Description: Schenk: IBM TJ Watson, Yorktown, nonlinear optimization
|(undirected graph drawing)|
|number of rows||67,458|
|number of columns||67,458|
|structural full rank?||yes|
|# of blocks from dmperm||29|
|# strongly connected comp.||29|
|explicit zero entries||56|
|nonzero pattern symmetry||symmetric|
|numeric value symmetry||symmetric|
|Additional fields||size and type|
Revised Nov 2006; relative eps changes to A, right-hand-side added. Note that this matrix should have been placed in the Schenk_IBMNA/ directory when it was first added in August 2004, but moving it now would disrupt exising users of the collection.
|nnz(chol(P*(A+A'+s*I)*P')) with AMD||2,780,353|
|Cholesky flop count||1.5e+09|
|nnz(L+U), no partial pivoting, with AMD||5,493,248|
|nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD||208,094,871|
|nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD||273,333,941|
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 56 explicit zero entries.
For a description of the statistics displayed above, click here.
Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.