• SJSU Singular Matrix Database
• Matrix group: HB

• Matrix: HB/lns_511
• Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE
• download as a MATLAB mat-file, file size: 18 KB. Use SJget(141) or SJget('HB/lns_511') 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 511 number of columns 511 structural full rank? yes structural rank 511 numerical rank 469 dimension of the numerical null space 42 numerical rank / min(size(A)) 0.91781 Euclidean norm of A 4.2055e+010 calculated singular value # 469 0.0041691 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 0.0038986 calculated singular value # 470 0.0035998 gap in the singular values at the numerical rank: singular value # 469 / singular value # 470 1.1582 calculated condition number 3.3293e+015 condest 6.3735e+015 nonzeros 2,796 # of blocks from dmperm 135 # strongly connected comp. 98 entries not in dmperm blocks 425 explicit zero entries 0 nonzero pattern symmetry 80% numeric value symmetry 2% type real structure unsymmetric Cholesky candidate? no positive definite? no

 author I. Jones editor I. Duff, R. Grimes, J. Lewis date 1982 kind computational fluid dynamics problem 2D/3D problem? yes SJid 141 UFid 190

 Ordering statistics: AMD METIS DMPERM+ nnz(chol(P*(A+A'+s*I)*P')) 5,843 6,405 10,439 Cholesky flop count 1.4e+005 1.7e+005 4.8e+005 nnz(L+U), no partial pivoting 11,175 12,299 20,792 nnz(V) for QR, upper bound nnz(L) for LU 9,771 11,089 9,232 nnz(R) for QR, upper bound nnz(U) for LU 20,208 22,612 17,018

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.