Displaying 20 results from an estimated 5000 matches similar to: "Timings of function execution in R [was Re: R in Industry]"
2010 Dec 15
3
Applying function to a TABLE and also "apply, tapply, sapply etc"
Dear R-help forum members,
Suppose I have a data-frame having two variables and single data for each of them, as described below.
variable_1 variable_2
10 20
I have written a function, say, 'fun' which uses input 10 and 20 and gives me desired result.
fun = function(X, Y)
{
X + Y #( I am just giving an example of
2006 Nov 10
1
lattice: histogram of factor variable
Dear all,
I am encountering a problem with lattice in the current version 0.14-13
with R version 2.4.0 on a Windows XP system.
For example,
histogram(~voice.part, singer)
is not labeling the x labels according to the factor levels of
voice.part, which it should do (and has done in former versions of
lattice, as far as I remember).
In addition, I get the warnings
Warning messages:
1:
2007 Apr 12
3
Method dispatch for print() in package its
Dear all,
in the package its the print() method does not seem to correctly work in all circumstances:
> selectMethod(print, "its")
Method Definition:
function (x, ...)
{
print(x@.Data <mailto:x@.Data> , ...)
}
<environment: namespace:its>
Signatures:
x
target "its"
defined "its"
> fundPME.lst[[1]]$irr
An object of
2006 Nov 23
1
Problem with as.ts(zoo-object)
Dear all,
I have an error message, when I try to convert a zoo object (called
test) to ts (on R 2.4.0, Package zoo version 1.2-1, Windows XP)
> test
1994-05-10 1994-06-09 1994-07-09
0.0024943889 0.0024881824 0.0006955831
> str(test)
atomic [1:3] 0.002494 0.002488 0.000696
- attr(*, "index")=Class 'Date' num [1:3] 8895 8925 8955
> is.regular(test)
[1] TRUE
2007 Aug 03
2
Problem with making dll under Windows
Dear all,
I have problems to compile a DLL for Windows XP with R version 2.5.1 (2007-06-27).
See output below:
C:\AZ_DATEN\C, C++\BE_speedup>R CMD SHLIB dmypow.c
Goto undefined subroutine &DynaLoader::bootstrap_inherit at C:\Programme\R\R-2.5
.1\share\perl/XSLoader.pm line 80.
Compilation failed in require at c:/Programme/Perl/lib/IO/Handle.pm line 262.
BEGIN failed--compilation aborted
2006 Nov 14
3
Error in str(its-object)
Dear all,
on my Windows XP R 2.4.0 version with Package its version 1.1.4 I have a problem with
str() applied on an its-object after a simple matrix manipulation on the its object (see below).
I am not sure, whether this a problem with my application, its or str().
Of course, one can make
> str(core(its(mat)) / 1)
num [1:2, 1:3] 1 2 3 4 5 6
- attr(*, "dimnames")=List of 2
..$
2010 Jun 29
1
Performance enhancement for ave
library(plyr)
n<-100000
grp1<-sample(1:750, n, replace=T)
grp2<-sample(1:750, n, replace=T)
d<-data.frame(x=rnorm(n), y=rnorm(n), grp1=grp1, grp2=grp2)
system.time({
d$avx1 <- ave(d$x, list(d$grp1, d$grp2))
d$avy1 <- ave(d$y, list(d$grp1, d$grp2))
})
# user system elapsed
# 39.300 0.279 40.809
system.time({
d$avx2 <- ave(d$x, interaction(d$grp1, d$grp2, drop =
2007 Apr 19
2
rbind() of factors in data.frame
Dear all,
I would like to inquire, if it is a desired feature that the combination with rbind() of two data frames with factors columns does not sort the factors levels of the combined data frame.
> str(rbind(data.frame(a = factor(c(4, 3))), data.frame(a = factor(c(2, 1)))))
'data.frame': 4 obs. of 1 variable:
$ a: Factor w/ 4 levels
2007 Feb 06
15
R in Industry
The other day, CNN had a story on working at Google. Out of curiosity, I
went to the Google employment web site (I'm not looking, but just
curious). In perusing their job posts for statisticians, preference is
given to those who use R and python. Other languages, S-Plus and
something called SAS were listed as lower priorities.
When I started using Python, I noted they have a portion of the
2004 Jul 03
4
counting the occurrences of vectors
Hi:
I have two matrices, A and B, where A is n x k, and B is m x k, where n >> m >> k. Is there a computationally fast way to count the number of times each row (a k-vector) of B occurs in A? Thanks for any suggestions.
