• SJSU Singular Matrix Database
• Matrix group: Andrianov

• Matrix: Andrianov/net25
• Description: net25 matrix from Alexander Andrianov, SAS Institute Inc.
• download as a MATLAB mat-file, file size: 392 KB. Use SJget(420) or SJget('Andrianov/net25') 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 9,520 number of columns 9,520 structural full rank? yes structural rank 9,520 numerical rank 9,058 dimension of the numerical null space 462 numerical rank / min(size(A)) 0.95147 Euclidean norm of A 70.426 calculated singular value # 9058 0.29266 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 1.3529e-010 calculated singular value # 9059 3.0582e-014 gap in the singular values at the numerical rank: singular value # 9058 / singular value # 9059 9.5699e+012 calculated condition number 1.3041e+019 condest Inf nonzeros 401,200 # of blocks from dmperm 2 # strongly connected comp. 2 entries not in dmperm blocks 0 explicit zero entries 0 nonzero pattern symmetry symmetric numeric value symmetry symmetric type binary structure symmetric Cholesky candidate? yes positive definite? no

 author A. Andrianov editor T. Davis date 2006 kind optimization problem 2D/3D problem? no SJid 420 UFid 1,389

 Ordering statistics: AMD METIS DMPERM+ nnz(chol(P*(A+A'+s*I)*P')) 1,500,131 1,625,289 1,500,131 Cholesky flop count 6.5e+008 7.6e+008 6.5e+008 nnz(L+U), no partial pivoting 2,990,742 3,241,058 2,990,742 nnz(V) for QR, upper bound nnz(L) for LU 12,248,007 8,103,288 7,835,422 nnz(R) for QR, upper bound nnz(U) for LU 18,725,968 17,009,581 17,037,382

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.