JGD_Trefethen/Trefethen_20000b
Diagonal matrices with primes, Nick Trefethen, Oxford Univ.
| Name | Trefethen_20000b | 
| Group | JGD_Trefethen | 
| Matrix ID | 2212 | 
| Num Rows | 19,999 | 
| Num Cols | 19,999 | 
| Nonzeros | 554,435 | 
| Pattern Entries | 554,435 | 
| Kind | Combinatorial Problem | 
| Symmetric | Yes | 
| Date | 2008 | 
| Author | N. Trefethen | 
| Editor | J.-G. Dumas | 
 
 
| Structural Rank | 19,999 | 
| Structural Rank Full | true | 
| Num Dmperm Blocks | 1 | 
| Strongly Connect Components | 1 | 
| Num Explicit Zeros | 0 | 
| Pattern Symmetry | 100% | 
| Numeric Symmetry | 100% | 
| Cholesky Candidate | yes | 
| Positive Definite | yes | 
| Type | integer | 
 
| SVD Statistics | 
| Matrix Norm | 2.247372e+05 | 
| Minimum Singular Value | 2.343285e+00 | 
| Condition Number | 9.590693e+04 | 
| Rank | 19,999 | 
| sprank(A)-rank(A) | 0 | 
| Null Space Dimension | 0 | 
| Full Numerical Rank? | yes | 
| Download Singular Values | MATLAB | 
 
 
| Download | MATLAB
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Matrix Market | 
| Notes | 
Diagonal matrices with primes, Nick Trefethen, Oxford Univ.           
From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,          
http://ljk.imag.fr/membres/Jean-Guillaume.Dumas/simc.html             
                                                                      
Problem 7 of the Hundred-dollar, Hundred-digit Challenge Problems,    
SIAM News, vol 35, no. 1.                                             
                                                                      
7. Let A be the 20,000 x 20,000 matrix whose entries are zero         
everywhere except for the primes 2, 3, 5, 7, . . . , 224737 along the 
main diagonal and the number 1 in all the positions A(i,j) with       
|i-j| = 1,2,4,8, . . . ,16384.  What is the (1,1) entry of inv(A)?    
                                                                      
http://www.siam.org/news/news.php?id=388                              
                                                                      
Filename in JGD collection: Trefethen/trefethen_20000__19999_minor.sms |