Displaying 20 results from an estimated 1600 matches similar to: "matrix problem"
2008 Mar 13
3
fast way to compare two matrices of combinations
I have a list (length 750), each element containing a vector of unique
strings (unique gene ids), with length up to ~40 (median 15). I want to
compile a matrix of all possible triplets and their frequency within
gene elements. Using combn and a lot of looping, I am accomplishing this
but it is VERY slow.
I've tried to figure out a way to vectorize this, using "match" and
2008 Dec 16
6
[LLVMdev] Another compiler shootout
FYI. http://leonardo-m.livejournal.com/73732.html
If anyone is motivated, please file bugs for the losing cases. Also,
it might make sense to incorporate the tests into our nightly tester
test suite.
Thanks,
Evan
2010 Jan 02
2
help with for loop
Dear useRs,
I want to write a function that generates all the possible combinations of diff().
Example:
If my vector has length 5, I need the diff() until lag=4 ->
c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3), diff(my.vec, lag=4))
If it has length 4, I need until lag=3 ->
c(diff(my.vec), diff(my.vec, lag=2), diff(my.vec, lag=3))
So, it must be until lag=(length(my.vec)-1).
2008 Dec 24
3
Extract values based on indexes without looping?
Dear R-Helpers:
I am a entry level user of R.
Have the following question. Many thanks in advance.
# value.vec stores values
value.vec <- c('a','b','c')
# which.vec stores the locations/indexs of values in value.vec.
which.vec <- c(3, 2, 2, 1)
# How can I obtain the following vector based on the value.vec and which.vec
mentioned above
# vector.I.want <-
2010 Aug 17
4
replacing values in a vector
Dear helpRs
Does anyone have an elegant way of doing the following:
For a given numeric vector, e.g. vec <- c(3,2,6,4,7)
Create a series of vectors where all but 1 of the values are replaced by
0's, e.g.
vec.a <- c(3,0,0,0,0)
vec.b <- c(0,2,0,0,0)
vec.c <- c(0,0,6,0,0)
vec.d <- c(0,0,0,4,0)
vec.e <- c(0,0,0,0,7)
I have looked at `replace', but can't think of a
2013 May 31
62
cpuidle and un-eoid interrupts at the local apic
Recently our automated testing system has caught a curious assertion
while testing Xen 4.1.5 on a HaswellDT system.
(XEN) Assertion ''(sp == 0) || (peoi[sp-1].vector < vector)'' failed at irq.c:1030
(XEN) ----[ Xen-4.1.5 x86_64 debug=n Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e008:[<ffff82c48016b2b4>] do_IRQ+0x514/0x750
(XEN) RFLAGS: 0000000000010093 CONTEXT:
2006 Apr 14
5
vector-factor operation
I found myself wanting to average a vector [vec] within each level of a
factor [Fac], returning a vector of the same length as vec. After a
while I realised that
lm1 <- lm(vec ~ Fac)
fitted(lm1)
did what I want.
But there must be another way to do this, and it would be good to be
able to apply other functions than mean() in this way.
Cheers, Murray
--
Dr Murray Jorgensen
2012 Mar 18
3
assign a value to an element
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
URL : <https://stat.ethz.ch/pipermail/r-help/attachments/20120318/d68edf35/attachment.pl>
2008 Nov 30
6
Regex: workaround for variable length negative lookbehind
Hi all
I have the following regular expression problem: I want to find
complete elements of a vector that end in a repeated character but
where the repetition doesn't make up the whole word. That is, for the
vector vec:
vec<-c("aaaa", "baaa", "bbaa", "bbba", "baamm", "aa")
I would like to get
"baaa"
"bbaa"
2004 Jan 15
3
Extracting multiple elements from a list
For a long time I've wanted a way to conveniently extract multiple elements
from a list, which [[ doesn't allow. Can anyone suggest an efficient
function to do this? Wouldn't it be a sensible addition to R?
