reimplementation of Kaplan's Matlab code a little while ago: http://www.nabble.com/Approximate-Entropy--to21144062.html#a21149402 Best wishes Stephan Vishal Belsare schrieb: Is there any existing implementation in R/S of : 1] Pincus

Re: [R] add variable in for loop

Hi Paul, you do *not* want to do this, it takes too long and may lead to rounding errors. Vectorize everything, e.g., use sum(meanrotation). And look into ?apply, and google for the R Inferno. And no, there is no +=... Good luck! Stephan pgseye schrieb: Hi, I'm learning to write some

Re: [R] text matching and substitution

Hi Simeon, ?gsub HTH, Stephan simeon duckworth schrieb: I am trying to simplify a text variable by matching and replacing it with a string in another vector so for example in colours - paste(letters,colours(),stuff,LETTERS) find and replace with (red,blue,green,gray,yellow,other) -

Re: [R] text matching and substitution

) } On Sat, Mar 28, 2009 at 9:45 AM, Stephan Kolassa stephan.kola...@gmx.dewrote: Hi Simeon, ?gsub HTH, Stephan simeon duckworth schrieb: I am trying to simplify a text variable by matching and replacing it with a string in another vector so for example in colours - paste(letters,colours

Re: [R] text matching and substitution

red xx xxx xx xx xxx xxx xx blue xx xx xx xx x x xx xx xx xx red red xx xx xx xx xx xx xx xx xx xx xx xx x x x x which i'd like to replace with red blue red other other thanks On Sat, Mar 28, 2009 at 2:38 PM, Stephan Kolassa stephan.kola...@gmx.dewrote: Hi Simeon, I'm

Re: [R] How to generate natural cubic spline in R?

Hi, if you are looking for *natural* cubic splines (linear beyond the outer knots), you could use rcs() in Frank Harrell's Design package. HTH, Stephan David Winsemius schrieb: If one enters: ??spline ... You get quite a few matches. The one in the stats functions that probably answers

Re: [R] Does R support double-exponential smoothing?

Hi, ets() in Hyndman's forecast package allows you to specify which one of the many smoothing variants (additive/multiplicative season, damped trend, additive/multiplicative errors) you want. HTH, Stephan minben schrieb: I want to use double-exponential smoothing to forecast time series

Re: [R] model selection using ANOVA

Hi Alina, your approach sounds problematic - you can always get a smaller RSS if you add terms to your model, so your approach will always go for larger models, and you will end up overfitting. Consider information criteria, e.g., AIC or BIC, which penalize larger models. References for AIC

Re: [R] How to generate natural cubic spline in R?

Hi David, David Winsemius schrieb: The splinefun documentation indicates that natural is one of the types of cubic spline options available. That sounds good, didn't know that... rcs() has the advantage of coming with a book (Harrell's Regression Modeling Strategies). Does rcs actually do

Re: [R] Time series forecasting

Hi Perry, my impression after a very cursory glance: this looks like noise. Perhaps you should think a little more about your series - what kind of seasonality there could be (is this weekly data? or monthly?), whether the peaks and troughs could be due to some kind of external driver,

Re: [R] Citing R

citation() HTH, Stephan Tom Backer Johnsen schrieb: What is the correct citation to R in BibTeX format? I have looked in the R pages but so far without any luck. Tom __ R-help@r-project.org mailing list

Re: [R] bug when subtracting decimals?

Hi, Gavin Simpson wrote: I bemoan the apparent inability of those asking such questions to use the resources provided to solve these problems for themselves... Looking at all the people who quite obviously do NOT read the posting guide and provide commented, minimal, self-contained,

Re: [R] Deleting rows or cols that do not meet cut off

f[rowSums(f=1)0,colSums(f=1)0] Judging from your result, you want less than or equal to 1. HTH, Stephan Crosby, Jacy R schrieb: How can I delete both rows and columns that do not meet a particular cut off value. Example: d - rbind(c(0,1,6,4), + c(2,5, 7,5), + c(3,

Re: [R] Deleting rows or cols that do not meet cut off

Hi Wacek, Wacek Kusnierczyk schrieb: ... or gain a bit on performance by doing the threshold comparison on the whole matrix just once at once: dd = d = 1 d[apply(d, 1, any), apply(d, 2, any)] d[apply(dd, 1, any), apply(dd, 2, any)] Or not? Cheers, Stephan

Re: [R] Variable shortlisting for the logistic regression

Hi Marko, this may be helpful: http://www.ingentaconnect.com/content/bpl/rssb/2008/0070/0001/art5;jsessionid=an2la3spa0n5h.alexandra?format=print Happy modeling! Stephan useR schrieb: Hi R helpers, One rather statistical question? What would be the best startegy to shortlist

