Rajat/Raj1
Circuit simulation matrix from Raj
Name 
Raj1 
Group 
Rajat 
Matrix ID 
1863 
Num Rows

263,743 
Num Cols

263,743 
Nonzeros

1,300,261 
Pattern Entries

1,302,464 
Kind

Circuit Simulation Problem 
Symmetric

No 
Date

2007 
Author

Raj 
Editor

T. Davis 
Structural Rank 
263,743 
Structural Rank Full 
true 
Num Dmperm Blocks

169 
Strongly Connect Components

3 
Num Explicit Zeros

2,203 
Pattern Symmetry

99.9% 
Numeric Symmetry

57.6% 
Cholesky Candidate

no 
Positive Definite

no 
Type

real 
Download 
MATLAB
Rutherford Boeing
Matrix Market

Notes 
High fillin with KLU, because the matrix is nearly singular and lots of
partial pivoting occurs. If the pattern of A+A' is considered to be the
nonzero pattern of a symmetric positive definite matrix, then nnz(L) has
only 3,728,967 nonzeros using p=amd(A) and chol(A(p,p)), where A excludes
the explicit zeros in Problem.Zeros. The flop count for the Cholesky
factorization is only 340.9 million. With a pivot tolerance of 2.2e16,
KLU Version 1.0 constructs and LU factorization with about 31 million
nonzeros, even though it uses AMD for the diagonal blocks of the BTF for
which the expected nnz(L) is only 3.705 million (for the Cholesky factor
ization of the large diagonal block). The BTF form has little impact on
the factorization.
