BCSSTM02: BCS Structural Engineering Matrices (eigenvalue matrices)
Oil rig -- statically condensed

from set BCSSTRUC1, from the Harwell-Boeing Collection

From generalized eigenvalue problem Kx=(lambda)Mx. This is matrix M; matrix K is BCSSTK02 from BCSSTRUC1 set.
Result of applying static condensation to the oil rig model represented by BCSSTK04 and BCSSTM04. Static condensation can be applied in cases where the mass matrix is singular to reduce the problem order while preserving the spectrum. However, the reduced stiffness matrix is usually dense, which is the case here. Good sparse eigenvalue codes should be able to solve a large sparse problem much more quickly than a dense code can solve the reduced problem of order one-half or one-third the original. This problem is probably too small to demonstrate that effect.

Download as

Compressed MatrixMarket format file: bcsstm02.mtx.gz (444 bytes)
Compressed Harwell-Boeing format file: bcsstm02.rsa.gz (479 bytes)

Visualizations

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

Structure Plot	City Plot
	3D Interactive City Plot
	[ VRML Version 2, gzipped ] 8744 bytes

Matrix Statistics

Size	Type
66 x 66, 66 entries	real symmetric positive definite
Nonzeros
total diagonal below diagonal above diagonal A-A' 66 66 0 0 0
Column Data	Row Data
Average nonzeros per column : 1 Standard deviation : 0 index nonzeros longest 1 1 shortest 1 1	Average nonzeros per row : 1 Standard deviation : 0 index nonzeros longest 1 1 shortest 1 1
Bandwidths	Profile Storage
lower 1 upper 1 average |i-j| 0 std.dev. 0	min max ave. std.dev. lower bandwidth 1 1 1 0 upper bandwidth 1 1 1 0 Symmetric skyline storage requirement:66
Heaviest diagonals
offset from main 0 nonzeros 66 accumulated percent 100.00 Top 1 out of 1 nonvoid diagonals.
Conditioning
Frobenius norm 0.82 condition number (est.) 8.8 2-norm (est.) 0.17 diagonal dominance yes

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Last change in this page: Wed Sep 22 13:33:24 US/Eastern 2004 [Comments: ]