Matrix: Muite/Chebyshev3
Description: Integration matrix, Chebyshev method, 4th order semilinear initial BVP
(bipartite graph drawing) | (graph drawing of A+A') |
Matrix properties | |
number of rows | 4,101 |
number of columns | 4,101 |
nonzeros | 36,879 |
structural full rank? | yes |
structural rank | 4,101 |
# of blocks from dmperm | 1 |
# strongly connected comp. | 1 |
explicit zero entries | 0 |
nonzero pattern symmetry | 50% |
numeric value symmetry | 0% |
type | real |
structure | unsymmetric |
Cholesky candidate? | no |
positive definite? | no |
author | B. Muite |
editor | T. Davis |
date | 2007 |
kind | structural problem |
2D/3D problem? | yes |
Notes:
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.
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 28,683 |
Cholesky flop count | 2.0e+05 |
nnz(L+U), no partial pivoting, with AMD | 53,265 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 16,400 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 8,411,151 |
SVD-based statistics: | |
norm(A) | 2.01756e+06 |
min(svd(A)) | 3.33757e-12 |
cond(A) | 6.04502e+17 |
rank(A) | 4,099 |
sprank(A)-rank(A) | 2 |
null space dimension | 2 |
full numerical rank? | no |
singular value gap | 168166 |
singular values (MAT file): | click here |
SVD method used: | s = svd (full (A)) ; |
status: | ok |
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.