search for: subspaces

Displaying 20 results from an estimated 77 matches for "subspaces".

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2011 Apr 14
2
Krylov subspace computations of matrix exponentials
I use the very nice expm functions available from the expm and Matrix packages. My understanding is that for large sparse matrices the currently best methods available are Krylov subspace methods, but they are as far as I can tell not implemented in either of the packages mentioned, nor in any other R package I have found. Does anybody know if Krylov subspace methods are available from any R
2005 Nov 30
0
Running Continuum/Subspace
As of version 0.9.2 the program continuum has started, and not failed right at the beginning like it did in 0.9.1. Now, due to its anti cheating measures, it goes through many kernel32, ntdll, gdi32, advapi32, and comctl32 calls along with some winex11drv calls. For some reason, when i try to log it to a file, it grows to 2 GB or greater. I haven't waited for it to finish, as i don't
2005 Aug 29
1
lme and ordering of terms
Dear R users, When fitting a lme() object (from the nlme library), is it possible to test interactions *before* main effects? As I understand, R conventionally re-orders all terms such that highest-order interactions come last - but I??d like to know if it??s possible (and sensible) to change this ordering of terms. I??ve tried the terms() command (from aov) but I don??t know if something
2004 Aug 06
2
icecast cvs patch
.... but that could be used maliciously to override other > (important) values in the stats core, like "number of users", etc. So to do > this we'd need to put all the metadata fields into some sub-namespace in the > stats core, which I don't think is currently possible? Subspaces were sort of the point, exactly for this reason. Did I forget to build that in? I'm pretty sure it's doable, or else I was an idiot. Either is possible, of course. In any case, putting ALL metadata into the stats is hte right solution I think, and if that means subspaces, so be it :) jac...
2009 Oct 11
2
Why H1=1? (H's the hat matrix)
Suppose I have the following hat matrix: H=X(X'X)^{-1}X' X is a n by p matrix, where n >= p and X_{i,1} = 1 I'm wondering why H1 = 1. (Here, 1 is column vector, whose each element is the number 1) Thank you!
2010 Feb 08
3
Hypercube in R
Dear all, Does anybody have an idea or suggestion how to construct (plot) 4-dimensional hypercube in R. Thanks in advance for any pointers. Regards, Andrej
2011 Mar 02
2
Vector manipulations
I have a question regarding the most efficient way to select a substring of a vector: I have a vector of value v, and I want to select a subspace of this vector called w such that: w=v[1:n] where sum(w) = x I am interested in what you thing would be the most efficient way to do this - I would like to avoid slowing down my simulations as much as possible. Thank you very much for any help that
2012 Feb 13
3
mgcv: increasing basis dimension
hi Using a ts or tprs basis, I expected gcv to decrease when increasing the basis dimension, as I thought this would minimise gcv over a larger subspace. But gcv increased. Here's an example. thanks for any comments. greg #simulate some data set.seed(0) x1<-runif(500) x2<-rnorm(500) x3<-rpois(500,3) d<-runif(500) linp<--1+x1+0.5*x2+0.3*exp(-2*d)*sin(10*d)*x3
2004 Aug 06
2
icecast cvs patch
> A patch that put _configurable_ extra fields from vorbis comment headers into > the stats core might be a good idea, though. Want to do that? Or perhaps a patch which puts all fields into the stats core. Why be selective? jack. --- >8 ---- List archives: http://www.xiph.org/archives/ icecast project homepage: http://www.icecast.org/ To unsubscribe from this list, send a message to
2004 Aug 06
0
icecast cvs patch
...usly to override other > > (important) values in the stats core, like "number of users", etc. So > to do > > this we'd need to put all the metadata fields into some sub-namespace > in the > > stats core, which I don't think is currently possible? > >Subspaces were sort of the point, exactly for this reason. Did I forget >to build that in? I'm pretty sure it's doable, or else I was an idiot. >Either is possible, of course. > >In any case, putting ALL metadata into the stats is hte right solution I >think, and if that means subspac...
2006 May 30
1
when dimensionality is larger than the number of observations?
