• SJSU Singular Matrix Database
• Matrix group: Pothen
• Click here for a description of the Pothen group.
• Click here for a list of all matrices
• Click here for a list of all matrix groups

• Matrix: Pothen/sphere3
• Description: sphere3, with coordinates. From NASA, collected by Alex Pothen
• download as a MATLAB mat-file, file size: 5 KB. Use SJget(219) or SJget('Pothen/sphere3') in MATLAB.
• download in Matrix Market format, file size: 4 KB.
• download in Rutherford/Boeing format, file size: 3 KB.

Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.

 Matrix properties (click for a legend) number of rows 258 number of columns 258 structural full rank? yes structural rank 258 numerical rank 253 dimension of the numerical null space 5 numerical rank / min(size(A)) 0.98062 Euclidean norm of A 6.9725 calculated singular value # 253 0.047572 numerical rank defined using a tolerance max(size(A))*eps(norm(A)) = 2.2915e-013 calculated singular value # 254 4.6123e-016 gap in the singular values at the numerical rank: singular value # 253 / singular value # 254 1.0314e+014 calculated condition number 7.417e+016 condest 1.3639e+018 nonzeros 1,794 # of blocks from dmperm 1 # strongly connected comp. 1 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 NASA editor G. Kumfert, A. Pothen date 2003 kind structural problem 2D/3D problem? yes SJid 219 UFid 884

 Additional fields size and type coord full 258-by-3

 Ordering statistics: AMD METIS nnz(chol(P*(A+A'+s*I)*P')) 4,467 4,201 Cholesky flop count 1.1e+005 9.1e+004 nnz(L+U), no partial pivoting 8,676 8,144 nnz(V) for QR, upper bound nnz(L) for LU 5,191 5,768 nnz(R) for QR, upper bound nnz(U) for LU 9,301 10,052

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.