• SJSU Singular Matrix Database
• Matrix group: HB

• Matrix: HB/lock3491
• Description: FINITE ELEMENT PROBLEM. LOCKHEED CROSS-CONE PROBLEM
• download as a MATLAB mat-file, file size: 71 KB. Use SJget(147) or SJget('HB/lock3491') in MATLAB.

Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.

 Matrix properties (click for a legend) number of rows 3,491 number of columns 3,491 structural full rank? no structural rank 3,416 numerical rank 603 dimension of the numerical null space 2,888 numerical rank / min(size(A)) 0.17273 Euclidean norm of A 53.979 calculated singular value # 603 0.0024373 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 2.4805e-011 calculated singular value # 604 1.5179e-013 gap in the singular values at the numerical rank: singular value # 603 / singular value # 604 1.6057e+010 calculated condition number Inf condest Inf nonzeros 160,444 # of blocks from dmperm 3 # strongly connected comp. 76 explicit zero entries 0 nonzero pattern symmetry symmetric numeric value symmetry symmetric type binary structure symmetric Cholesky candidate? yes positive definite? no

 author W. Loden editor I. Duff, R. Grimes, J. Lewis date 1980 kind structural problem 2D/3D problem? yes SJid 147 UFid 1,180

 Ordering statistics: AMD METIS nnz(chol(P*(A+A'+s*I)*P')) 226,325 252,098 Cholesky flop count 1.9e+007 2.5e+007 nnz(L+U), no partial pivoting 449,159 500,705 nnz(V) for QR, upper bound nnz(L) for LU 387,799 392,770 nnz(R) for QR, upper bound nnz(U) for LU 725,172 712,229

Maintained by Leslie Foster, last updated 24-Apr-2009.

Entries 5 through 14 in the table of matrix properties and the singular
value plot were created using SJsingular code. The other plots
and statistics are produced using utilities from the SuiteSparse package.
Matrix color plot pictures by cspy, a MATLAB function in the CSparse package.