473 reputation
313
bio website cs.wisc.edu/~tdw
location University of Wisconsin-Madison
age 27
visits member for 2 years, 5 months
seen Aug 25 at 0:45

Ph.D. student in theoretical computer science interested in the complexity of counting problems.


Aug
6
comment Use of Strassen's algorithm
I am looking for a definitive answer...not "I believe" or "typically used for $N \ge 100$". Someone familiar with the BLAS source code should be able to tell us a specific scenario, which preferably is based solely on a threshold of the matrices' dimensions, when DGEMMS* is called.
Aug
6
comment Use of Strassen's algorithm
@Charles That is good to know, but my original question remains. For what dimension matrices does BLAS use DGEMMS*? On page 108 of Numerical Recipes: The Art of Scientific Computing (3rd ed.), which was published in 2007, it says that BLAS uses Strassen's algorithm when the size of the matries is about 100. Daniel's answer (which he qualifies with "I believe") is in contradiction with this quote.
Aug
3
comment Use of Strassen's algorithm
Paraphrase quote: "For numerical linear algebra, Mathematica uses BLAS and I don't think BLAS uses Strassen's algorithm." Who/where should I ask to confirm this?
Aug
2
awarded  Curious
Aug
1
asked Use of Strassen's algorithm
Apr
6
awarded  Popular Question
Mar
15
awarded  Yearling
Jan
28
accepted Behavior of Reduce with variables as domain
Jan
28
revised Behavior of Reduce with variables as domain
added undocumented tag
Jan
28
asked Behavior of Reduce with variables as domain
Dec
11
awarded  Popular Question
Nov
27
comment How to implement Kemeny-Young method? (rank aggregation problem)
@aeiklmkv Are you saying that you don't know how to program in Mathematica? If so, why are you trying to solve this problem in Mathematica? What is your best programming language?
Nov
12
accepted Best way to compute row eigenvectors
Nov
12
asked Best way to compute row eigenvectors
Mar
15
awarded  Yearling
Sep
10
awarded  Caucus
Aug
1
comment How does RootOfUnityQ work?
Ok, suppose that this is the definition of RootOfUnityQ. The purpose of my question was to be able to verify Mathematica's answer for myself. So my question now becoems this: how does Mathematica compute ArcTan[Sqrt[1/2 (1+Sqrt[5])]]/\[Pi]\[Element]Rationals?
Aug
1
comment How does RootOfUnityQ work?
@R.M I am not looking for (numerically) approximate answers. I want to know with certainty.
Aug
1
awarded  Commentator
Aug
1
comment How does RootOfUnityQ work?
It does not mimic the behavior. I updated the question to discuss your answer.