similar to: Simulating Gaussian Mixture Models

Dear R experts, i have a vector z , i have to do something after z is sorted. how can i find the original index, i.e., before sorting, of a certain element in the sorted vector . thanks in advance regards ----------------------------------------------- Peng Jiang ?? ,Ph.D. Candidate Antai College of Economics & Management ???????? Department of Mathematics ??? Shanghai Jiaotong

Hi, dear R experts . is there any package contain an universal EM procedure, that is , for arbitrary d.f. , not just the one in mclust . thanks in advance best regards ----------------------------------------------- Peng Jiang ?? ,Ph.D. Candidate Antai College of Economics & Management ???????? Department of Mathematics ??? Shanghai Jiaotong University (Minhang Campus) 800 Dongchuan Road

Hi, dear R experts , I am new. I met this problem when I am trying to learn how to use the nlminb() function. I tried the example which the document provides ( as the following code ) and R gives no response . I don't know whether it is running or not and it takes a very long time but still output nothing so I just close the session window. my question is is there any method

Hi,Dear all R experts, I am trying to do the 2-way contingency table analysis by fitting the loglinear models. However, I found my table has several empty cells which are theoretically missing values.I have no idea of how to solve them coz we cannot compute the simulated p-value with zero marginals.Does someone have some suggestions? Please help me out, thanks a lot! Cheers, Yan

Hi all, I am a biological student and need your help in statistics. I have two sets of binomial distributed numbers: {a1, a2, ..., an} and {b1, b2, ..., bn}. How can I get the distribution of the ratios of the two sets of numbers {a1/b1, a2/b2, ..., an/bn}? Is there a formula to transform the distributions? Or where I can start if I want to learn necessary techniques? Thank you a lot! xiechao

Hi, Is the following function built in somewhere? concat = function(v) { res = "" for (i in 1:length(v)) res = paste(res,v[i],sep="") res } e.g. > concat(c("12","3","45")) [1] "12345" Cheers, Andy -- Andy Fugard, Postgraduate Research Student Psychology (Room F3), The University of Edinburgh, 7 George

I'm trying to do realize the following: I have 4 condtions. If all conditions are satisfied I will paste("PASS") If any of these is not satisfied I will paste("FAIL"). But I have to paste the corresponding failure. ifelse is a good solution but for a 2 conditions. Maybe switch or something like this. Does anyone have an idea how to do? Thanks in advance. Adel -- View

Hello there. Is there any function in R that can do cluster on a set of data that has both categorical and numerical variables? thanks. siangli

Hello. Somebody knows how can I generate a set of n random vectors of a normal distribution of several variables? For example, I want to generate n=100 random vectors of two dimensions for a normal with mean c(0,1) and variance matrix: matrix(c(2,1,1,3),2,2). Thanks in advance, Arnau.

Dear R Users, I would like to plot three time series on the same graph, two axis on the left and one axis on the right. The time series that I am graphing on the left do not share a similar scale: one has a range of 1:100 and the other a range of 25000:70000. How can I display the tick marks for both on the left hand side without superimposing them, i.e. one set of tick marks in black right

Dear helpers, I wrote a code which estimates a multi-equation model with generalized least squares (GLS). I can use GLS because I know the covariance matrix of the residuals a priori. However, it is a bit slow and I wonder if anybody would be able to point out a way to make it faster (it is part of a bigger code and needs to run several times). Any suggestion would be greatly appreciated. Carlo

Is there an element-by-element multiplication in R, like the .* operator in Matlab? eg: A (2x3) B (2x3) C=A.*B C (2x3) C = [[a11*b11 a12*b12 a13*b13]; [a21*b21 a22*b22 a23*b23]] I can't find one... Thanks -Mike Gates

Hi, I first report the installing error to the r-sig-mac mailing list but it seems nobody ever encounter this annoying problem and I got no replies. so I am trying to forward it to this list, hope it never bothers. Anyone had the same problem, or what does the warning message mean ? Thank you in advance ! Begin forwarded message: > From: Peng Jiang <jp021@sjtu.edu.cn> > Date:

Dear all: I'm trying to fit the optimal Box-Cox transformation related to nls (see the code below) for the demand of money data in Green (3th Edition) but in the last step R gives the next error message. Error en `[.data.frame`(eval(object$data), , as.character(formula(object)[[2]])[2]) : undefined columns selected. ?Any idea to solve the problem? Thanks in advance,

Hi All I am having 2 very long character strings (550chars) and I want to put them as expressions together with c(). The problem is that I also get these double-quotes, as seen below in 'fct'. How can I remove these double-quotes? I tried as.name() but it did not work (because of size?). These are creating trouble with subsequent programs, which I tested with strings that for some

Dear R buddies, This weekend I became interested in solving Google Code Jam problems using R. I guess R may work very well in this kind of contests but the input of file has been a problem for me. Take this case for example (http://code.google.com/codejam/contest/dashboard?c=agdjb2RlamFtchALEghjb250ZXN0cxjRzBQM), the files are usually of the form: A(number of lines for group 1) a11 a12 a13 a21

I am fitting models to the responses to a questionnaire that has seven yes/no questions (Item). For each combination of Subject and Item, the variable Response is coded as 0 or 1. I want to include random effects for both Subject and Item. While I understand that the datasets are fairly small, and there are a lot of invariant subjects, I do not understand something that is happening

Dear R listers, I know I'm breaking the rules by asking a "homework" related question-- I hope you'll forgive me. I am a social psychology graduate student, and the only one in my department who uses R. I successfully completed my multiple regression and structural equation modeling courses using R (John Fox's car and sem packages were a big help, as was his book).

r-devel list, I have recently written an R package that solves a linear least squares problem, and computes the multivariate normal density function. The bulk of the code is written in C, with interfacing code to the BLAS and Lapack libraries. The motivation here is speed. I ran into a problem computing the determinant of a symmetric matrix in packed storage. Apparently, there are no explicit

Is there a way to generate identical random samples using R's runif function and SAS's ranuni function? I have assigned the same seed values in both software packages, but the following results show different results. Thanks! R === > set.seed(6) > random <- runif(10) > random [1] 0.6062683 0.9376420 0.2643521 0.3800939 0.8074834 0.9780757 0.9579337 [8] 0.7627319 0.5096485