Re: [R] pdf creation error

Hi JD, do you have the pdf open in some app, e.g., Acrobat Reader? If the file is open, R can't write on it. My (German) errors in this case look like yours: Fehler in pdf(paste(pic.directory, /full_map.pdf, sep = )) : unable to start device pdf Zusätzlich: Warning message: In

Re: [R] what does negative indexing in a matrix mean?

take all of the matrix *except* those indices, so XW4[,-2] is the matrix XW4 with the 2nd column *deleted*. Cheers, Stephan Itziar Frades Alzueta schrieb: Hi, Does anyone know what the negative indexing of a matrix mean? I am using the RWeka and this evaluate classifier does not work

Re: [R] Omitting a desired line from a table [Beginner Question]

Hi, fish.new - fish[fish$GeoArea==1 fish$Month==10,] HTH, Stephan pfc_ivan schrieb: I am a beginner using this R software and have a quick question. I added a file into the R called fish.txt using this line. fish-read.table(fish.txt, head=T, fill=T) The .txt file looks like this.

Re: [R] Power analysis for MANOVA?

Hi Adam, My (and, judging from previous traffic on R-help about power analyses, also some other people's) preferred approach is to simply simulate an effect size you would like to detect a couple of thousand times, run your proposed analysis and look how often you get significance. In your

Re: [R] Saving plot into file without showing it

Try pdf(foo.pdf) plot(x) dev.off() Other possibilities are jpeg(), tiff(), postscript() etc. HTH, Stephan julien cuisinier schrieb: Hi List, My apologies in advance if question is simplistic, I am quite new to R graphics capabilities and I could not find anything in past threads... I

Re: [R] Get median of each column

Assuming your data are in a data.frame called dataset, apply(dataset,2,median) should work. Look at ?apply HTH, Stephan Frank Zhang schrieb: I am new to R. How can I get column median? Thanks.Frank [[alternative HTML version deleted]]

Re: [R] Power analysis for MANOVA?

. Kramer schrieb: On Mon, 26 Jan 2009, Stephan Kolassa wrote: My (and, judging from previous traffic on R-help about power analyses, also some other people's) preferred approach is to simply simulate an effect size you would like to detect a couple of thousand times, run your proposed analysis and look

Re: [R] Get median of each column

Thank you, Rolf, for this well-deserved spanking :-) I promise to amend my ways and think before I send in the future. Best, Stephan Rolf Turner schrieb: On 29/01/2009, at 8:39 AM, Stephan Kolassa wrote: Assuming your data are in a data.frame called dataset, apply(dataset,2,median

Re: [R] bootstrapping in regression

Hi Thomas, Thomas Mang schrieb: I have a question here: I am not sure if I understand your 'fit the full model ... to the permuted data set'. Am I correct to suppose that once the residuals of the reduced-model fit have been permuted and added back to the fitted values, the values obtained

Re: [R] Matlab inv() and R solve() differences

Hi Cleber, there is no hard-and-fast magic number here. Ill-conditioning also depends on what you are trying to do (inference? prediction?). The condition number is only one of a number of conditioning/collinearity diagnostics commonly used. Take a look at: Golub, G. H., Van Loan, C. F.

Re: [R] A question regarding bootstrap

Hi Erika, the bootstrap is more of a tool to assess variability and create confidence intervals, and people like me prefer permutation tests for testing hypotheses, perhaps something like this: ### sample1 - rnorm(20) sample2 - rnorm(20) n.perms

Re: [R] chi squared goodness of fit test with R

Hi Evrim, chisq.test() performs chi^2 GOF tests. However, the chi^2 test may be sensitive to how you bin your data if you are working with continuous data (as I infer from your mentioning cutting). You may want to look at other GOF tests. Perhaps the NIST statistics is a good starting point:

Re: [R] R system command on windows

?shell HTH, Stephan Aurelie Labbe, Dr. schrieb: Hi, I am trying to use the R command system under windows (XP). If I try the simple command system(mkdir toto) to create a directory toto, it tells me that it cannot find the command mkdir... Does anybody knows how it works ? Is it a path

Re: [R] subset problem (reducing from six to two levels)

Hi, does this help? http://www.nabble.com/factor-question-to18638814.html#a18638814 HTH, Stephan Ine schrieb: Hi all, I have got a seemingly simple problem (I am an R starter) with subsetting my data set, but cannot figure out the solution: I want to subset a data set from six to two

