Displaying 20 results from an estimated 2000 matches similar to: "boot() with glm/gnm on a contingency table"
2010 Nov 03
3
Using sample() to sample one value from a single value?
Hi, consider this one as an FYI, or a seed for further discussion.
I am aware that many traps on sample() have been reported over the
years. I know that these are also documents in help("sample"). Still
I got bitten by this while writing
sample(units, size=length(units));
where 'units' is an index (positive integer) vector. It works in all
cases as expected (=I expect)
2010 Nov 14
2
jackknife-after-bootstrap
Hi dear all,
Can someone help me about detection of outliers using jackknife after
bootstrap algorithm?
--
View this message in context: http://r.789695.n4.nabble.com/jackknife-after-bootstrap-tp3041634p3041634.html
Sent from the R help mailing list archive at Nabble.com.
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2010 Nov 04
2
How to do bootstrap for the complex sample design?
Hello;
Our survey is structured as : To be investigated area is divided into 6 regions,
within each region, one urban community and one rural community are randomly selected,
then samples are randomly drawn from each selected uran and rural community.
The problems is that in urban/rural stratum, we only have one sample.
In this case, how to do bootstrap?
Any comments or hints are greatly
2005 Nov 29
2
permutation test for linear models with continuous covariates
Hi I was wondering if there is a permutation test available in R for linear
models with continuous dependent covariates. I want to do a test like the
one shown here.
bmi<-rnorm(100,25)
x<-c(rep(0,75),rep(1,25))
y<-rnorm(100)+bmi^(1/2)+rnorm(100,2)*x+bmi*x
H0<-lm(y~1+x+bmi)
H1<-lm(y~1+x+bmi+x*bmi)
anova(H0,H1)
summary(lm(y~1+x+bmi))
But I want to use permutation testing to
2005 Nov 18
3
Method for $
Dear R experts,
I have defined a class "myclass" and would like the slots to be extractable
not only by "@" but also by "$". I now try to write a method for "$" that
simply executes the request object at slotname, whenever someone calls
object$slotname for any object of class "myclass".
I don't manage to find out how I can provide this
2012 May 22
0
dataframe package
A new 'dataframe' package is on CRAN. This is a modified version
of the data frame code in R, modified to make fewer copies of the inputs
and run faster, e.g.
as.data.frame(a vector)
makes 1 copy of the vector rather than 3,
data.frame(a vector)
makes 3 copies rather than 6, and
x[, "a"] <- newValue
makes (2,2,1) copies of (old data frame, new column, integer vector
of
2012 Jun 06
2
suggest that as.double( something double ) not make a copy
I've been playing with passing arguments to .C(), and found that replacing
as.double(x)
with
if(is.double(x)) x else as.double(x)
saves time and avoids one copy, in the case that x is already double.
I suggest modifying as.double to avoid the extra copy and just
return x, when x is already double. Similarly for as.integer, etc.
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2014 Dec 18
8
[LLVMdev] Indexed Load and Store Intrinsics - proposal
Hi,
Recent Intel architectures AVX-512 and AVX2 provide vector gather and/or scatter instructions.
Gather/scatter instructions allow read/write access to multiple memory addresses. The addresses are specified using a base address and a vector of indices.
We'd like Vectorizers to tap this functionality, and propose to do so by introducing new intrinsics:
VectorValue = @llvm.sindex.load
2013 Apr 14
1
R 3.0.0 memory use
I did some benchmarking of data frame code, and
it appears that R 3.0.0 is far worse than earlier versions of R
in terms of how many large objects it allocates space for,
for data frame operations - creation, subscripting, subscript replacement.
For a data frame with n rows, it makes either 2 or 4 extra copies of
all of:
8n bytes (e.g. double precision)
24n bytes
32n bytes
2015 Mar 15
2
[LLVMdev] Indexed Load and Store Intrinsics - proposal
hi Hao,
I started to upstream and the second patch is stalled under review now.
- Elena
-----Original Message-----
From: Hao Liu [mailto:haoliuts at gmail.com]
Sent: Friday, March 13, 2015 05:56
To: Demikhovsky, Elena
Cc: llvmdev at cs.uiuc.edu
Subject: Re: [LLVMdev] Indexed Load and Store Intrinsics - proposal
Hi Elena,
I think such intrinsics are very useful.
Do you have any plan to
2016 Apr 28
2
Why duplicate "protected:" in SmallVector.h, StringMap.h?
