similar to: How to speed up a for() loop

Displaying 20 results from an estimated 1000 matches similar to: "How to speed up a for() loop"

2007 Nov 08
1
Bug (?) in read.fwf
Hi, I'm trying to use read.fwf temp = read.fwf ("Raw data.txt", widths = c (11, 21, 10, rep (16, 6)) ,skip = 2, n = 2, stringsAsFactors = FALSE, strip.white = TRUE) but no matter what I do the strings are turned into factors. I believe it's the "n=2" parameter that causes the problem as it seems to work without this. Am I missing something? Thanks in advance,
2008 Aug 11
1
A zoo question / problem
Hi I'm having a problem using the zoo library and I can't see what I'm doing wrong. For example setting up the data > t1 = zoo (matrix (1:12, nrow = 3), order.by = as.Date (c("2008-08-01","2008-08-02","2008-08-03"))) > colnames (t1) = c ("A", "B", "C", "D") > t2 = zoo (matrix (1:12, nrow = 3), order.by =
2010 Oct 28
1
Key combination that removes all R objects
Dear readers, There is a combination of keys that I have (on several occasions now) typed by accident into R (2.10.0) which removes all the objects in the environment, and clears the console, as though I had typed rm(list=ls()). Unfortunately I don't know what the combination of keys are, so I am struggling to find out more about this behaviour on my own and I was hoping that someone has
2007 Feb 05
2
Rconsole - setting the size and location of Windows help files (Rgui)
Hi, Using the Rconsole file I can specify the size and location of the Rgui windows on NT. e.g. # Dimensions (in characters) of the console. rows = 51 columns = 100 How can I specify the size of the help windows that popups when I ask for help? e.g. '?help' I would like the popup window to have say rows = 51 and columns = 100, just like the main window but a different location on the
2010 Oct 27
2
Which version control system to learn for managing Rprojects?
Gabor As someone trying to the rest of my team using Subversion (which I have used for a while, but more as a backup / record of changes), have you a neat / automated way of building a package from a subversion repository? Thanks David Jessop -------------------------- David Jessop Global Head of Quantitative Research UBS Investment Research +44 20 7567 9882 ----- Original Message -----
2010 Oct 13
1
(no subject)
Dear all, I have just sent an email with my problem, but I think no one can see the red part, beacuse it is black. So, i am writing again the codes: rm(list=ls()) #remove almost everything in the memory set.seed(180185) nsim <- 10 mresultx <- matrix(-99, nrow=1000, ncol=nsim) mresultb <- matrix(-99, nrow=1000, ncol=nsim) N <- 200 I <- 5 taus <- c(0.480:0.520) h <-
2010 Oct 13
4
loop
Dear all, I am trying to run a loop in my codes, but the software returns an error: "subscript out of bounds" I dont understand exactly why this is happenning. My codes are the following: rm(list=ls()) #remove almost everything in the memory set.seed(180185) nsim <- 10 mresultx <- matrix(-99, nrow=1000, ncol=nsim) mresultb <- matrix(-99, nrow=1000, ncol=nsim) N
2006 Jul 20
1
Loss of numerical precision from conversion to list ?
I?m working on an R-implementation of the simulation-based finite-sample null-distribution of (R)LR-Test in Mixed Models (i.e. testing for Var(RandomEffect)=0) derived by C. M. Crainiceanu and D. Ruppert. I'm in the beginning stages of this project and while comparing quick and dirty grid-search-methods and more exact optim()/optimize()-based methods to find the maximum of a part of the
2010 Oct 07
3
quantile regression
Dear all, I am a new user in r and I am facing some problems with the quantile regression specification. I have two matrix (mresultb and mresultx) with nrow=1000 and ncol=nsim, where I specify (let's say) nsim=10. Hence, the columns in my matrix represents each simulation of a determined variable. I need to regress each column of mresultb on mresultx. My codes are the following:
2011 Nov 07
1
How do I return to the row values of a matrix after computing distances
## Package Needed library(fields) ## Assumptions set.seed(123) nsim<-5 p<-2 ## Generate Random Matrix G G <- matrix(runif(p*nsim),nsim,p) ## Set Empty Matraces dmax and dmin dmax<- matrix(data=NA,nrow=nsim,ncol=p) dmin<- matrix(data=NA,nrow=nsim,ncol=p) ## Loop to Fill dmax and dmin for(i in 1:nsim) { dmax[i]<- max(rdist(G[i,,drop=FALSE],G)) dmin[i]<-
2007 Oct 11
3
reason for error in small function?
