BCSSTK26: BCS Structural Engineering Matrices (eigenvalue problems and linear equations)
Seismic analysis, nuclear power station

from set BCSSTRUC4, from the Harwell-Boeing Collection

From generalized eigenvalue problem Kx=(lambda)Mx. This is matrix K; matrix M is BCSSTM26 from BCSSTRUC4 set.
BCSSTK26/BCSSTM26 is from a vibration station. It is of interest because the number of eigenvalues needed for the seismic analysis was quite large - the lowest 197. The large number effectively defeats sparse eigenvalue routines that do not shift, and stands as a real benchmark for shifted algorithms.

Download as

Compressed MatrixMarket format file: bcsstk26.mtx.gz (165343 bytes)
Compressed Harwell-Boeing format file: bcsstk26.rsa.gz (135696 bytes)

Visualizations

Click on image to get an enlarged version. Click on label to get an explanation.

Structure Plot	City Plot

Matrix Statistics

Size	Type
1922 x 1922, 16129 entries	real symmetric indefinite
Nonzeros
total diagonal below diagonal above diagonal A-A' 30336 1922 14207 14207 0
Column Data	Row Data
Average nonzeros per column : 16 Standard deviation : 5.7 index nonzeros longest 1572 33 shortest 224 3	Average nonzeros per row : 16 Standard deviation : 5.7 index nonzeros longest 1572 33 shortest 224 3
Bandwidths	Profile Storage
lower 234 upper 234 average |i-j| 74 std.dev. 75	min max ave. std.dev. lower bandwidth 1 234 1e+02 74 upper bandwidth 1 234 1e+02 74 Symmetric skyline storage requirement:191968
Heaviest diagonals
offset from main 0 -2 2 -1 1 -4 4 -3 3 -5 nonzeros 1922 1233 1233 1155 1155 647 647 592 592 308 accumulated percent 6.34 10.40 14.46 18.27 22.08 24.21 26.34 28.30 30.25 31.26 Top 10 out of 467 nonvoid diagonals.
Conditioning
Frobenius norm 4e+11 condition number (est.) 2.3e+08 2-norm (est.) 1.6e+11 diagonal dominance no

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Last change in this page: Wed Sep 22 13:33:27 US/Eastern 2004 [Comments: ]