• SJSU Singular Matrix Database
• Matrix group: HB

• Matrix: HB/eris1176
• Description: SYMMETRIC PATTERN OF ERISMAN, SUMMER 1973
• download as a MATLAB mat-file, file size: 17 KB. Use SJget(116) or SJget('HB/eris1176') 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 1,176 number of columns 1,176 structural full rank? yes structural rank 1,176 numerical rank 774 dimension of the numerical null space 402 numerical rank / min(size(A)) 0.65816 Euclidean norm of A 80.074 calculated singular value # 774 0.050045 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 1.6712e-011 calculated singular value # 775 6.8194e-014 gap in the singular values at the numerical rank: singular value # 774 / singular value # 775 7.3386e+011 calculated condition number 1.3492e+068 condest Inf nonzeros 18,552 # of blocks from dmperm 2 # strongly connected comp. 2 entries not in dmperm blocks 3 explicit zero entries 0 nonzero pattern symmetry symmetric numeric value symmetry symmetric type binary structure symmetric Cholesky candidate? yes positive definite? no

 author A. Erisman editor A. Curtis, I. Duff, J. Reid date 1973 kind power network problem 2D/3D problem? no SJid 116 UFid 140

 Ordering statistics: AMD METIS DMPERM+ nnz(chol(P*(A+A'+s*I)*P')) 10,483 11,143 10,481 Cholesky flop count 3.2e+005 3.5e+005 3.2e+005 nnz(L+U), no partial pivoting 19,790 21,110 19,789 nnz(V) for QR, upper bound nnz(L) for LU 11,822 15,029 15,369 nnz(R) for QR, upper bound nnz(U) for LU 27,455 33,295 28,918

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.