Displaying 20 results from an estimated 500 matches similar to: "Bootstrapping nlme models"
2012 Apr 12
5
Organizations where IT has approved the use of R software
Hi Gang,
I realize this post is not directly related to programing issues with R,
however, it appears this may be the best place to ask my question.
I am putting forward a request that R be considered "approved" software in
my organization. Never an easy task, this is made much more difficult given
that it is open source software (sends the IT gang into little fits). So, I
am
2009 Mar 02
2
logistic regression model validation through bootstrapping
Hi,
I was wondering whether this query was addressed on how to perform
validation through boostrapping. I am currently trying to implement a
boostrapping approach to validation but don't know where to start. Help
please.
Thank you and Regards,
Vivienne Ozohili
Risk Model Validation Manager
Group Risk
Independent Control Unit
A5, Bank of Ireland Head Office
Lower Baggot Street
Dublin 2
Tel:
2008 Sep 10
1
bootstrapping - number of items to replace is not a multiple of replacement length
Hello,
I'm new to boostrapping and I'd need some help to understand the error
message that pops up when I run my script.
I have a data.frame with 73 lines and 21 column.
I am running a stepwise regression to find the best model using the R
function "step".
I apply bootstrapping to obtain model coefficients.
This is my script:
# "datare80" is the name of the
2012 Nov 20
1
parApply computing
I'm using /parApply/() function in "snow" package for parallel computing
(boostrapping repeating calculation), as the follows:
MyBoostrapping <- function( i ){
.....
}
cl <- makeCluster( ncluster, type = "SOCK")
i.circle <- as.matrix( 1:128, , 1)
parApply( cl, i.circle, 1, FUN = MyBoostrapping)
It works.
However, I want to set more than one arguments to
2010 Jan 21
1
Estimation of S.E. based on bootstrapping (functions with two or more arguments)
Hi all,
I need to estimate S.E. of a certain indicator. The function to compute the
value of indicator contains two arguments. Can anybody tell me how to do it?
Example:
We have data:
a <- c(1:10)
b <- c(11:20)
data <- data.frame(a, b)
Function to compute value of the indicator:
indicator <- function(X, Y) sum(X)/(sum(Y)*2)
Next I need to do the
2008 Jun 25
0
pvclust:a general and a specific question
I realize questions about packages should go to the package maintainer,
but perhaps I have an old email address (suzuki3 at is.titech.ac.jp)
Also I have both a general, and a specific, question.
1) General question: i've used pvclust before to assess significance of
clusters and got reasonable results. However, on a new data set (see
below) the results seem odd. I wonder if pvclust is a
2009 Jul 01
0
double bootstrap
Hi All,
I would like to do double boostrapping to estimate 95% CI coverage.
So, I can only need to estimate 95% confidence interval from each
bootstrapped sample.
Since we don't have a closed form of 95% CI, in order to get 95% CI for each
sample, we need to use bootstrapping.
For outer bootstrapping, I used boot function in library(boot).
How can I add double bootstrap inside the function.
2007 Nov 20
1
Problem with code for bootstrapping chi square test with count data
Hi,
I'd like some advice on bootstrapping in R.
I have a species x with 20 individuals and a factor containing 0 and 1's
(in this case 5 zeros and 15 ones). I want to compare the frequency of
the occurrence of 1 with a probability value. This code seems to work to
do this in R.
attach(test)
p <- c(0.5272, (1-0.5272))
sp1_1 <- length(subset(x, x==1))
sp1_0 <- length(subset(x,
2009 May 26
0
Bootstrapping and estimation of standard error
Hello,
I've started using R few months ago and I really like it.
I need to estimate standard deviation of certain statistics (some
measures of poverty). I found a really simple program, and I just need
to check whether it's OK and really calculates what it's supposed to.
Let's suppose e. g. head-count index (as one of the simplest measures of
poverty) which is calculated as a
2016 Oct 17
3
unable to compile llvm with gcc 4.7.4
On Mon, Oct 17, 2016 at 11:28 AM, Renato Golin via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> On 17 October 2016 at 19:09, Flamedoge via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> > Just for the interest of discussion, I find it completely weird and
> > interesting that GCC needs to build itself 3 times to fully bootstrap.
