• SJSU Singular Matrix Database
• Matrix group: GHS_indef

• Matrix: GHS_indef/exdata_1
• Description: MATRIX EXDATA FROM STEVE WRIGHT . MA57 SLOWER THAN MA27
• download as a MATLAB mat-file, file size: 18 MB. Use SJget(518) or SJget('GHS_indef/exdata_1') 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 6,001 number of columns 6,001 structural full rank? yes structural rank 6,001 numerical rank 6,000 dimension of the numerical null space 1 numerical rank / min(size(A)) 0.99983 Euclidean norm of A 3.6957e+008 calculated singular value # 6000 0.00039776 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 0.00035769 calculated singular value # 6001 0.00034861 gap in the singular values at the numerical rank: singular value # 6000 / singular value # 6001 1.141 calculated condition number 1.0601e+012 condest 3.1673e+012 nonzeros 2,269,500 # of blocks from dmperm 1 # strongly connected comp. 1 entries not in dmperm blocks 0 explicit zero entries 1 nonzero pattern symmetry symmetric numeric value symmetry symmetric type real structure symmetric Cholesky candidate? no positive definite? no

 author S. Wright editor N. Gould, Y. Hu, J. Scott date 2004 kind optimization problem 2D/3D problem? no SJid 518 UFid 1,235

 Ordering statistics: AMD METIS nnz(chol(P*(A+A'+s*I)*P')) 1,139,251 1,139,251 Cholesky flop count 1.1e+009 1.1e+009 nnz(L+U), no partial pivoting 2,272,501 2,272,501 nnz(V) for QR, upper bound nnz(L) for LU 1,139,251 1,139,251 nnz(R) for QR, upper bound nnz(U) for LU 5,640,751 7,890,751

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 1 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.