For example,
alist <- list()
alist[[1]] <- list()
alist[[1]]$name <- "first"
alist[[1]]$vec <- 1:4
alist[[2]] <- list()
alist[[2]]$name <-
2019 May 31
2
[patch] add sanity checks to quantile()
The attached patch adds some sanity checks to the "type" argument of
quantile(). Output from the following commands show the change of
behavior with the current patch:
vec <- 1:10
quantile(vec, type = c(1, 2))
quantile(vec, type = 10)
quantile(vec, type = "aaa")
quantile(vec, type = NA_real_)
quantile(vec, type = 4.3)
quantile(vec, type = -1)
Current behavior
2008 Dec 16
0
[LLVMdev] Another compiler shootout
On Tuesday 16 December 2008 01:03:36 Evan Cheng wrote:
> FYI. http://leonardo-m.livejournal.com/73732.html
>
> If anyone is motivated, please file bugs for the losing cases. Also,
> it might make sense to incorporate the tests into our nightly tester
> test suite.
FWIW, I just ported my ray tracer benchmark to C and found that llvm-gcc gives
much worse performance than gcc on x86
2009 Sep 01
2
cbind objects using character vectors
Dear list,
I have a character vector such vec.names<- c("a", "b")
It happens that I have also two R objects called "a" and "b" that I would
like to merge. Is it possible to
do something like cbind(vec.names[1], vec.names[2]) ending up with the same
result as cbind(a,b)
Bellow is a reproducible example of what I need to to:
dat<-
2018 Aug 05
2
MASS::boxcox "object not found"
Hi there,
I wrote a function that wraps MASS::boxcox as:
bc <- function(vec) {
lam <- boxcox(lm(vec ~ 1))
lam <- lam$x[which.max(lam$y)]
(vec^lam - 1)/lam
}
When I invoke it as:
> x <- runif(20)
> bc(x)
Error in eval(predvars, data, env) : object 'vec' not found
I have googled, and rewrote the above function as:
bc <- function(vec) {
dat <<-
2018 Aug 05
2
MASS::boxcox "object not found"
Hi there,
I wrote a function that wraps MASS::boxcox as:
bc <- function(vec) {
lam <- boxcox(lm(vec ~ 1))
lam <- lam$x[which.max(lam$y)]
(vec^lam - 1)/lam
}
When I invoke it as:
> x <- runif(20)
> bc(x)
Error in eval(predvars, data, env) : object 'vec' not found
I have googled, and rewrote the above function as:
bc <- function(vec) {
dat <<-
2004 Nov 04
5
Conversion of strings to expressions
Hello,
I'm not sure how to state my question in a technically accurate manner, so
I'll use a short example to clarify my problem:
Say I have a vector,
vec<-c(1,2,3,2)
I would like to be able to "reference" the vector by using the string
containing the name of the vector - that is, I would like to know of some
function which is able to convert the string "vec"
2011 Sep 26
4
Testing for arguments in a function
I don't understand how this function can subset by i when i is missing....
## My function:
myfun = function(vec, i){
ret = vec[i]
ret
}
## My data:
i = 10
vec = 1:100
## Expected input and behavior:
myfun(vec, i)
## Missing an argument, but error is not caught!
## How is subsetting even possible here???
myfun(vec)
Is there a way to check for missing function arguments, *and*
2005 Nov 21
4
Can't figure out warning message
Hi,
I apologize for the previous posting, where the message was not formatted
properly. Here is a better version:
I have written the following function to check whether a vector has elements
satisfying monotonicity.
is.monotone <- function(vec, increase=T){
ans <- TRUE
vec.nomis <- vec[!is.na(vec)]
if (increase & any(diff(vec.nomis,1) < 0, na.rm=T)) ans <- FALSE
2009 Sep 04
2
help with functions
Hi all,
I have got 2 function (see bellow) which are simplifications of what I need
to do. These functions are precisely the same, except for the last line.
My question is, why doesn't function testA work in the same way as function
testB.
Both functions produce two objects, "a" and "b" that must merged with rbind.
The difference is that in testA, I specify the name
2002 Jul 09
3
Error handling
Hi
I wrote a function implementing an algoritm for simulation of spatial
sampling plans (using geoR).
I'm using a range of parameters to perform several simulation and
sometimes this parameters create function errors wich cause the algoritm
to stop.
How can I avoid this ?
Below there's a small example that I made to study the problem but I was
not able to solve it. I've tried