Displaying 20 results from an estimated 6000 matches similar to: "bug in det using method="qr" (PR#1244) (PR#4450)"
2002 Jan 05
1
possible bug in det using method="qr" (PR#1244)
Full_Name: Armin Roehrl
Version: 1.4.0(2001-12-19)
OS: Linux; Suse 7.3
Submission from: (NULL) (217.84.18.204)
Hello,
On a given matrix det returns different results whether
I use the method "qr" or "eivenvalues".
The matrix:
> m2
[,1] [,2] [,3]
[1,] 9.822616e+09 3.841723e+09 79790.09
[2,] 3.841723e+09 1.502536e+09 31251.82
[3,]
2003 Oct 07
1
(PR#4450)
Hello,
When I use det() and qr() on complex matrices the result is in some cases indeterministic. The documentation speaks of numeric matrices (and not of complex matrices) but det() uses qr() which should handle complex matrices correctly. I've also tried using only qr() with
similar results. det() returns a value that is not the determinant of the complex matrix (in accordance with
2022 Nov 09
1
det(diag(c(NaN, 1))) should be NaN, not 0
Hello,
Currently, determinant(A) calculates the determinant of 'A' by factorizing
A=LU and computing prod(diag(U)) [or the logarithm of the absolute value].
The factorization is done by LAPACK routine DGETRF, which gives a status
code INFO, documented [1] as follows:
*> INFO is INTEGER
*> = 0: successful exit
*> < 0: if INFO = -i, the i-th
2006 Nov 07
4
solve computationally singular
Hi uRsers,
when inverting a 2 by 2 matrix using solve, I encountered a error message:
solve.default(sigma, tol = 1e-07) :
system is computationally singular: reciprocal condition number
= 1.7671e-017
and then I test the determinant of this matrix: 6.341393e-06.
In my program, I have a condition block that whether a matrix is
invertible like this:
if(det(sigma)<1e-7) return NULL;
2010 Apr 13
1
Lapack, determinant, multivariate normal density, solution to linear system, C language
r-devel list,
I have recently written an R package that solves a linear least squares
problem, and computes the multivariate normal density function. The bulk
of the code is written in C, with interfacing code to the BLAS and
Lapack libraries. The motivation here is speed. I ran into a problem
computing the determinant of a symmetric matrix in packed storage.
Apparently, there are no explicit
2007 Nov 16
3
R det
Hi,
Which R function I should use to obtain determinant of a matrix with real(and complex) numbers?
Kalin
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2002 Mar 08
1
Random data with correlation
Hello all.
First of all, I have only been using are a short time and I'm not an
expert in statistics either.
I have the following problem. I'm working with measurements of physical
samples, each measurement has about 4000 variables. I have 33 of those
samples. From those 400 variables I deduced through non-statiscal means
that I needed about 200 of them. I read those into a data.frame
2017 Jun 22
2
Unexpected behaviour of base::qr()$rank
2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>:
> On 22.06.2017 17:11, Bernd Funovits wrote:
>>
>> Hello,
>>
>> I experienced some unexpected behaviour while determining the rank of matrices (sometimes 1x1 matrices):
>> base::qr(matrix(1e-20))$rank returns 1 (incorrect)
>> base::qr(diag(c(1, 1e-20)))$rank returns 2
2000 Mar 14
1
qr.solve (fwd)
Two friend reported me a problem, which I can't solve:
(I run R-1.0.0, Debian Linux)
They hava a function "corr.matrix" (see end of mail), and when they
create a 173x173 matrix with this function
V <- corr.matrix(0.3, n=173)
V1 <- qr.solve(V)
reports:
Error in qr(a, tol = tol) : NA/NaN/Inf in foreign function call (arg 1)
For n < 173, qr.solve returns the correct
2007 Dec 05
1
Calculating large determinants
I apologise for not including a reproducible example with this query but I
hope that I can make things clear without one.
I am fitting some finite mixture models to data. Each mixture component
has p parameters (p=29 in my application) and there are q components to
the mixture. The number of data points is n ~ 1500.
I need to select a good q and I have been considering model selection
methods
2018 Jan 22
2
Inconsistent rank in qr()
Hi,
I have noticed different rank values calculated by qr() depending on
LAPACK parameter. When it is FALSE (default) a true rank is estimated and returned.
