Displaying 20 results from an estimated 1000 matches similar to: "parallel bootstrap linear model on multicore mac"
2011 Feb 24
1
parallel bootstrap linear model on multicore mac (re-post)
Hello all,
I am re-posting my previous question with a simpler, more transparent,
commented code.
I have been ramming my head against this problem, and I wondered if
anyone could lend a hand. I want to make parallel a bootstrap of a
linear mixed model on my 8-core mac. Below is the process that I want to
make parallel (namely, the boot.out<-boot(dat.res,boot.fun, R = nboot)
command).
2012 Aug 09
0
RMySQL dbConnect issues
Hello,
I have access to my database via command line and through workbench, and
have access on the grant tables:
mysql> SELECT host,user,password,select_priv,insert_priv FROM user;
+------+-------+-------------------------------------------+-------------+-------------+
| host | user | password | select_priv
| insert_priv |
2010 Aug 25
2
Problem with clusterCall, "Error in checkForRemoteErrors(lapply(cl, recvResult)) : "
Hi all,
I am trying to use snow package to do a parallel MCMC. I have read a few
guides and articles, the following is that I came up with.
When I run it I got the error message:
Error in checkForRemoteErrors(lapply(cl, recvResult)) :
4 nodes produced errors; first error: could not find function "ui.Next"
The data is a longitudinal data with few repeated readings on a number of
2010 Jul 20
1
p-values pvclust maximum distance measure
Hi,
I am new to clustering and was wondering why pvclust using "maximum"
as distance measure nearly always results in p-values above 95%.
I wrote an example programme which demonstrates this effect. I
uploaded a PDF showing the results
Here is the code which produces the PDF file:
-------------------------------------------------------------------------------------
s <-
2009 Jan 14
3
remove columns containing all zeros (or other value)
Hello-
I would like to remove the columns of a matrix that contain all zeros.
For example, from
x<-matrix(c(1,5,3,2,1,4,0,0,0), ncol=3,nrow=3)
I would like to remove the third column. However, because this is in a
loop I need a way to first determine which columns are all zeros, and
only then remove them. I.e., I don't know which column of x contains all
zeros until after x is
2011 May 16
1
Matrix manipulation in for loop
Hi all,
I have a problem with getting my code to do what I want!
This is the code I have:
create.means.one.size<-function(nsample,var,nboot){
mat.x<-matrix(0,nrow=nboot,ncol=nsample)
for(i in 1:nboot){
mat.x[i,]<-sample(var,nsample,replace=T)
}
mean.mat<-rep(0,nboot)
for(i in 1:nboot){
mean.mat[i]<-mean(mat.x[i,])
}
sd.mean<-sd(mean.mat)
return(mean.mat)
}
where
2012 Jan 19
1
snow - bootstrapped correlation ranking
I wonder if someone could help me adjusting the following code to parallelized snow code:
#Creating a data set (not needed to be parallel)
n<-100
p<-100
x<-matrix(rnorm(n*p),p)
y<-rnorm(n)
# Bootstrapping
nboot<-1000
alpha<-0.05
rhoboot <- array(0, dim=c(p,nboot))
bootranks <- array(0, dim=c(p,nboot))
bootsamples <- array( floor(runif(n*nboot)*n+1), dim=c(n,nboot))
for
2009 Jan 06
1
R SEM package
Does anyone know if the sem package in R can implement a stacked model
comparison, for example as in LISREL or AMOS?
Thanks,
Anthony
--
Anthony Steven Dick, Ph.D.
Post-Doctoral Fellow
Human Neuroscience Laboratory
Department of Neurology
The University of Chicago
5841 S. Maryland Ave. MC-2030
Chicago, IL 60637
Phone: (773)-834-7770
Email: adick at uchicago.edu
Web:
2009 Jan 26
1
sem package: start values
Hello-
If I input a variance-covariance matrix and specify NA for start values,
how does sem determine the start value? Is there a default?
Anthony
--
Anthony Steven Dick, Ph.D.
Post-Doctoral Fellow
Human Neuroscience Laboratory
Department of Neurology
The University of Chicago
5841 S. Maryland Ave. MC-2030
Chicago, IL 60637
Phone: (773)-834-7770
Email: adick at uchicago.edu
Web:
2010 May 25
1
SEM interaction
Hello all,
This is a general stats question--I realize it is an R help list, so
tell me to go away if it is inappropriate.