Re: [R] How to comment in R

Hi Mihai, one (very bad style) way would be if (FALSE) { comment comment comment } But putting a # in front of every line is easier to spot in the code. HTH, Stephan mihai.mira...@bafin.de schrieb: Hi everybody, I use for the moment # at the begining of each line for comments. Is

Re: [R] using a noisy variable in regression (not an R question)

Hi Juliet, Juliet Hannah schrieb: One simple thing to try would be to form categories Simple but problematic. Frank Harrell put together a wonderful page detailing all the issues with categorizing continuous data: http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/CatContinuous So:

Re: [R] using a noisy variable in regression (not an R question)

Hi Juliet, Juliet Hannah schrieb: I should have emphasized, I do not intend to categorize -- mainly because of all the discussions I have seen on R-help arguing against this. Sorry that we all jumped on this ;-) I just thought it would be problematic to include the variable by itself. Take

Re: [R] Power calculations where two samples are of unequal size

Hi Farrel, I usually simulate in cases like this - pick the effect size and distributions you conjecture, simulate your data 10,000 times and look how often t.test() gets you a significant difference. Good luck, Stephan Farrel Buchinsky schrieb: I have used the function power.t.test()

Re: [R] Logical inconsistency

Hi Emma, unfortunately, rounding variables before taking the difference will not solve your problem, because the *rounded* variables are subject to the same (effectively) random internal representation. Examples: round(8.3,20)-round(7.3,20)=1 [1] TRUE round(2.3,20)-round(1.3,20)=1 [1]

Re: [R] big data file versus ram memory

Hi Mauricio, Mauricio Calvao schrieb: 1) I would like very much to use R for processing some big data files (around 1.7 or more GB) for spatial analysis, wavelets, and power spectra estimation; is this possible with R? Within IDL, such a big data set seems to be tractable... There are some

[R] Approximate Entropy?

Dear guRus, is there a package that calculates the Approximate Entropy (ApEn) of a time series? RSiteSearch only gave me a similar question in 2004, which appears not to have been answered: http://finzi.psych.upenn.edu/R/Rhelp02a/archive/28830.html RSeek.org didn't yield any results at

Re: [R] Approximate Entropy?

Ben, thanks a lot for that! I have a (reasonably) good idea about what ApEn should be, and I'll try to understand your translation of Kaplan's Matlab code. Best, Stephan Ben Bolker schrieb: Stephan Kolassa wrote: Dear guRus, is there a package that calculates the Approximate Entropy

[R] Logistic regression with rcs() and inequality constraints?

you for your time! Stephan Kolassa __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible

Re: [R] Is there some way to append to a pdf after its device has been closed?

Hi Alex, you can have R execute OS commands using system(), perhaps you can call pdfmerge that way. Or (admittedly less elegantly), you can use LaTeX with the pdfpages package, either using Sweave or system(pdflatex ...). Good luck, Stephan Alex Pine schrieb: Hello all, My question has

[R] Componentwise means of a list of matrices?

Dear useRs, I have a list, each entry of which is a matrix of constant dimensions. Is there a good way (i.e., not using a for loop) to apply a mean to each matrix entry *across list entries*? Example: foo - list(rbind(c(1,2,3),c(4,5,6)),rbind(c(7,8,9),c(10,11,12)))

Re: [R] Componentwise means of a list of matrices?

Statistical Computing Facility Department of Statistics UC Berkeley spec...@stat.berkeley.edu On Tue, 30 Dec 2008, Stephan Kolassa wrote: Dear useRs, I have a list, each entry of which is a matrix of constant

Re: [R] Componentwise means of a list of matrices?

for your help! Stephan Marc Schwartz schrieb: on 12/30/2008 08:33 AM Stephan Kolassa wrote: Dear useRs, I have a list, each entry of which is a matrix of constant dimensions. Is there a good way (i.e., not using a for loop) to apply a mean to each matrix entry *across list entries*? Example: foo

Re: [R] Print specific matrix value???

Hi Nidhi, in your very last line, you set Observed_Scores = GenData[1] After that, Observed_Scores is not a matrix any more, but a list with a single entry Observed_Scores$model, which is in fact a data.frame, but with different dimensions than you initially set Observed_Scores to. HTH,

Re: [R] summary with variance / sd

Hi Jörg, ?by here probably something like by(data=mydata,INDICES=mydata$group, FUN=sd, ...) HTH, Stephan Jörg Groß schrieb: Hi, I have a data frame and would like to have summary statistics for grouped data. With summary() I get the central tendencies for the overall data. How can I

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