Displaying 20 results from an estimated 1000 matches similar to: "Efficiency of factor objects"
2009 May 06
4
tapply changing order of factor levels?
Hi,
Does tapply change the order when applied on a factor? Below is the code I
tried.
> mylevels<-c("IN0020020155","IN0019800021","IN0020020064")
>
2003 Oct 02
3
indexing a vector
Dear All:
I'd like to know how to sort and then index a vector of floats by several
levels in R.
For example
>x<-rnorm(100)
> MyLevels<-quantile(x,probs=c(0,.5,1))
> MyLevels
0% 50% 100%
-2.11978442 -0.03770613 2.00186397
next i want to replace each x[i] in x by 1,2,3 or 4 depending on which
quantile that x[i] falls. How do I do that in a
2006 Apr 29
1
splitting and saving a large dataframe
Hi,
I searched for this in the mailing list, but found no results.
I have a large dataframe ( dim(mydata)= 1297059 16, object.size(mydata=
145280576) ) , and I want to perform some calculations which can be done by
a factor's levels, say, mydata$myfactor. So what I want is to split this
dataframe into nlevels(mydata$myfactor) = 80 levels. But I must do this
efficiently, that is, I
2011 Apr 07
1
Assigning a larger number of levels to a factor that has fewer levels
Hello!
I have larger and a smaller data frame with 1 factor in each - it's
the same factor:
large.frame<-data.frame(myfactor=LETTERS[1:10])
small.frame<-data.frame(myfactor=LETTERS[c(9,7,5,3,1)])
levels(large.frame$myfactor)
levels(small.frame$myfactor)
table(large.frame$myfactor)
table(small.frame$myfactor)
myfactor has 10 levels in large.frame and 5 levels in small.frame. All
5
2012 Mar 28
1
discrepancy between paired t test and glht on lme models
Hi folks,
I am working with repeated measures data and I ran into issues where the
paired t-test results did not match those obtained by employing glht()
contrasts on a lme model. While the lme model itself appears to be fine,
there seems to be some discrepancy with using glht() on the lme model
(unless I am missing something here). I was wondering if someone could
help identify the issue. On
2012 Nov 24
1
Adding a new variable to each element of a list
Hello,
I have a list of data with multiple elements, and each element in the list
has multiple variables in it. Here's an example:
### Make the fake data
dv <- c(1,3,4,2,2,3,2,5,6,3,4,4,3,5,6)
subject <- factor(c("s1","s1","s1","s2","s2","s2","s3","s3","s3",
2010 Jul 05
2
repeated measures with missing data
Dear R help group, I am teaching myself linear mixed models with missing data since I would like to analyze a stats design with these kind of models. The textbook example is for the procedure "proc MIXED" in SAS, but I would like to know if there is an equivalent in R. This example only includes two time-measurements across subjects (a t-test "with missing values"), but I
2012 Jan 18
1
drop rare factors
I have a data frame with some factor columns.
I want to drop the rows with rare factor values
(and remove the factor values from the factors).
E.g., frame$MyFactor takes values
A 1,000 times,
B 2,000 times,
C 30 times and
D 4 times.
I want to remove all rows which assume rare values (<1%), i.e., C and D.
i.e.,
frame <- frame[[! (frame$MyFactor %in% c("A","B"))]]
except
2004 Sep 23
2
How to set up a server compatible with Windows apps ?
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
~ I would like to : set up a server on Linux on which my friends can
connect with msn or netmeeting, suporting at least sound conferance, and
optionally video, but I dont want asterisk server to lock up the sound
card; and then, I want to be able to connect that server with a free
Linux tool; I had a look at http://www.voip-info.org/wiki-Asterisk but
2010 Sep 05
0
cov.unscaled in NLS - how to define cov.scaled to make comparable to SAS proc NLIN output - and theoretically WHY are they different
I am running a 3-parameter nonlinear fit using the default Gauss-Newton
method of nls.
initialValues.L = list(b=4,d=0.04,t=180);
fit.nls.L = nls(
myModel.nlm ,
fData.L,
start = initialValues.L,
control = nls.control(warnOnly = TRUE),
trace=T
);
summary.nls.L = summary(fit.nls.L);
I run the same analysis in SAS proc NLIN.
proc nlin data=apples outest=a;
parms b=4 d=.04 t=180;
model Y =
2008 Feb 03
2
alternative for a broken link
Hi all,
In the http://wiki.centos.org/FAQ/General page, there is this description:
If you need to burn the images with another program (cdrecord on
Linux, Nero on Windows, etc.) here is a good reference for burning ISO
images: http://www.linuxiso.org/viewdoc.php/howtoburn.html
The referenced site does not exist any more. Does anyone know good
alternatives?
