Description: Integration matrix, Chebyshev method, 4th order semilinear initial BVP
|(bipartite graph drawing)||(graph drawing of A+A')|
|number of rows||68,121|
|number of columns||68,121|
|structural full rank?||yes|
|# of blocks from dmperm||1|
|# strongly connected comp.||1|
|explicit zero entries||0|
|nonzero pattern symmetry||30%|
|numeric value symmetry||0%|
Chebyshev integration matrix from Benson Muite, Oxford. Details of the matrices can be found in a preprint at http://www.maths.ox.ac.uk/~muite entitled "A comparison of Chebyshev methods for solving fourth-order semilinear initial boundary value problems," June 2007. These matrices are very ill-conditioned, partly because of the dense rows which are hard to scale when coupled with the rest of the matrix.
|nnz(chol(P*(A+A'+s*I)*P')) with AMD||22,994,095|
|Cholesky flop count||1.6e+10|
|nnz(L+U), no partial pivoting, with AMD||45,920,069|
|nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD||118,684,230|
|nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD||2,320,269,381|
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.