> Has
> > there been any
2007 Feb 23
1
Bootstrapping stepAIC() with glm.nb()
Dear all,
I would like to Boostrap the stepAIC() procedure from package MASS for
variety of model objects, i.e.,
fn <- function(object, data, B = 2){
n <- nrow(data)
res <- vector(mode = "list", length = B)
index <- sample(n, n * B, replace = TRUE)
dim(index) <- c(n, B)
for (i in 1:B) {
up.obj <- update(object, data = data[index[, i], ])
2016 Jul 30
0
strange behavior in 'inherits' check for loaded S4 object
>>>>> Kevin Ushey <kevinushey at gmail.com>
>>>>> on Fri, 29 Jul 2016 11:46:19 -0700 writes:
> I should add one more item that may be related here --
> calling 'methods:::.requirePackage' returns a different
> result based on whether the package namespace is already
> loaded or not.
> If the package namespace is
2012 Oct 08
0
Mininum number of resamples required to do BCa bootstrap?
I'm using R 2.15.1 on a 64-bit machine with Windows 7 Home Premium
and package 'boot'.
I've found that using a number of bootstrap resamples in boot() that
is less than the number of data results in a fatal error. Once the
number of resamples meets or exceeds the number of data, the error disappears.
Sample problem (screwy subscripted syntax is a relic of edited down a
more
2006 Jan 11
0
Permutation columns or boostrapping
Hi,
I want to permutate the following matrix and replace permutated columns. Is
it possible to control the number of columns permutated. Let's say I only
want to permute two columns. Can i do that with the sample method or should
i any bootstrapping method ?? I'm not sure this is the best statisticaly
way of doing it...??
So the idea behind is to ramdonly generate 1000 permutated
2006 Dec 11
0
double boostrap with clusterApplyLB
Dear R-Users,
we are using a linux-cluster with RMPI and the snow package.
We would like to do a double boostrap.
We have a general function that implements the first boostrap (the outer) and
we are wondering if we can include another bootstrap (the inner) in the
same general function including another clusterApplyLB.
For example:
general function = function(...) {
clusterApplyLB(cl,
2012 Oct 02
0
Possible error in BCa method for confidence intervals in package 'boot'
I'm using R 2.15.1 on a 64-bit machine with Windows 7 Home Premium.
Sample problem (screwy subscripted syntax is a relic of edited down a
more complex script):
> N <- 25
> s <- rlnorm(N, 0, 1)
> require("boot")
Loading required package: boot
> v <- NULL # hold sample variance estimates
> i <- 1
> v[i] <- var(s) # get sample variance
>
2016 Aug 02
0
strange behavior in 'inherits' check for loaded S4 object
Hi Martin, John,
Thanks for the responses! I've tidied up some of the notes from this
mailing list thread and posted them on the bug tracker.
John, in this case, I think namespaces are relevant because for
non-exported S4 classes, the class information is made available
through the '.__C__<package>' symbol in the package's namespace, but
not the package environment that
2010 Jul 12
1
Robust regression error: Too many singular resamples
Hello.
I've got a dataset that may have outliers in both x and y. While I am not
at all familiar with robust regression, it looked like the function lmrob in
package robustbase should handle this situation. When I try to use it, I
get:
Too many singular resamples
Aborting fast_s_w_mem()
Looking into it further, it appears that for an indicator variable in one of
my interaction terms, 98%
2012 Dec 18
0
R function for computing Simultaneous confidence intervals for multinomial proportions
Dear all,
Does someone know an R function implementing the method of Sison and
Glaz (1995) (see full ref below) for computing Simultaneous confidence
intervals for multinomial proportions?
As alternative method, I think to boostrap the mean of each proportion
and get in that way confidence interval of the mean.
I observed 21 times a response that could be one out of 8 categories
2013 Feb 07
1
Saving model and other objects from caret
Say I train a model in caret, e.g.:
RFmodel <- train(X,Y,method='rf',trControl=myCtrl,tuneLength=1)
How can I save this to disk and load it later in R?
How about an object of the class "resamples"?
resamps <- resamples(
list( RF = RFmodel,
SVM = SVMmodel,
KNN = KNNmodel,
NN = NNmodel
))
Thanks,