Displaying 20 results from an estimated 2000 matches similar to: "det(diag(c(NaN, 1))) should be NaN, not 0"
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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2003 Nov 12
2
bug in det using method="qr" (PR#1244) (PR#4450)
I just detected, that det() is not working on complex matrices any more,
due to the fix to the bug reports noted above. I am not happy with this,
as determinants are perfectly usable on complex matrices.
AFAIUI the bugs resulted from less than optimal behaviour of qr() in
certain cases. IMHO this is due to the unhappy decision to use a default for
parameter tol to decide whether the the
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
2005 Mar 22
2
NaN and linear algebra
On 21/03/2005, at 10:09 PM, David Firth wrote:
> I am sorry that I wasn't clear. All that I meant was that *this*
> problem can result in different behaviour in "ordinary" statistical
> applications. For example, if the objective function in a call to
> optim() involves calling one of these linear algebra routines, the
> result may be NaN (on systems other than Mac
2009 Oct 19
1
overloading base function
Hello,
I am trying to write an R package for doing analysis of speaker
recognition systems. The big thing in this line of research is a
DET-plot (detection Error Trade-off, a ROC plot with qnorm() warped
axes). My approach has been to make a class "det" and also a
function "det()" that will prepare the data into the right class.
Now loading the library doesn't like me
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
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;
2006 Sep 26
2
about the determinant of a symmetric compound matrix
Dear R users,
even if this question is not related to an issue about R, probably some of you will be able to help me.
I have a square matrix of dimension k by k with alpha on the diagonal and beta everywhee else.
This symmetric matrix is called symmetric compound matrix and has the form
a( I + cJ),
where
I is the k by k identity matrix
J is the k by k matrix of all ones
a = alpha - beta
c =
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,]
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
2005 Mar 20
1
Re: [R-SIG-Mac] NaN and linear algebra
No, blas/veclib is tested, so aprt this extreme case you should report
some other more commonly used cases in which something fails on OS X.
This will help us to work it out.
As said, I'll try some tests without using veclib and let you know.
I've fowarded this mail to r-devel, which seems to be the right place,
so for future msg on the subject please use r-devel.
stefano
On
2011 Mar 16
2
Singularity problem
Dear R,
If I have remembered correctly, a square matrix is singular if and only if
its determinant is zero. I am a bit confused by the following code error.
Can someone give me a hint?
> a <- matrix(c(1e20,1e2,1e3,1e3),2)
> det(a)
[1] 1e+23
> solve(a)
Error in solve.default(a) :
system is computationally singular: reciprocal condition number = 1e-17
Thanks in advance!
Feng
--
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
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
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
2008 Sep 21
1
Calculating interval for conditional/unconditional correlation matrix
Hi there,
Could anyone please help me to understand what should be done in order not to get this error message: Error: evaluation nested too deeply: infinite recursion / options(expressions=)?
Here is my code:
determinant<-
function(x){det(matrix(c(1.0,0.2,0.5,0.8,0.2,1.0,0.5,0.6,0.5,0.5,0.5,1.0,x,0.8,0.6,x,1.0),ncol=4,byrow=T))}
matrix<-
2003 Aug 15
2
Oja median
I discovered recently that the phrase "Oja median" produces no hits in
Jonathan Baron's very valuable R search engine. I found this surprising
since I've long regarded this idea as one of the more interesting notions
in the multivariate robustness literature. To begin to remedy this oversight
I wrote a bivariate version and then decided that writing a general p-variate
version
2007 Jun 01
1
Determinant function (PR#9715)
Full_Name: Krzysztof Podgorski
Version: R version 2.4.1 (2006-12-18)
OS: Windows XP
Submission from: (NULL) (130.235.3.79)
The function ''det'' works improperly for a singular matrix and returns a
non-zero value even if ''solve'' reports singularity. The matrix is very simple
as shown below.
A <- diag(rep(c(64,8), c(8,8)))
A[9:16,1] <- 8
A[1,9:16] <- 8
2003 Jun 23
3
FW: S4 classes, creating in C
I am using C code to create an S4 object based on Douglas Bates's example
in his lecture notes on
<http://www.ci.tuwien.ac.at/Conferences/DSC-2003/Tutorials/RExtensions/slide
s.pdf>
http://www.ci.tuwien.ac.at/Conferences/DSC-2003/Tutorials/RExtensions/slides
.pdf
e.g.
SEXP La_DGE_dc(SEXP A)
{
SEXP aa = PROTECT(duplicate(A));
SEXP adims, pivot, val;
int
2015 Mar 25
4
F77_CALL/NAME problem
Dear R-devel,
I am trying to use Fortran DGESV subroutine into C. Here it is the relevant
part of the C file I am currently writing
#include<stdio.h>
#include<R.h>
#include<Rmath.h>
#include<math.h>
void F77_NAME(DGESV)( int*, int*, double*, int*, int*, double*, int*, int*);
void solve( int *p, double *A, double *Ainv)
{
...
F77_CALL(DGESV)(p, p, Ain, p, ipiv,