Displaying 20 results from an estimated 800 matches similar to: "Matrix library error: "should never happen; please report""
2006 Dec 19
1
preserving sparse matrices (Matrix)
Hi,
I have sparse (tridiagonal) matrices, and I use the Matrix package for
handling them. For certain computations, I need to either set the
first row to zero, or double the last row. I find that neither
operation preserves sparsity, eg
> m <- Diagonal(5)
> m
5 x 5 diagonal matrix of class "ddiMatrix"
[,1] [,2] [,3] [,4] [,5]
[1,] 1 . . . .
[2,] . 1
2009 Oct 24
1
operations on sparse matrices, and dense intermediary steps
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Hi,
I'm doing some basic operations on large sparse matrices, for example
getting a row.
it takes close to 30 seconds on a 3Ghz machine, and shots the memory
usage up to the sky.
I suspect there are dense intermediary steps (which, if true would
defeat the purpose of trying to use sparse representaitons).
As much as I try understanding the
2018 Apr 23
4
R 3.5.0 fails its regression test suite on Linux/x86_64
Hi,
I just tried to upgrade Nixpkgs to R 3.5.0, but unfortunately the new
version fails its regression test suite. We configure the build using
the flags "--without-recommended-packages", in case that's relevant. You
can see a complete build log with all relevant information at [1].
Anyway, the test failures look like this:
| make[3]: Entering directory
2007 Jan 26
2
%*% in Matrix objects
Dear R users,
I need to normalize a bunch of row vectors. At a certain point I need to divide a matrix by a vector of norms. I find that the behavior of Matrix objects differs from normal matrix objects. Example the following code examples differ only in xnormed changing from normal to Matrix object:
x = matrix(1:12,3,4)
x = as(x, "CsparseMatrix")
xnorms = sqrt(colSums(x^2))
2018 Apr 23
0
R 3.5.0 fails its regression test suite on Linux/x86_64
On 23/04/2018 6:33 AM, Peter Simons wrote:
> Hi,
>
> I just tried to upgrade Nixpkgs to R 3.5.0, but unfortunately the new
> version fails its regression test suite. We configure the build using
> the flags "--without-recommended-packages", in case that's relevant. You
> can see a complete build log with all relevant information at [1].
> Anyway, the test
2020 Jul 21
2
trivial typo in ?Matrix::sparse.model.matrix.Rd
>>>>> "AS" == Abby Spurdle
>>>>> on Wed, 22 Jul 2020 00:28:12 +1200 writes:
>> "No documentation for ?sparse.model.matrix? in
>> specified packages and libraries", but it's there after
>> "library(Ecfun)". I find that interesting, because "Matrix" does not
>> appear in the Ecfun
2007 May 15
1
Matrix package: writeMM
Hi,
I'm finding that readMM() cannot read a file written with writeMM().
Example:
library(Matrix)
a = Matrix(c(1,0,3,0,0,5), 10, 10)
a = as(a, "CsparseMatrix")
writeMM(a, "kk.mm")
b = readMM("kk.mm")
Error in validObject(.Object) : invalid class "dgTMatrix" object: all row
indices must be between 0 and nrow-1
Thoughts?
Thanks,
-Jose
--
Jose
2007 Jan 23
3
[fixed] vectorized nested loop: apply a function that takes two rows
(Extremely sorry, disregard previous email as I hit send before pasting the latest version of the example; this one is smaller too)
Dear R users,
I want to apply a function that takes two vectors as input to all pairs
(combinations (nrow(X), 2))of matrix rows in a matrix.
I know that ideally, one should avoid loops in R, but after reading the docs for
do.call, apply, etc, I still don't know
2007 Jan 23
3
[fixed] vectorized nested loop: apply a function that takes two rows
(Extremely sorry, disregard previous email as I hit send before pasting the latest version of the example; this one is smaller too)
Dear R users,
I want to apply a function that takes two vectors as input to all pairs
(combinations (nrow(X), 2))of matrix rows in a matrix.
I know that ideally, one should avoid loops in R, but after reading the docs for
do.call, apply, etc, I still don't know
2008 Dec 06
1
R vs Python performance-wise
Hi,
Has anyone run any R vs Python (numpy) tests?
I'd love to see what the differences performance-wise are, specially
handling large sparse matrices.
Since both rely on external C code, there might not be much of a
difference.
If you know and use both languages, what are the main differences and what
made you stick to one over another?
I also noticed that there are strong libraries
2007 Apr 16
1
colSum() in Matrix objects
Hi,
I'd like to simply add column-wise using Matrix objects (Csparse).
