• SJSU Singular Matrix Database
• Matrix group: HB

• Matrix: HB/bcsstm04
• Description: SYMMETRIC MASS MATRIX, OIL RIG, NOT CONDENSED (SAME MODEL AS BCSSTX02)
• download as a MATLAB mat-file, file size: 1 KB. Use SJget(68) or SJget('HB/bcsstm04') 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 132 number of columns 132 structural full rank? no structural rank 66 numerical rank 66 dimension of the numerical null space 66 numerical rank / min(size(A)) 0.5 Euclidean norm of A 0.17283 calculated singular value # 66 0.019747 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 3.6637e-015 calculated singular value # 67 0 gap in the singular values at the numerical rank: singular value # 66 / singular value # 67 Inf calculated condition number Inf condest Inf nonzeros 66 # of blocks from dmperm 68 # strongly connected comp. 132 explicit zero entries 66 nonzero pattern symmetry symmetric numeric value symmetry symmetric type real structure symmetric Cholesky candidate? yes positive definite? no

 author J. Lewis editor I. Duff, R. Grimes, J. Lewis date 1982 kind structural problem 2D/3D problem? yes SJid 68 UFid 59

 Ordering statistics: AMD METIS nnz(chol(P*(A+A'+s*I)*P')) 132 132 Cholesky flop count 1.3e+002 1.3e+002 nnz(L+U), no partial pivoting 132 132 nnz(V) for QR, upper bound nnz(L) for LU 132 132 nnz(R) for QR, upper bound nnz(U) for LU 132 132

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 66 explicit zero entries.

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.