Displaying 20 results from an estimated 1000 matches similar to: "Very Fast Multivariate Kernel Density Estimation"
2004 Jan 09
0
minimization using Powell's method without derivative
Good evening! I have a multi-dimensional minimization problem whose
gradient is pretty hard to code. I tried Nelder and Mead method
implemented in function optim and it does not work well. I also tried
the quasi Newton method in optim using difference as approximate
derivative. It does not work well either. I just went through Numerical
Recipes book. The book discusses another method without
2003 Mar 05
8
how to find the location of the first TRUE of a logical vector
without having to check the vector element by element? Thanks a lot!
Jason
=====
Jason G. Liao, Ph.D.
Division of Biometrics
University of Medicine and Dentistry of New Jersey
335 George Street, Suite 2200
New Brunswick, NJ 08903-2688
phone (732) 235-8611, fax (732) 235-9777
http://www.geocities.com/jg_liao
2002 Oct 30
2
two small wishes for R
1. allows underscore as part of a variable name
2. Uses C or Java style comments mark.
Jason
=====
Jason G. Liao, Ph.D.
Division of Biometrics
University of Medicine and Dentistry of New Jersey
335 George Street, Suite 2200
New Brunswick, NJ 08903-2688
phone (732) 235-8611, fax (732) 235-9777
http://www.geocities.com/jg_liao
__________________________________________________
HotJobs - Search
2003 Jul 26
0
R benchmark, moble Pentium III, 1.13 GHs
Hi Jason,
I suppose you installed the Matrix library, and it is working on your computer? If yes, may be det.Matrix() was removed, or renamed in the Matrix library you have (I cannot check this for the latest version, because I am away of the office until August 1st), but I will do that next week.
In the meantime, you can replace 'det.Matrix' by 'det.default', and it should run.
2003 Jul 23
5
Dismal R performance of Athlon moble CPU?
I have been using a laptop computer of Pentium III 1.13 Ghz. I heard
that AMD's Athlon has excellent floating point capacity. So I bought a
Athlon 2200+ laptop yesterday. I expected that new Athlon 2200+ will be
twice as fast as the P III 1.13 GB. I ran a R simulation program and
the new computer is only 30% faster, in fact slightly slower than a
Celeron 1.50 GB laptop. I am very disappointed
2002 Apr 12
1
summary: Generalized linear mixed model software
Thanks to those who responded to my inquiry about generalized linear
mixed models on R and S-plus. Before I summarize the software, I note
that there are several ways of doing statistical inference for
generalized linear mixed models:
(1)Standard maximum likelihood estimation, computationally intensive
due to intractable likelihood function
(2) Penalized quasi likelihood or similar
2005 Apr 18
2
when can we expect Prof Tierney's compiled R?
I am excited to learn that Prof. Tierney is bringing to us compiled R.
I would like to learn when it will be available. This information will
be useful in scheduling some of my projects. Thanks.
Jason
Jason Liao, http://www.geocities.com/jg_liao
Dept. of Biostatistics, http://www2.umdnj.edu/bmtrxweb
University of Medicine and Dentistry of New Jersey
683 Hoes Lane West, Piscataway‚ NJ 08854
2004 Sep 08
1
64 bit R slower than 32 bit R on Sun Sparc Solaris?
Hello, everyone! I guess no one is still using R on Sun Sparc these
days. But our department has a (pretty new) two-CPU Sun server. We
recently compiled R as a 64 bit application and expected a performance
boost. But it runs 25-30% slower than the 32 bit version of R. Anyone
knows why this is so? Thanks!
Jason
=====
Jason Liao, http://www.geocities.com/jg_liao
Dept. of Biostatistics,
2006 May 10
3
new package error message
My coauthor made a new R package GeneLogit (100% R code) which installs
ok on R 2.3 on Windows. But when I type
library(GeneLogit)
it gave the error message
Error in library(GeneLogit) : 'GeneLogit' is not a valid package --
installed < 2.0.0?
It runs on R 1.9.0 just fine. It seems that others have encountered
same problem but no solution is found by googling
How can I fix this
2002 Aug 06
3
hard to believe speed difference
First, I love R and am grateful to be using this free and extremely
high quality software.
Recently I have been comparing two algorithms and naturally I
programmed in R first. It is so slow that I can almost feel its pain.
