similar to: Symbolic math?

Hello to everyone, I have 2 problems and would be very pleased if anyone can help me: 1) When I use the package "systemfit" for SUR regressions, I get two different variance-covariance matrices when I firstly do the SUR regression ("The covariance matrix of the residuals used for estimation") and secondly do the OLS regressions. In the manual for "systemfit" on page

Hi, I have a vector, which contains both strings and numbers, e.g. > foo <- c("str1",1234,"str2",0.9876) I want to know if a distinct element of the vector is a string or a number and took "is.numeric", but > is.numeric(foo[2]) [1] FALSE because R treats the numbers in a mixed vectors as strings: > foo [1] "str1" "1234"

Hi, I have a dataframe (say myData) and want to get a list (say myList) that contains a matrix for each row of the dataframe myData. These matrices are calculated based on the corresponding row of myData. Using a for()-loop to do this is very slow. Thus, I tried to use apply(). However, afaik apply() does only return a list if the matrices have different dimensions, while my matrices have

Is there a package in R that handles general linear (in-)equality + box constrained optimization? If it is not there, could anyone advise me which way to go? And/or point me to packages that solve these problems partially? best, ingmar -- Ingmar Visser Department of Psychology, University of Amsterdam Roetersstraat 15, 1018 WB Amsterdam The Netherlands http://users.fmg.uva.nl/ivisser/ tel:

Hi there, I need to plot an illustrative figure without ticks, x, y labels in R. I managed to get the ticks removed, but had no luck with x, y labels. Any suggestions would be much appreciated. Jin Li [[alternative HTML version deleted]]

Dear R Users: The functions of our "micEcon" package [1,2] can be subdivided into three categories: - microeconomic demand and firm models - sample selection models (mainly selection()) - routines for (likelihood) maximisation (e.g. maxLik(), maxNR(), maxBHHH()) (mainly used for ML estimation of sample selection models) Although sample selection models are often used in

Hi Folks, How do I get red bold font on my y axis and black standard font on my x axis? plot(runif(10), ylab="Red, Bold?", xlab="Black, standard?") Any pointers or examples would be great. Thanks! Hank Dr. Hank Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243

Hi All, I am running R 2.2.0 on Mac OS 10.4.2, dual G5 processors with 8 Gig RAM. I am running a simulation with lsoda that requires ~378 s to complete one set of time intervals. I need to optimize the parameters, and so need to considerably speed up the simulation. I have tried to figure out how to change the appropriate memory allocation and have search R help and Introductory

Hello I know how read a file in excel format into a R data frame using the RODBC library, but I don't know how write a R data frame in excel format. I don't understand the instructions from RODBC user manual. To read an excel file I use. library(RODBC); conex<-odbcConnectExcel("fis_quim.xls"); sqlTables(conex); data<-sqlFetch(conex,"hoja1"); Suppose I

Hi, I was really happy when I saw that in R version 2.3.0 "R CMD check" works for packages whose package name is different from the directory name in which it is located (see http://cran.r-project.org/src/base/NEWS). Now, I can have branches of my packages in directories like "[...]/branches/<version number>/", while I had to use "[...]/branches/<version

I was trying to help someone who used a spanish keyboard on a PC running Windows. he discovered that he had no tilde key. Does anyone know of any simple work-arounds? Thanks, Hank Dr. Hank Stevens, Associate Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.cas.muohio.edu/~stevenmh/

My apologies in advance for my thickness but I can't seem to solve the following, seemingly simple, data manipulation problem: I have a data frame that contains multiple factors and multiple continuous response variables, but duplicates of some factor combinations. The duplicates contain bad data, so I would like to eliminate the duplicates. I would like to retain the entire rows

How do I cite a package (not R itself - I know how to do that)? Any thoughts or links? Many thanks in advance? Hank Stevens Dr. Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243 http://www.cas.muohio.edu/botany/bot/henry.html http://www.muohio.edu/ecology/

R v. 1.7.1, Windows 2000. A particular journal wants me to provide scatter plots with no box, but with axes that meet in the lower left corner. It seems as though there must be an easy way of doing this, but my reading the help on plot.default, axis, and box have not provided any clues. I would be most appreciative of any feedback. Thank you, Hank Stevens Dr. Martin Henry H. Stevens,

Hi Folks, I was wondering what everyone thought about adding a sentence to each package update announcement that described what the package did. R extensions are so numerous that it is difficult to keep up with them. Would it be appropriate to ask package developers to add a brief sentence about what the package does, when they announce updates? I would benefit from such descriptions.

Dear All, I would like to publish a function for 'heckit' estimations together with two examples from Greene's and Wooldridge's econometric textbooks. These examples use the dataset of Mroz (1987) that is also available in John Fox' "car" package. However, not all variables that are used in my examples are available in the "car" package. Therefore, I

Hi - I am getting different results when I run the numerical integrator function lsoda (odesolve package) on a Mac and a PC. I am trying to simulating a system of 10 ODE's with two exogenous pulsed inputs to the system, and have had reasonably good success with many model parameter sets. Under some parameter sets, however, the simulations fail on the Mac (see error message below). The

Hi, I added a new function "predict.systemfit" to our package "systemfit" to make it closer to other packages (e.g. lm). Now "R CMD check" complains that the generic function "predict" has only the argument "object", while our function "predict.systemfit" has more arguments. However, the function "predict.lm" has also more

Using R v. 1.7.0 on Windows 2000 I would like to plot the fitted values of a model as a function of a continuous covariate, augmented with data (e.g., augPred) grouping by combinations of fixed effects. I have not been able to use augPred effectively, and am wondering if it does not handle unbalanced data (3 out of 192 missing). I include below the model and an xyplot that almost does the

Hi there fellow R-users, Im seeing some strange behaviour when I multiply a vector by a matrix Here is my script: > tr 1 2 3 4 5 6 0.2217903 0.1560525 0.1487908 0.1671354 0.1590643 0.1471667 > > ex1 a b c d e f 1 0.2309579 -3.279045 -0.6694697 -1.1024404 0.2303928 -1.5527404 2