Displaying 20 results from an estimated 10000 matches similar to: "using temporary arrays in R"
2007 Dec 18
3
creating a database
useR's,
I am writing a program in which the input can be multidimensional. As of
now, to hold the input, I have created an n by m matrix where n is the
number of observations and m is the number of variables. The data that I
could potentially use can contain well over 20,000 observations.
Can a simple matrix be used for this or would it be better and more
efficient to create an external
2006 Jul 17
1
multiplying multidimensional arrays (was: Re: [R] Manipulation involving arrays)
I am moving this to r-devel.
The problem and solution below posted on r-help could have been
a bit slicker if %*% worked with multidimensional arrays multiplying
them so that if the first arg is a multidimensional array it is mulitplied
along the last dimension (and first dimension for the second arg).
Then one could have written:
Tbar <- tarray %*% t(wt) / rep(wti, each = 9)
which is a bit
2010 Mar 18
2
how to take multiple subsets from a matrix
useR's
I have a matrix from which I want to take multiple subsets from, according
to a particular scheme I will now describe. The matrix below (mat) is 5x5,
and I want to take 9 subsets of it, each of dimension 3x3. The best way to
explain what the result should look like is with the following:
> dat <- c(3,6,1,9,12,9,2,10,6,5,3,13,1,4,8,9,4,6,10,11,2,7,3,5,10)
> miss <-
2006 Oct 19
2
arraytake for extracting subarrays from multidimensional arrays
Hi,
I recently encountered a problem with array subsetting and came up with a
fix. Given an array of arbitrary dimensions, in which the number of
dimensions is only known at runtime, I wanted to extract a subarray. The
main issue with doing this is that in order to extract a subarray from an
array of (say) 4 dimensions you usually specify something like this
a.subarray <- a[,c(4,2),1:5,]
2012 May 14
3
How to apply a function to a multidimensional array based on its indices
Hello. I have a 4 dimensional array and I want to fill in the slots with
values which are a function of the inputs. Through searching the forums here
I found that the function "outer" is helpful for 2x2 matrices but cannot be
applied to general multidimensional arrays. Is there anything which can
achieve, more efficiently than the following code, the job I want?
K <-
2008 Dec 23
1
Ordered Multidimensional Arrays
Hi,
I am inquiring as to what are the best practices with respect to storing and
manipulating ordered multi-dimensional arrays. For example, suppose I have
a sequence of time-varying covariance matrices of asset returns. The data
is ordered, but the ordering is not necessarily regular (e.g. daily data
omitting weekends and holidays, etc.). The data array is say, N x N x T.
For example, the
2011 Oct 21
2
Converting data frame into multidimensional array
Consider the following data frame
X <- data.frame(Titanic)
Does anyone know of an easy way to convert X into a multidimensional
array? Example that doesn't work
X <- as.array(X, dim=c(4,2,2,2))
To do what I need, X needs to be converted into an array of dimensions
c(4,2,2,2) in this case, not a table.
Thanks in advance.
2002 Apr 19
4
Multidimensional scaling
A student of mine wants to use R to do some nonmetric multidimensional
scaling. According to the R FAQ, there's a package called pcurve that
computes multidimensional scaling solutions, but I was not able to locate
it the contrib page (I am a Windows user with R version 1.4.1). Can
anyone tell me whether it is possible to do nonmetric multidimensional
scaling with R, and if so, how?
John
2019 Jul 25
0
[RFC] A new multidimensional array indexing intrinsic
It's also very common in Fortran.
-David
Michael Ferguson via llvm-dev <llvm-dev at lists.llvm.org> writes:
>> It seems that the main advantage of your proposal is that it would
>> allow for non-constant strides (i.e. variable length arrays) in
>> dimensions other than the first one. Do these appear frequently
>> enough in the programs
2008 Nov 19
2
Multidimensional array with R
Hi there
I know, I'm sure you discussed this stuff 100 times, but I really have
a basic understanding problem, if and how do I create a
multidimensional array in R. I'm coming from MATLAB and there it's as
easy as you ever could imagine.
Ok, so, I want to have an array, where I can fill in data from a Excel
spreadsheet. The array should be addressed like this:
2011 Jan 20
2
Using a list as multidimensional indexer
Hello list.
Another 'puzzle' for which I don't have a clean solution.