Best,
Ravi.
[[alternative HTML version deleted]]
2010 Feb 12
1
paired wilcox test on each row of a large dataframe
hI
I have to calculate V statistic for each row of a large dataframe (28000). I
can not use multtest package for paired wilcox test. I have been using for
loop which are. Is there a way to speed the computation with another method
like using apply or tapply?
My data set looks like this:
11573_MB 11911_MB 11966_MB 12091_MB 12168_MB
12420_MB................
cg00000292
2012 Aug 04
3
Head or Tails game
Hi,
Reading about a "Heads and Tails" game in
http://www.dartmouth.edu/~chance/teaching_aids/books_articles/probability_book/amsbook.mac.pdf
Introduction to Probability (Example 1.4, pp. 5-8).
You toss a coin 40 times. If heads, Peter wins $1, tails, he loses $1. I
think I can do that ok with:
winnings <- sum(sample(c(-1,1), 40, replace=TRUE))
But I have to do it 10,000 times
2007 Oct 08
2
Incompatible methods ("-.POSIXt", "Ops.difftime") for "-"
Dear all,
according to the Help-page of DateTimeClasses {base} I should be able to do
time - z
with
time date-time objects
z a numeric vector (in seconds) or an object of class "difftime".
However, on R version 2.6.0 (Windows XP) I get
> Sys.time() - as.difftime(c("0:3:20", "11:23:15"))
Time differences in mins
[1] 1191837998 1191837318
2004 Jul 01
3
list structure question
Hi,
I have a list in which element is a vector (all of the same length and
all numeric). I want to find the mean of the first elements of the
vectors, the mean of the second elements of the vectors and so on.
Currently I convert the list to a data.frame and apply rowMeans(). But
is there a way to to do this directly on the list? I seem to recall a
post in which there was such a function (or
2008 Aug 27
5
Integrate a 1-variable function with 1 parameter (Jose L. Romero)
Hey fellas:
I would like to integrate the following function:
integrand <- function (x,t) {
exp(-2*t)*(2*t)^x/(10*factorial(x))
}
with respect to the t variable, from 0 to 10.
The variable x here works as a parameter: I would like to integrate the said function for each value of x in 0,1,..,44.
I have tried Vectorize to no avail.
Thanks in advance,
jose romero
2007 Oct 05
8
Linux editor for R+LaTeX, but not Emacs
Using Tinn-R (in windows) is possible to run latex and R from the same
editor, which was great. Now, I am using Ubuntu-linux, which has been
better than WinXP. Currently, I am using Emacs (and then install ESS)
for running LaTeX and R from a same editor-program (like i was doing
with Tinn-R in windows). Nevertheless, and even though i have been using
Emacs for almost 2 years, it is not as
2004 Dec 16
8
counting numbers without replicates in a vector
Hi,
I am just wondering if there is an easy way to count
in a numeric vector how many numbers don't have
replicates.
For example,
a=c(1,1,2,2,3,4,5), how can I know there are three
numbers (3, 4 and 5) without replicates?
Thank you!
Jun
=====
2009 Dec 08
4
lower.tail option in pnorm
Hi,
I would have thought that these two constructions would
produce the same result but they do not.
Resp <- rbinom(10, 1, 0.5)
Stim <- rep(0:1, 5)
mm <- model.matrix(~ Stim)
Xb <- mm %*% c(0, 1)
ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb)))
pnorm(as.vector(Xb), lower.tail = Resp, log.p = TRUE)
> ifelse(Resp, log(pnorm(Xb)), log(1 - pnorm(Xb)))
[1] -0.6931472 -1.8410216
2011 Sep 02
5
Hessian Matrix Issue
Dear All,
I am running a simulation to obtain coverage probability of Wald type
confidence intervals for my parameter d in a function of two parameters
(mu,d).
I am optimizing it using "optim" method "L-BFGS-B" to obtain MLE. As, I
want to invert the Hessian matrix to get Standard errors of the two
parameter estimates. However, my Hessian matrix at times becomes
2009 Nov 02
2
a prolem with constrOptim
Hi,
I apologize for the long message but the problem I encountered can't be stated in a few lines.
I am having some problems with the function constrOptim. My goal is to maximize the likelihood of product of K multinomials, each with four catagories under linear constraints on the parameter values. I have found that the function does not work for many data configurations.
#The likelihood