So I decided to do a comparison with Java. To draw 500,0000 truncated
normal, Java program takes 2 second and R takes 72 seconds. Not a
computer science major, I find it hard
2002 Apr 01
2
writing a package for generalized linear mixed modesl
Happy new month, everyone!
I am planning to write a NIH grant proposal to study ways to speed
Monte Carlo based maximum likelihood algorithm for hierarchical models
with a focus on generalized linear mixed models (GLM with random
effects). I thought it would be nice and also increase the chance of
funding if I could produce an R package in the process. I understand
that Prof. Pinheiro ang Bates
2005 Jun 15
1
random number generator: same seed used in different sessions
I did several simulation sessions and the result turned out to be a
surprise. After some investigation, I found that different R sessions
of the program used the same seed. Simply, in R210, if I start R and
type rnorm(1), I always get the same random number. This is
contradictary to what is in the R document
Initially, there is no seed; a new one is created from the
current time when one
2001 Dec 19
2
how to get unique vectors
First, happy holidays, everyone! Thanks to the R team for bringing out
1.4 before the new year.
I have 10000 integer triplets stored in A[1:10000, 1:3]. I would like
to find the unique triplets among the 10000 ones with possible
duplications. What is the easiest way for this. I know the function
unique(), which apply to a vector, not the 10000*3 array in my problem.
Thanks in advance.
Jason
2002 Feb 01
4
ROC curves using R
I did some serach around. It seems that ROC curve computation is not
supported on R. Anyone has some leads? Thanks.
Jason
=====
Jason G. Liao, Ph.D.
Division of Biometrics
UMDNJ School of Public Health
335 George Street, Suite 2200
New Brunswick, NJ 08903-2688
phone (732) 235-9748, fax (732) 235-9777
http://www.geocities.com/jg_liao
__________________________________________________
Great
2004 Aug 12
4
truly object oriented programming in R
Good morning! I recently implemented a KD tree in JAVA for faster
kernel density estimation (part of the code follows). It went well. To
hook it with R, however, has proved more difficult. My question is: is
it possible to implement the algorithm in R? My impression seems to
indicate no as the code requires a complete class-object framework that
R does not support. But is there an R package or
2009 May 28
0
Urgent Statistician Position near Philadelphia
Dear R-list,
I know is going to be weird, but I need to do something about and I know
the R-list is big group of good people. I?m moving to Philadelphia in
August 2009 (my fianc? is there) and I need to find a job. I know to do so
many things, but my skill is in science and research. I would like to know
if you know a possible position near Philadelphia, New Jersey or New York.
I was working in
2012 Aug 27
2
randomLCA
Can anybody, please, explain me how many parameter are estimated using
randomLCA?
For examples, model "dentistry.lca2random" estimate 1 scale (or
variance, b_j) parameter and 2 position parameters (a_cj)? Doesn't
it?
Do I need at least 4 diagnostic tests for such a model?
What happens if I specify options blocksize and byclass? How many
diagnostic tests (or rater) I need?
2017 Aug 14
0
tidyverse repeating error: "object 'rlang_mut_env_parent' not found"
The most likely explanation is you have a new version of dplyr/tibble
and an old version of rlang. Try re-installing rlang.
Hadley
On Mon, Aug 14, 2017 at 9:26 AM, Szumiloski, John
<John.Szumiloski at bms.com> wrote:
> UseRs,
>
> When doing some data manipulations using the tidyverse, I am repeatedly getting the same error message in now three separate situations. I can write up
2017 Aug 14
4
tidyverse repeating error: "object 'rlang_mut_env_parent' not found"
UseRs,
When doing some data manipulations using the tidyverse, I am repeatedly getting the same error message in now three separate situations. I can write up a reproducible example, but want to lay out the high-level issues in case someone recognizes exactly what is happening here.
The error is:
Error in mut_env_parent(overscope$.top_env, lexical_env) :
object 'rlang_mut_env_parent'
2017 Aug 14
0
tidyverse repeating error: "object 'rlang_mut_env_parent' not found"
This sounds an awful lot like a bug. Read the Posting Guide to know what to do about bugs. And delaying making the reprex is _always_ a bad idea.
--
Sent from my phone. Please excuse my brevity.
On August 14, 2017 7:26:32 AM PDT, "Szumiloski, John" <John.Szumiloski at bms.com> wrote:
>UseRs,
>
>When doing some data manipulations using the tidyverse, I am repeatedly