I have a 2 X 2 design, and I have specified four identical path models
(one for each level of each factor). I want to test for an interaction
at each path--essentially (A1 - A2) - (B1 - B2) != 0. I was thinking of
computing a contrast for each path of interest, such that
2006 Oct 23
1
Lmer, heteroscedasticity and permutation, need help please
Hi everybody,
I'm trying to analyse a set of data with a non-normal response, 2 fixed
effects and 1 nested random effect with strong heteroscedasticity in the
model.
I planned to use the function lmer : lmer(resp~var1*var2 + (1|rand)) and
then use permutations based on the t-statistic given by lmer to get
p-values.
1/ Is it a correct way to obtain p-values for my variables ? (see below)
2007 Nov 01
1
loops & sampling
Hi,
I'm new to R (and statistics) and my boss has thrown me in the deep-end with the following task:
We want to evaluate the impact that sampling size has on our ability to create a robust model, or evaluate how robust the model is to sample size for the purpose of cross-validation i.e. in our current project we have collected a series of independent data at 250 locations, from which
2009 Feb 02
1
sem package and AMOS
Hello-
I am using R to build my initial models, but need to use AMOS to compare
the models of two groups (adults vs. kids). The problem is I am getting
different results with R and AMOS for the initial models of the separate
groups (and the R results make more sense).
The parameter estimates (path coefficients and variances) from both
programs are nearly identical, but the model chi-squares
2018 May 22
0
Bootstrap and average median squared error
Hello,
If you want to bootstrap a statistic, I suggest you use base package boot.
You would need the data in a data.frame, see how you could do it.
library(boot)
bootMedianSE <- function(data, indices){
d <- data[indices, ]
fit <- rq(crp ~ bmi + glucose, tau = 0.5, data = d)
ypred <- predict(fit)
y <- d$crp
median(y - ypred)^2
}
dat <-
2013 Sep 26
0
R hangs at NGramTokenizer
Hi:
I try to construct a Document-Term Meatrix from a corpus. The commands I used are:
> library(parallel)> library(tm)> library(RWeka)> library(topicmodels)> library(RTextTools)> cl=makeCluster(detectCores())> invisible(clusterEvalQ(cl, library(tm)))> invisible(clusterEvalQ(cl, library(RWeka))) > invisible(clusterEvalQ(cl, library(topicmodels)))>
2006 Nov 23
2
loading libraries on MPI cluster
Dear R-users,
we are using library(snow) for computation on a linux cluster with RMPI.
We have a problem with clusterEvalQ: after launching clusterEvalQ it seems
loading the required library on each node but if we type a function
belonging to the loaded package R doesn't find it.
> library(snow)
# making cluster with 3 nodes
> cl <- makeCluster(3, type = "MPI")
Loading
2020 Nov 04
0
parallel PSOCK connection latency is greater on Linux?
Please, check a tcpdump session on localhost while running the following script:
library(parallel)
library(tictoc)
cl <- makeCluster(1)
Sys.sleep(1)
for (i in 1:10) {
tic()
x <- clusterEvalQ(cl, iris)
toc()
}
The initialization phase comprises 7 packets. Then, the 1-second sleep
will help you see where the evaluation starts. Each clusterEvalQ
generates 6 packets:
1. main ->
2018 May 22
2
Bootstrap and average median squared error
I forgot, you should also set.seed() before calling boot() to make the
results reproducible.
Rui Barradas
On 5/22/2018 10:00 AM, Rui Barradas wrote:
> Hello,
>
> If you want to bootstrap a statistic, I suggest you use base package boot.
> You would need the data in a data.frame, see how you could do it.
>
>
> library(boot)
>
> bootMedianSE <- function(data,
2011 Apr 03
2
:HELP
Hello,
I want to sum first three terms of each column of matrix.
But I don't calculate with "apply" function.
skwkrt<-function(N=10000,mu=0,sigma=1,n=100,
nboot=1000,alpha=0.05){
x<-rnorm(N,mu,sigma)#population
samplex<-matrix(sample(x,n*nboot,replace=T),nrow=nboot)
#...
}
is that: suppose a is a 5x2 matrix.
a={1,2,3,4,5
2018 May 21
2
Bootstrap and average median squared error
Dear R-experts,
I am trying to bootstrap (and average) the median squared error evaluation metric for a robust regression. I can't get it. What is going wrong ?
Here is the reproducible example.
#############################
install.packages( "quantreg" )
library(quantreg)
crp <-c(12,14,13,24,25,34,45,56,25,34,47,44,35,24,53,44,55,46,36,67)
bmi