Displaying 20 results from an estimated 80000 matches similar to: "How to search an element in matrix ?"
2007 Feb 02
2
A question about dput
Hi,
I am trying to output a R data set for use in WinBugs, I used
dput(list(x=rnorm(100),N=100),file="bug.dat")
But I can't get the intended format: list(x=c(.......),N=100), instead, I got
something like this (copied the first two lines):
[00000000]???73?74?72?75??63?74?75?72??65?28?6C?69??73?74?28?78???? structure(list(x
2005 Jun 28
2
How to import data as numeric array?
Did some search but couldn't find useful result.
I am trying to read a n*m dimension data with read.table, what i need is a numeric array,
is there any efficient way to allow me get this array directly instead of a list?
I tried to use as.array() to change the mode, but seems it doesn't work and i got this error message:
"Error in "dimnames<-.data.frame"(`*tmp*`,
2007 Jan 09
4
A question about R environment
Hi all,
I created environment "mytoolbox" by : mytoolbox <- new.env(parent=baseenv())
Is there anyway I put it in the search path ?
If you need some background :
In a project, I often write some small functions, and load them into my workspace directly, so when I list the objects
with ls(), it looks pretty messy. So I am wondering if it is possible to creat an
2006 Sep 27
2
How to pass expression as an argument
Hi,
I am writing a function and need to pass a function expression as an argument, for instance,
myfun <- function( express) {
x<- c(1,2,3)
y<-express
}
if I call the above function by myfun( x*2 ), I get 2 as the result, instead of 2,4,6 , could someone help me to
fix this problem ?
Furthermore, is that
2007 Jan 14
1
Questions about paste and assign
Hi,
I would like to assign a value to a member b of the list a in position 3, by calling:
assign( target, 2.34, 3)
My question is what the "target" should be. I tried target <- paste("a", $, "b") and something else,
but haven't got the right answer yet.
BTW, if I attached a list named
2007 Apr 01
1
Keep R packages in the R installation
Hi,
I just got a quick question here, when I install a new version of R , is there an easy to keep the installed R packages ?
Thanks a lot for any help.
tong
2007 Apr 02
2
Compiling C codes in Windows
Hi All,
I have been struggling to figure out how to compile c codes for R use. I am using Win XP + Cygwin + R binaries.
After I followed all the instructions in " Building R for Windows" from Murdoch's website, I tried to Run something like :
R CMD SHLIB C:\R\test.c , but still didn't get any output.
My first question is, does this mean I already did
2007 Apr 02
2
Compiling C codes in Windows
Hi All,
I have been struggling to figure out how to compile c codes for R use. I am using Win XP + Cygwin + R binaries.
After I followed all the instructions in " Building R for Windows" from Murdoch's website, I tried to Run something like :
R CMD SHLIB C:\R\test.c , but still didn't get any output.
My first question is, does this mean I already did
2007 Apr 03
3
Strange number produced by dnorm
Hi All,
I just started to learn compiling C codes for R usage, and got a problem when I was playing with my 'hello world' code.
#include <R.h>
#include <Rdefines.h>
#include <Rmath.h>
SEXP test( ) {
double x;
x=dnorm(1.0,0.0,1.0,1);
printf(" x value is: %d \n",x);
return(R_NilValue);
}
I got the result : x value is: -466460838
Could
2006 Mar 17
1
How to change the label in plot.ts ?
Hi you guys:
I have been wondering if there is any way to change the labeling in plot.ts( ), for example , if I plot two sequences,
i always got y labels as "series1", "series2", I tried to use ylab=c((expression(mu_1)),(expression(mu_2))), but it
doesn't work.
thanks in advance for any help
best.
2006 Oct 28
1
A quesiton on data manipulation
Hi,
I have a data set (data frame) describing some features of the students in a high school in the following format:
Stu ID Year feature 1 feature 2 .............
1001 1990
1001 1991
1001 1992
1002 1990
1002 1991
1002 1992
Some features of a few of these students are missing, I would like to
2007 Jan 04
1
need help with debug package
Hi all,
I met a problem while using the debug package, I have the following program:
mainfun<- function(){
beta<-1
result<-subfun(beta+x)
}
subfun<-function(expr){
y <- eval(expr, envir=list(x=c(1,2)),enclos = parent.frame())
return(y)
}
I have no problem using this program without calling the debug
2007 Dec 27
1
Efficiency of for-loop in R
Hi,
I just realized that in Matlab, as long as memory is pre-allocated, doing for-loop doesn't cost more time than doing things in vector form.
But it seems in R, it still cost a lot to do for-loop. Is there any improvement in R that I missed. Thanks a lot.
Merry Xmas Everyone !
2011 Feb 23
1
[LLVMdev] LLVM ExecutionEngine/JIT trampoline question
I understand that we need to push the address to a register then branch
using the register. But i am asking why there is a trampoline there such
that a call to foo is first branched to an snippet and the snippet branches
to the X86CompilationCallback. is this snippet necessary ?
Thanks
Xin
On Tue, Feb 22, 2011 at 12:39 PM, Reid Kleckner <reid.kleckner at gmail.com>wrote:
> The
2011 Feb 22
0
[LLVMdev] LLVM ExecutionEngine/JIT trampoline question
The address of the callee may be more than 2 GB away in memory, which
cannot be encoded as an immediate offset in the call instruction. So,
the value is first materialized with a mov instruction which can
encode the immediate and then jumped to through a register.
Reid
On Tue, Feb 22, 2011 at 12:03 PM, Xin Tong Utoronto <x.tong at utoronto.ca> wrote:
> I have a question on the LLVM JIT
2006 May 10
1
identify high dimension data point
Hi there,
I am having some trouble with the Identify() function, it looks that the identify() function only works on the plot of 2-dimension data set. In high-dimension case , if I use pairs() + identify() in hope to observe all the components of the data point I selected, I get error message. Is there anyway to get around this ? Plus, I also need it to actually compare all the
2006 Oct 17
2
Question about managing searching path
Hi all,
I'm having sometrouble with managing the seach path, in a function , I need to attach some data set at the begining
and detach them at the end, say, myfunction<- function() { attach(mylist); ............. detach(mylist) } ,
the problem is, since I am still debugging this code, sometimes it got error and ended before reaching the end, thus
the data is left in the
2011 Feb 22
2
[LLVMdev] LLVM ExecutionEngine/JIT trampoline question
I have a question on the LLVM JIT
I did some brief memory reading one day and I found that a call to a
non-library function is resolved by the X86CompilationCallback, but the
X86CompilationCallback is reached through a trampoline. why can not the
generated code jump to the X86CompilationCallback function directly ?
0x2b0a6a4d103b: mov $0x2b0a6a561010,%rax
0x2b0a6a4d1045:
2010 Aug 12
5
how to eliminate an element of a list
Hi,
I want to eliminate an element of a list:
list <- seq(1,5,1)
s <- sample(list,1)
lets say s=3
Now I want to remove 3 from the list: list2 = {1,2,4,5}
Can someone give me a tip?
Thanks,
André
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2011 Jun 24
0
[LLVMdev] LLVM autovectorization support
On 24 June 2011 21:13, Xin Tong Utoronto <x.tong at utoronto.ca> wrote:
> I would like to know the status of the autovectorization support in LLVM.
> does LLVM have a loop dependence analysis, does LLVM have a infrastructure
> for autovectorization ? etc.
Not yet, but it's getting there...
http://polly.grosser.es/
cheers,
--renato