Hi, there: Can anyone here kindly point some good reference or links on this topic? Esp. some solutions from BioConductor or R, when dealing with microarray-like, "fat" data? thanks, -- Weiwei Shi, Ph.D "Did you always know?" "No, I did not. But I believed..." ---Matrix III [[alternative HTML version deleted]]
2005 Mar 14
1
r: eviews and r // eigen analysis
hi all i have a question that about the eigen analysis found in R and in eviews. i used the same data set in the two packages and found different answers. which is incorrect? the data is: aa ( a correlation matrix) 1 0.9801 0.9801 0.9801 0.9801 0.9801 1 0.9801 0.9801 0.9801 0.9801 0.9801 1 0.9801 0.9801 0.9801 0.9801 0.9801 1 0.9801 0.9801 0.9801 0.9801 0.9801 1 now > svd(aa) $d [1] 4.9204
2008 Jul 17
2
[LLVMdev] Casting between address spaces and address space semantics
Hi all, I'm currently struggling a bit with some problems regarding address spaces and (implicit) casts. I'll explain some context first and then proceed to the actual question I'd like to have answered. In our target platform, we have a number of distinctly different memory banks. To access these from our C code, we declare a global array for each memory, with the address space
2011 Jan 06
1
Splitting a Vector
...e others colinear with it. Then, using that information to split the vector (explanatory variable) in question, into two new vectors, one should correspond to the fitted values and one the residuals of the (I think you could call it nested) model. One vector therefore should be aligned with the subspacespace defined by the other variables colinear with it, and the other will be residual, and so orthogonal to the subspace of the colinear variables. Then by including these two variables in the origional model - the one that showed the order dependency, you can see how much explanatory power the o...
2004 Jul 02
3
How to get the normal direction to a plane?
Dear All Maybe the following is a stupid question. Assume I have 3 coordinate points (not limited to be in 2D or 3D space) a, b, c. It is known that these 3 points will define a plane. The problem is how to get the normal direction that is orthogonal to this plane. Is there an easy way to calculate it using the values of a, b, and c? Thanks for any point or help on this. Fred
2004 Dec 17
3
How to interpret and modify "plot.svm"?
Dear R people, I am trying to plot the results from running svm in library(e1071). I use plot.svm. After searching through the help archives and FAQ, I still have several questions: 1. In default, crosses indicate support vectors. But why are there two colors of crosses? What do they represent? 2. I want to draw a white-gray colored plot and modify the different colored crosses or circles by
2008 Jul 17
0
[LLVMdev] Casting between address spaces and address space semantics
On Thu, Jul 17, 2008 at 5:08 AM, Matthijs Kooijman <matthijs at stdin.nl> wrote: > Now, we are using a function which reads a value from one of these memories > and does some processing. Since we want to execute this function for multiple > memories, we make it accept a pointer in the generic address space (ie, no > address space attribute): > > void do_stuff(char*
2005 May 31
2
Null space (or kernel) and image of a matrix
Hello! Does anyone now if there exist a function that would compute a "null space" (or "kernel" - "Ker") of a matrix and maybe also one that would compute an "image" ("Im") of a matrix. I tried R-site search and google, However I found notnihg useful! Thanks for any sugestions! I am also not sure what an "image" of a matrix is, so
2011 Nov 14
2
How to compute eigenvectors and eigenvalues?
Hello. Consider the following matrix: mp <- matrix(c(0,1/4,1/4,3/4,0,1/4,1/4,3/4,1/2),3,3,byrow=T) > mp [,1] [,2] [,3] [1,] 0.00 0.25 0.25 [2,] 0.75 0.00 0.25 [3,] 0.25 0.75 0.50 The eigenvectors of the previous matrix are 1, 0.25 and 0.25 and it is not a diagonalizable matrix. When you try to find the eigenvalues and eigenvectors with R, R responses: > eigen(mp) $values [1]
2018 Aug 08
2
vctrs: a type system for the tidyverse
El mi?., 8 ago. 2018 a las 19:23, Gabe Becker (<becker.gabe at gene.com>) escribi?: > > Actually, I sent that too quickly, I should have let it stew a bit more. > I've changed my mind about the resolution argument I Was trying to make. > There is more information, technically speaking, in the factor with empty > levels. I'm still not convinced that its the right