Say I have a multidimensional object, e.g.:
Mm<-matrix(1:6, nrow=2, dimnames=list(c("a","b"), c("g","h","i")))
And on the other hand I have a list
Ind<-list("b","g")
This holds, for each dimension, an indexer for that dimension.
Now I would
2019 Jul 22
2
[RFC] A new multidimensional array indexing intrinsic
> It seems that the main advantage of your proposal is that it would allow for non-constant strides (i.e. variable length arrays) in dimensions other than the first one. Do these appear frequently enough in the programs that you're interested in to be worth optimizing for?
Yes - at least in Chapel (which is one of the motivating languages)
these are very common.
In other words, typical
2019 Aug 02
2
[RFC] A new multidimensional array indexing intrinsic
On Aug 2, 2019, at 8:57 AM, Michael Kruse <llvmdev at meinersbur.de> wrote:
>> This is why I ask whether its makes sense to add this to LLVM IR: If you want HPC style loop transformations, I don’t think that LLVM IR itself will ever be great, even with this. This might make some narrow set of cases slightly better, but this is far from a solution, and isn’t contiguous with getting to
2019 Jul 22
2
[RFC] A new multidimensional array indexing intrinsic
We could also simply extend the existing inrange mechanism to
non-constantexpr GEPs. It would remove an inconsistency in the
semantics, be relatively straight forward, and solve the motivating
example.
(I didn't read the proposal in full, so there may be other examples it
doesn't solve.)
Philip
On 7/22/19 10:01 AM, Peter Collingbourne via llvm-dev wrote:
> The restrictions of
2005 Nov 03
1
multidimensional integration not over a multidimensionalrectangle
Hi,
anyone knows about any functions in R can get multidimensional integration
not over a multidimensional rectangle (not adapt).
For example, I tried the following function f(x,n)=x^n/n!
phi.fun<-function(x,n)
{ if (n==1) {
x
}else{
integrate(phi.fun, lower=0, upper=x, n=n-1)$value
}
}
I could get f(4,2)=4^2/2!=8, but failed in f(4,3)=4^3/3! Thanks
Best,
Lynette
2018 Sep 19
2
Regarding Dependence distance dump
On Wed, Sep 19, 2018 at 4:58 AM Venkataramanan Kumar <
venkataramanan.kumar.llvm at gmail.com> wrote:
> Hi,
>
> I tired to see when this behavior changed in LLVM.
> It seems to start from.
> --snip--
> commit 95e5d37d5868ebde2302bc302c1e0af407c5646d
> Author: Sebastian Pop <sebpop at gmail.com>
> Date: Tue Mar 6 21:55:59 2018 +0000
>
> DA: remove
2012 Jun 02
2
Add a dim to an array
Dear list,
I'm trying to add a new dim to a multidimensional array. My array looks
like this
a1 <- array(1:8, c(2, 2, 2))
dimnames(a1) <- list(A = c("A1", "A2"),
B = c("B1", "B2"),
D = c("D1", "D2"))
I would like to add a new dim 'group' with the value "low".
2005 Sep 29
2
solution of convolution equation
Hello,
May be somebody can help me...
I am trying to find a solution of a convolution equation using fft (and
unfortunately I do not have a good background for this).
So I am just trying to figure out how it can be implemented in R. I have
two multidimensional independent variables X and Z
and I know their densities fx and fz, which are multidimensional arrays.
So I have to find the density of
2010 Oct 01
2
How to apply vector value function to a multidimensional array indexed by the remaining dimensions?
Hi,
I am looking for some generalization of colSums and rowSums for general
vector valued functions, and for arrays of more than 2 dimensions.
So as a concrete example, suppose I have a 3 dimensional array, given by x
= array(1:100,c(3,4,5)).
and I want to sum the 3rd index of x to obain a 3 by 4 matrix. Using rowSums
would return a vector of length 3 because it treats the last two indices as
2011 Jan 19
1
combining matrices from a list into a multidimensional array
I get some results back from running an iterative analysis in the form of a list of matrices. What I would like to do with this list is combine it such that all the similar components get combined into a multidimensional array. If possible I'd like to put results[[1]]$resultmean and results[[2]]$resultmean into a 3x3x2 array, and also put results[[1]]$resultsd and results[[2]]$resultsd in a