Displaying 6 results from an estimated 6 matches for "hereas".
Did you mean:
whereas
2016 Apr 20
6
Solving sparse, singular systems of equations
I have a situation in R where I would like to find any x (if one exists) that solves the linear system of equations Ax = b, where A is square, sparse, and singular, and b is a vector. Here is some code that mimics my issue with a relatively simple A and b, along with three other methods of solving this system that I found online, two of which give me an error and one of which succeeds on the
2016 Apr 20
0
Solving sparse, singular systems of equations
> On 20 Apr 2016, at 13:22, A A via R-help <r-help at r-project.org> wrote:
>
>
>
>
> I have a situation in R where I would like to find any x (if one exists) that solves the linear system of equations Ax = b, where A is square, sparse, and singular, and b is a vector. Here is some code that mimics my issue with a relatively simple A and b, along with three other
2016 Apr 20
0
Solving sparse, singular systems of equations
This is not a solution but your lsfit attempt
#Error in lsfit(A, b) : only 3 cases, but 4 variables
lsfit(A,b)
gave that error because lsfit adds a column of 1 to
its first argument unless you use intercept=FALSE.
Then it will give you an answer (but I think it converts
your sparse matrix into a dense one before doing
any linear algebra).
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On
2016 Apr 20
0
Solving sparse, singular systems of equations
This is kind of like asking for a solution to x+1=x+1. Go back to linear algebra and look up Singular Value Decomposition, and decide if you really want to proceed. See also ?svd and package irlba.
--
Sent from my phone. Please excuse my brevity.
On April 20, 2016 4:22:34 AM PDT, A A via R-help <r-help at r-project.org> wrote:
>
>
>
>I have a situation in R where I would like
2016 Apr 20
1
Solving sparse, singular systems of equations
Thanks for the help. Sorry, I am not sure why it looks like that in the mailing list - it looks much more neat on my end (see attached file).
On Wednesday, April 20, 2016 2:01 PM, Berend Hasselman <bhh at xs4all.nl> wrote:
> On 20 Apr 2016, at 13:22, A A via R-help <r-help at r-project.org> wrote:
>
>
>
>
> I have a situation in R where I would like to
2007 May 08
2
statistics/correlation question NOT R question
This is not an R question but if anyone can help me, it's much
appreciated.
Suppose I have a series ( stationary ) y_t and a series x_t ( stationary
)and x_t has variance sigma^2_x and epsilon is normal
(0, sigma^2_epsilon )
and the two series have the relation
y_t = Beta*x_t + epsilon
My question is if there are particular values that sigma^2_x and
sigma^2_epsilon have to take in