Displaying 20 results from an estimated 1000 matches similar to: "when can we expect Prof Tierney's compiled R?"
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
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,
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
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
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
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 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
2004 Aug 12
9
Giving a first good impression of R to Social Scientists
Dear all,
in the coming Winter Semester, I will be a teaching assistant for a course
in Survival Analysis. My job will be to do the lab sessions. The software
used for these lab sessions will be R. Most of the students have a
background in social sciences and the only stats package they used so far is
most likely SPSS.
So I assume they might be quite surprised the first time they see R
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
2005 Apr 22
1
RE: [R] when can we expect Prof Tierney's compiled R?
If we are on the subject of byte compilation, let me bring a couple of
examples which have been puzzling me for some time. I'd like to know a)
if the compilation will likely to improve the performance for this type
of computations, and b) at least roughly understand the reasons for the
observed numbers, specifically why x[i]<- assignment is so much slower
than x[i] extraction.
The loops
2005 Apr 27
1
RE: [R] when can we expect Prof Tierney's compiled R?
Luke,
Thank you for sharing the benchmark results. The improvement is very
substantial, I am looking forward to the release of the byte compiler!
The arithmetic shows that x[i]<- is still the bottleneck. I suspect that
this is due to a very involved dispatching/search for the appropriate
function on the C level. There might be significant gain if loops
somehow cached the result of the initial
2008 Jan 31
3
fastest way to compute the squared Euclidean distance between two vectors in R
I have a program which needs to compute squared Euclidean distance
between two vectors million of times, which the Rprof shows is the
bottleneck. I wondered if there is any faster way than my own simple
function
distance2 = function(x1, x2)
{
temp = x1-x2
sum(temp*temp)
}
I have searched the R-help archives and can not find anything except
when the arguments are matrices. Thanks for any
2006 Aug 24
4
extremely slow recursion in R?
I recently coded a recursion algorithm in R and ir ran a few days
without returning any result. So I decided to try a simple case of
computing binomial coefficient using recusrive relationship
choose(n,k) = choose(n-1, k)+choose(n-1,k-1)
I implemented in R and Fortran 90 the same algorithm (code follows).
The R code finishes 31 minutes and the Fortran 90 program finishes in 6
seconds. So the
2008 Jul 14
5
A question about using function plot
Hello, everyone! I have spent two hours to get what I wanted in a simple situation and have not been successful. The set up is extremely simple
x = c(1,2,4,8)
y = c(1,2,3,4)
plot(x, y)
What I need, however, is for the 4 points of 1,2,4,8 to be spaced evenly, not by their numerical scale. Also, there should not be any other values such as 5,6,7 marked on the axis.
So I tried the following
x =
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
2007 Feb 21
2
how much performance penalty does this incur, scalar as a vector of one element?
I have been comparing R with other languages and systems. One peculiar feature of R is there is no scalar. Instead, it is just a vector of length one. I wondered how much performance penalty this deign cause, particular in situations with many scalars in a program. Thanks.
Jason Liao, http://www.geocities.com/jg_liao
Associate Professor of Biostatistics
Drexel University School of Public
2001 Apr 17
2
setting up printers with Samba and Windows NT workstation
Hello all.
I'm a samba newbie given the task of setting up samba to act as a print
server for 5 HP laser printers ranging from the LaserJet 4MV to the
LaserJet 8150N. I've done a search of the samba mailing list archives to
see if my problem has already been addressed, but I have been unable to
find anything that refers to the same error I'm receiving. I am using SWAT
to administer
2001 Sep 04
2
fastest way to multiply each column of a matrix by a single vlaue
Let A be a m by n matrix and b a length n vector. What is the fastest
vectorized code for doing
for(j in 1:n) A[, j] <- A[, j]/b[j] ?
solution 1:
t(t(A)/b)
solution 2:
B <- matrix( rep(b, m), byrow=T, nrow=m )
A/B
anything else?
I have a program that uses this kind of operation million of times and
I appreciate your input.
Thanks.
Jason Liao
=====
Jason G. Liao
Department of
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
2005 May 04
1
Cost of method dispatching: was: when can we expect Prof Tierney's compiled R?
> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley@stats.ox.ac.uk]
> Sent: Wednesday, April 27, 2005 1:13 AM
> To: Vadim Ogranovich
> Cc: Luke Tierney; r-devel@stat.math.ethz.ch
> Subject: Re: [Rd] RE: [R] when can we expect Prof Tierney's
> compiled R?
>
> On Tue, 26 Apr 2005, Vadim Ogranovich wrote:
>
...
> > The arithmetic shows