In SmallVector.h:
class SmallVectorBase {
*protected:*
void *BeginX, *EndX, *CapacityX;
*protected:*
SmallVectorBase(void *FirstEl, size_t Size)
: BeginX(FirstEl), EndX(FirstEl), CapacityX((char*)FirstEl+Size) {}
In StringMap.h:
class StringMapImpl {
*protected:*
// Array of NumBuckets pointers to entries, null pointers are holes.
// TheTable[NumBuckets] contains a sentinel value
2007 Feb 28
2
sort of OT: bootstrap tutorial
There is now a tutorial on bootstrapping and other resampling
methods at:
http://www.burns-stat.com/pages/Tutor/bootstrap_resampling.html
Corrections and other suggestions are welcome.
The project started because a novice asked me about bootstrapping.
My response was, "How dare you bug me while I'm playing with my
cats, just google for it." My correspondent was not very impressed
2009 Apr 30
0
Categorical variable in a custom nonlin function with gnm
Hi all
I want to construct a generalised nonlinear model (binomial family) using gnm, of the form:
Response = a + b variable1 + c variable2 + d variable3 - d b variable4 - d c variable5,
with the parameters b, c, and d appearing more than once. Hence, I think I need to use a custom nonlin function with gnm.
One of my predictor variables is categorical, so I have created a dummy variable for
2007 Jan 16
1
nonlinear regression: nls, gnls, gnm, other?
Hi all,
I'm trying to fit a nonlinear (logistic-like) regression, and I'd like
to get some recommendations for which package to use.
The expression I want to fit is something like:
y ~ A * exp(X * Beta1) / (1 + exp(-(x + X * Beta2 - xmid)/scal))
Basically, it's a logistic function, but I want to be able to modify
the saturation amplitude by a few parameters (Beta1) and shift the
2009 Apr 06
1
package: maps and spatstat question
I would like to use the output from the map function
in the package maps for use in, say, the spatstat
package. I don't quite understand the coordinates
for the border of the state:
Example:
library(maps)
iowa<-map("region","iowa)
x<-iowa$x
y<-iowa$y
There are NA's and duplicated coordinates.
What would I need to do to use this in the
spatstat owin command?
2010 Feb 17
0
Help with sigmoidal quasi-poisson regression using glm and gnm functions
Hi everyone,
I'm trying to perform the following regressions in order to compare linear
vs. sigmoidal fit of the relationship between my dependent variable (y) and
one explaining parameter (x2), both including the confounding effects of a
third variable (x1):
quasi-pois-lin <- glm(y ~ x1 + x2, family = quasipoisson(link="identity"),
data=fit)
quasi-pois-sig <- gnm(y ~ x1 +
2012 Apr 02
0
gnm and gnlr3
Hi,
I am quite new to R and would like to do nonlinear regressions with
Poisson distributed data.
I would like to estimate paramters of an equation of this type:
FR = [c*NO * exp(a+b*NO)] / [(c+NO)*(1+exp(a+b*NO))]
a,b and c are parameters, NO are input values
I found both the gnm and gnlr3 function which should be able to do this
regression but I can't manage to make it work.
How can I
2007 Jan 26
1
bootstrap bca confidence intervals for large number of statistics in one model; library("boot")
Sometimes one might like to obtain pointwise bootstrap bias-corrected,
accelerated (BCA) confidence intervals for a large number of statistics
computed from a single dataset. For instance, one might like to get
(so as to plot graphically) bootstrap confidence bands for the fitted
values in a regression model.
(Example: Chiu S et al., Early Acceleration of Head Circumference in
Children with
2014 Dec 21
3
[LLVMdev] Indexed Load and Store Intrinsics - proposal
On 12/18/2014 11:56 AM, dag at cray.com wrote:
> "Demikhovsky, Elena" <elena.demikhovsky at intel.com> writes:
>
>> Semantics:
>> For i=0,1,…,N-1: if (Mask[i]) {*(BaseAddr + VectorOfIndices[i]*Scale)
>> = VectorValue[i];}
>> VectorValue: any float or integer vector type.
>> BaseAddr: a pointer; may be zero if full address is placed in the
2008 Jul 01
1
[.data.frame speedup
Below is a version of [.data.frame that is faster
for subscripting rows of large data frames; it avoids calling
duplicated(rows)
if there is no need to check for duplicate row names, when:
i is logical
attr(x, "dup.row.names") is not NULL (S+ compatibility)
i is numeric and negative
i is strictly increasing
"[.data.frame" <-
function (x, i, j,