Thanks,
Akemi
2016 Jun 28
2
[GSoC 2016] Implementation of the packing transformation
2016-06-27 15:52 GMT+05:00 4lbert C0hen <4lbert.h.c0hen at gmail.com>:
> Dear Roman and all,
>
> Such features would be extremely useful to implement array expansion (scalar
> and array renaming, privatization with new subscript expressions of higher
> dimension) and storage mapping optimization (generalizing array
> contraction). It would be interesting to have these
2011 Mar 30
2
summing values by week - based on daily dates - but with some dates missing
Dear everybody,
I have the following challenge. I have a data set with 2 subgroups,
dates (days), and corresponding values (see example code below).
Within each subgroup: I need to aggregate (sum) the values by week -
for weeks that start on a Monday (for example, 2008-12-29 was a
Monday).
I find it difficult because I have missing dates in my data - so that
sometimes I don't even have the
2009 Mar 03
1
repeated measures anova, sphericity, epsilon, etc
I have 3 questions (below).
Background: I am teaching an introductory statistics course in which we are
covering (among other things) repeated measures anova. This time around
teaching it, we are using R for all of our computations. We are starting by
covering the univariate approach to repeated measures anova.
Doing a basic repeated measures anova (univariate approach) using aov()
seems
2016 Jun 29
0
[GSoC 2016] Implementation of the packing transformation
On 06/28/2016 10:53 AM, Roman Gareev wrote:
> 2016-06-27 15:52 GMT+05:00 4lbert C0hen <4lbert.h.c0hen at gmail.com>:
>> Dear Roman and all,
>>
>> Such features would be extremely useful to implement array expansion (scalar
>> and array renaming, privatization with new subscript expressions of higher
>> dimension) and storage mapping optimization (generalizing
2019 Jul 29
2
Efficient way to identify an instruction
Hi Alberto,
I have not used this myself, but I think you should be able to visit your Instruction ‘users()’. I think the name this function was given is a bit confusing, but this returns an iterator range you can iterate through to find instructions that depend on a given one.
Similarly, you have the function ‘uses()’ that can be used to traverse down the DAG when instructions are still on SSA
2010 Oct 13
5
Poisson Regression
Hello everyone,
I wanted to ask if there is an R-package to fit the following Poisson
regression model
log(\lambda_{ijk}) = \phi_{i} + \alpha_{j} + \beta_{k}
i=1,\cdots,N (subjects)
j=0,1 (two levels)
k=0,1 (two levels)
treating the \phi_{i} as nuinsance parameters.
Thank you very much
--
-Tony
[[alternative HTML version deleted]]
2003 Jun 04
2
convert factor to numeric
Hi R-experts!
Every once in a while I need to convert a factor to a vector of numeric
values. as.numeric(myfactor) of course returns a nice numeric vector of
the indexes of the levels which is usually not what I had in mind:
> v <- c(25, 3.78, 16.5, 37, 109)
> f <- factor(v)
> f
[1] 25 3.78 16.5 37 109
Levels: 3.78 16.5 25 37 109
> as.numeric(f)
[1] 3 1 2 4 5
>
What I
2012 Oct 03
2
[LLVMdev] [RFC] OpenMP Representation in LLVM IR
Hal,
> While I think that it will be relatively easy to have the intrinsics
> serve as code-motion barriers for other code that might be threads
> sensitive (like other external function calls), we would need to think
> through exactly how this would work. The easiest thing would be to make
> the intrinsics have having unmodeled side effects, although we might
> want to do
2009 Mar 03
1
[LLVMdev] One way to support unwind on x86
Hi Bjarke,
Bjarke Walling wrote:
> I see. So you check this value stored in a thread-local variable after
> each call? And you lower invoke to a call and branch with regard to
> this value?
>
Yes, that's correct.
> What are these sophisticated techniques you are talking about? My time
> frame for implementing this is, not unlimited, but fairly long. Less
> than a