Matrix BCSSTK02

BCSSTK02: BCS Structural Engineering Matrices (eigenvalue matrices)
Oil rig -- statically condensed

from set BCSSTRUC1, from the Harwell-Boeing Collection

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From generalized eigenvalue problem Kx=(lambda)Mx. This is matrix K; matrix M is BCSSTM02 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: bcsstk02.mtx.gz (14066 bytes)

Compressed Harwell-Boeing format file: bcsstk02.rsa.gz (10453 bytes)

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Visualizations

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Structure Plot	City Plot

	3D Interactive City Plot
	[ VRML Version 2, gzipped ] 118970 bytes

Matrix Statistics

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Size Type

66 x 66, 2211 entries real symmetric positive definite

Nonzeros

total diagonal below diagonal above diagonal A-A'
4356 66 2145 2145 0

Column Data Row Data

Average nonzeros per column : 66
Standard deviation : 0
index nonzeros
longest 1 66
shortest 1 66
Average nonzeros per row : 66
Standard deviation : 0
index nonzeros
longest 1 66
shortest 1 66

Bandwidths Profile Storage

lower 66 upper 66
average |i-j| 22 std.dev. 16

min max ave. std.dev.
lower bandwidth 1 66 34 19
upper bandwidth 1 66 34 19
Symmetric skyline storage requirement:2211

Heaviest diagonals

offset from main 0 -1 1 -2 2 -3 3 -4 4 -5
nonzeros 66 65 65 64 64 63 63 62 62 61
accumulated percent 1.52 3.01 4.50 5.97 7.44 8.88 10.33 11.75 13.18 14.58

Top 10 out of 131 nonvoid diagonals.

Conditioning

Frobenius norm 5.3e+04 condition number (est.) 1.3e+04
2-norm (est.) 1.8e+04 diagonal dominance no

Set Information

Set BCSSTRUC1
Source:	John Lewis, Boeing Computer Services, Seattle, Washington, USA
Discipline:	Dynamic analyses in structural engineering
Accession:	Summer 1982

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