Unfortunately, when LAPACK is set to TRUE, the min(nrow(A), ncol(A)) is returned
which is only occasionally a true rank.
Would not it be more consistent to replace the rank in the latter case by something
based on the following pseudo code ?
2004 Apr 15
5
Solving Matrices
On April 15th, Elizabeth wrote:
<snip>
> In execises 39-42, determine if the columns of the matrix span
> R4:
<snip>
>(or x <- matrix(data=c(7, -5, 6, -7, 2, -3, 10, 9, -5,
> 4, -2, 2, 8, -9, 7, 15), nrow=4, ncol=4)
>
>That is the whole of the question <snip>
Have you tried det(x) and/or eigen(x) ?
A zero determinant (within
2011 Jan 16
1
\examples{} in Rd file
[Hope this is the right list where to send...]
An attempt to update package 'mnormt' involves the addition of a
small new function called 'pd.solve'. When I come to the package
checking stage, an error occurs in parsing pd.solve.Rd.
The full transcript of the outcome is copied below (it includes details
on my installation) but the critical point is where the \examples{}
section
2017 Jun 22
1
Unexpected behaviour of base::qr()$rank
2017-06-22 20:31 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>:
>
>
> On 22.06.2017 20:09, I?aki ?car wrote:
>>
>> 2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>:
>>>
>>> On 22.06.2017 17:11, Bernd Funovits wrote:
>>>>
>>>>
>>>> Hello,
>>>>
>>>> I
2011 Mar 07
1
a numeric problem
### An numeric problem in R ########
###I have two matrix one is##########
A <- matrix(c(21.97844, 250.1960, 2752.033, 29675.88, 316318.4, 3349550,
35336827,
24.89267, 261.4211, 2691.009, 27796.02, 288738.7, 3011839,
31498784,
21.80384, 232.3765, 2460.495, 25992.77, 274001.6, 2883756,
30318645,
39.85801, 392.2341, 3971.349, 40814.22, 423126.2,
2013 Feb 05
1
impossible to invert a spam-object, but possible when it's a matrix-object
Dear R-users,
a question concerning sparse matrices in package "spam" (spam_0.29-2).
On one hand I have a spam object (n X n) from which I cannot compute the inverse. On the other hand, if I convert this object in a plain matrix, I can find the inverse without any problem.
Specifically I get the following error message:
Error in chol.spam(a, ...) :
Singularity problem when
2010 Jun 04
1
sem R: singular and Could not compute QR decomposition of Hessian
Can somebody help me with the following issue (SEM in R), please:
When I run the model (includes second order models) in R, it gives me the following:
1) In sem.default(ram = ram, S = S, N = N, param.names = pars, var.names = vars, :
Could not compute QR decomposition of Hessian.
Optimization probably did not converge.
2) I have aliased parameters and NaNS
or sometimes when
2018 Jan 22
3
Inconsistent rank in qr()
Le 22/01/2018 ? 17:40, Keith O'Hara a ?crit?:
> This behavior is noted in the qr documentation, no?
>
> rank - the rank of x as computed by the decomposition(*): always full rank in the LAPACK case.
For a me a "full rank matrix" is a matrix the rank of which is indeed min(nrow(A), ncol(A))
but here the meaning of "always is full rank" is somewhat confusing. Does it
2011 Aug 02
1
Functions for Sum of determinants of ranges of matrix subsets
Dear R-help list,
Pls I have this problem. Suppose I have a matrix of size nxn say, generated as follows
z<-matrix(rnorm(n*n,0,1),nrow=n)
I want to write a function such that for i in 1:n, I will remove the rows and columns
corresponding to i (so, will be left with n-1*n-1 submatrix in each cases). Now I need
the sum of the determinant of each of this submatrices. As an example, if n=3, it
2004 Jul 01
1
QR decomposition and rank of a matrix
In summary.manova the qr decomposition of a NxN
matrix
is calculated and for some cases is giving me
a rank < N.
However, following suggestions of professor Ripley to
calculate the rank of a Matrix
On 7 Jun 2002, Brian Ripley wrote:
> For a more reliable answer, look at the SVD
> (function svd) and look at the
> singular values. For example (from lda.default)
X.s <-