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)