Running the function below, tested using the cardiff dataset from splancs generates the following error. What changes do I need to make to get the function to work? Thanks. --Dale > gen.rpoints(events, poly, 99) > rpoints Error: object "rpoints" not found # test spatial data library(splancs) data(cardiff) attach(cardiff) str(cardiff) events <- as.points(x,y) ###
2006 Mar 08
1
power and sample size for a GLM with Poisson response variable
Craig, Thanks for your follow-up note on using the asypow package. My problem was not only constructing the "constraints" vector but, for my particular situation (Poisson regression, two groups, sample sizes of (1081,3180), I get very different results using asypow package compared to my other (home grown) approaches. library(asypow) pois.mean<-c(0.0065,0.0003) info.pois <-
2007 Dec 04
1
Metropolis-Hastings within Gibbs coding error
Dear list, After running for a while, it crashes and gives the following error message: can anybody suggest how to deal with this? Error in if (ratio0[i] < log(runif(1))) { : missing value where TRUE/FALSE needed ################### original program ######## p2 <- function (Nsim=1000){ x<- c(0.301,0,-0.301,-0.602,-0.903,-1.208, -1.309,-1.807,-2.108,-2.71) # logdose
2009 Sep 02
1
problem in loop
Hi R-users, I have a problem for updating the estimates of correlation coefficient in simulation loop. I want to get the matrix of correlation coefficients (matrix, name: est) from geese by using loop(500 times) . I used following code to update, nsim<-500 est<-matrix(ncol=2, nrow=nsim) for(i in 1:nsim){ fit <- geese(x ~ trt, id=subject, data=data_gee, family=binomial,
2007 Oct 03
2
Speeding up simulation of mean nearest neighbor distances
I've written the function below to simulate the mean 1st through nth nearest neighbor distances for a random spatial pattern using the functions nndist() and runifpoint() from spatsat. It works, but runs relatively slowly - would appreciate suggestions on how to speed up this function. Thanks. --Dale library(spatstat) sim.nth.mdist <- function(nth,nsim) { D <- matrix(ncol=nth,
2012 Nov 23
1
Spatstat: Mark correlation function
I normally use the following code to create a figure displaying the mark correlation function for the point pattern process "A": M<-markcorr(A) plot(M) I have now started to use the following code to perform 1000 Monte Carlo simulations of Complete Spatial Randomness (CSR). It is a Monte Carlo test based on envelopes of the Mark correlation function obtained from simulated point
2010 Nov 08
1
try (nls stops unexpectedly because of chol2inv error
Hi, I am running simulations that does multiple comparisons to control. For each simulation, I need to model 7 nls functions. I loop over 7 to do the nls using try if try fails, I break out of that loop, and go to next simulation. I get warnings on nls failures, but the simulation continues to run, except when the internal call (internal to nls) of the chol2inv fails.
2009 Dec 09
1
Why cannot get the expected values in my function
Hi, In the following function, i hope to save my simulated data into the "result" dataset, but why the final "result" dataset seems not to be generated. #Function simdata<-function (nsim) { result<-matrix(NA,nrow=nsim,ncol=2) colnames(result)<-c("x","y") for (i in 1:nsim) { set.seed(i) result[i,]<- cbind(runif(1),runif(1)) }
2006 Apr 10
1
Generic code for simulating from a distribution.
Hello all, I have the code below to simulate samples of certain size from a particular distribution (here,beta distribution) and compute some statistics for the samples. betasim2<-function(nsim,n,alpha,beta) { sim<-matrix(rbeta(nsim*n,alpha,beta),ncol=n) xmean<-apply(sim,1,mean) xvar<-apply(sim,1,var) xmedian<-apply(sim,1,median)
2011 Apr 07
2
Two functions as parametrs of a function.
Hi R users: I'm trying to make a function where two of the parameters are functions, but I don't know how to put each set of parameters for each function. What am I missing? I try this code: f2<-function(n=2,nsim=100,fun1=rnorm,par1=list(),fun2=rnorm,par2=list()){ force(fun1) force(fun2) force(n) p1<-unlist(par1) p2<-unlist(par2) force(p1) force(p2)