It looks like one can apply mosty any base function to these objects
(i.e., apply, colSums), but there is a nasty conversion to traditional
matrix objects if one does that.
Is there any workaround? I can see colSum listed in the help for Class
'CsparseMatrix' , but I wonder whether I'm using the default
2020 Jul 21
0
trivial typo in ?Matrix::sparse.model.matrix.Rd
On 2020-07-21 09:00, Martin Maechler wrote:
>>>>>> "AS" == Abby Spurdle
>>>>>> on Wed, 22 Jul 2020 00:28:12 +1200 writes:
> >> "No documentation for ?sparse.model.matrix? in
> >> specified packages and libraries", but it's there after
> >> "library(Ecfun)". I find that interesting,
2004 Jun 29
1
PAM clustering: using my own dissimilarity matrix
Hello,
I would like to use my own dissimilarity matrix in a PAM clustering with
method "pam" (cluster package) instead of a dissimilarity matrix created
by daisy.
I read data from a file containing the dissimilarity values using
"read.csv". This creates a matrix (alternatively: an array or vector)
which is not accepted by "pam": A call
2001 Jan 09
2
PAM clustering (using triangular matrix)
Hi,
I'm trying to use a similarity matrix (triangular) as input for pam() or
fanny() clustering algorithms.
The problem is that this algorithms can only accept a dissimilarity
matrix, normally generated by daisy().
However, daisy only accept 'data matrix or dataframe. Dissimilarities
will be computed between the rows of x'.
Is there any way to say to that your data are already a
2012 Aug 14
2
Communative Matrix Multiplcation
Friends
I'm not seeing why the following occurs:
> T1 <- (A1 - A2) %*% D
> T2 <- (A1 %*% D) - (A2 %*% D)
> identical(T1, T2)
[1] FALSE
Harold
> dput(A1)
new("dsCMatrix"
, i = c(0L, 1L, 2L, 3L, 0L, 1L, 4L, 2L, 3L, 5L)
, p = c(0L, 1L, 2L, 3L, 4L, 7L, 10L)
, Dim = c(6L, 6L)
, Dimnames = list(NULL, NULL)
, x = c(5, 5, 5, 5, 5, 5, 10, 5, 5, 10)
2019 Mar 22
2
selectMethod() can fail to find methods in situations of multiple dispatch
Fine with me as long as eliminating the inconveniences associated with it can be put on the roadmap. The alias instability and the fact that the user has no way to know if s/he should do ?`foo,numeric-method` or ?`foo,numeric,ANY-method` to find the method has been a long-standing problem.
H.
On 3/21/19 21:29, Michael Lawrence wrote:
If we started over, I'd try to avoid this sort of
2016 Apr 20
0
Matrix: How create a _row-oriented_ sparse Matrix (=dgRMatrix)?
>>>>> Henrik Bengtsson <henrik.bengtsson at gmail.com>
>>>>> on Tue, 19 Apr 2016 14:04:11 -0700 writes:
> Using the Matrix package, how can I create a row-oriented sparse
> Matrix from scratch populated with some data? By default a
> column-oriented one is created and I'm aware of the note that the
> package is optimized for
2020 Jul 21
3
trivial typo in ?Matrix::sparse.model.matrix.Rd
Hi, Martin, Ben, et al.:
On 2020-07-21 04:33, Martin Maechler wrote:
>>>>>> Ben Bolker
>>>>>> on Mon, 20 Jul 2020 20:11:04 -0400 writes:
>> ? "form" -> "from". Diff against latest SVN:
>> Index: sparse.model.matrix.Rd
>> ===================================================================
>> ---
2017 Oct 21
1
What exactly is an dgCMatrix-class. There are so many attributes.
> On Oct 21, 2017, at 7:50 AM, Martin Maechler <maechler at stat.math.ethz.ch> wrote:
>
>>>>>> C W <tmrsg11 at gmail.com>
>>>>>> on Fri, 20 Oct 2017 15:51:16 -0400 writes:
>
>> Thank you for your responses. I guess I don't feel
>> alone. I don't find the documentation go into any detail.
>
>> I also find
2006 Apr 27
3
gmane?
Hi All,
I recently found gmane
http://gmane.org/
It's a system to covert mail to news and back, with the nice property of
keeping
a searchable archive... Very convenient if you are subscribed to many lists
and
don't want to have your mail box cluttered. I use it to read several mailing
lists already, but R is not available there.
I wonder if the admins know about gmane and if they