• SJSU Singular Matrix Database
• Matrix group: MathWorks

• Matrix: MathWorks/Pd_rhs
• Description: Matrix problem X=A\B with many sparse right-hand-sides
• download as a MATLAB mat-file, file size: 57 KB. Use SJget(305) or SJget('MathWorks/Pd_rhs') 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 8,081 number of columns 12,406 structural full rank? no structural rank 4,368 numerical rank 4,368 dimension of the numerical null space 8,038 numerical rank / min(size(A)) 0.54053 Euclidean norm of A 1.3554e+005 calculated singular value # 4368 0.00040297 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 3.6106e-007 calculated singular value # 4369 1.6703e-011 gap in the singular values at the numerical rank: singular value # 4368 / singular value # 4369 2.4126e+007 calculated condition number Inf condest -2 nonzeros 6,323 # of blocks from dmperm 2,872 # strongly connected comp. 14,549 explicit zero entries 0 nonzero pattern symmetry 0% numeric value symmetry 0% type real structure rectangular Cholesky candidate? no positive definite? no

 author P. Anderson editor T. Davis date 2002 kind counter-example problem 2D/3D problem? no SJid 305 UFid 1,171

 Ordering statistics: AMD METIS nnz(V) for QR, upper bound nnz(L) for LU 9,829 10,114 nnz(R) for QR, upper bound nnz(U) for LU 8,788 8,788

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.