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PLAT1919: Platzman's oceanographic models
full three ocean model

from set PLATZ, from the Harwell-Boeing Collection

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A finite-difference model for the shallow wave equations for the Atlantic and Indian Oceans. Derived as the (negative) square of a purely imaginary skew-symmetric matrix (PLSK1919). Hence, the eigenvalues occur in pairs (except for an isolated singleton at zero). Well-known as a difficult eigenproblem.

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Structure Plot City Plot
structure plot city plot

Matrix Statistics

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Size Type
1919 x 1919, 17159 entries real symmetric indefinite
totaldiagonalbelow diagonalabove diagonalA-A'
32399 1919 15240 15240 0
Column Data Row Data
Average nonzeros per column : 17
Standard deviation : 2.9

longest682 19
shortest63 3

Average nonzeros per row : 17
Standard deviation : 2.9

longest682 19
shortest63 3

Bandwidths Profile Storage
lower1298 upper1298
average |i-j|5.2e+02
lower bandwidth1 1298 6.5e+02 5.2e+02
upper bandwidth1 1298 6.5e+02 5.2e+02

Symmetric skyline storage requirement:1240723

Heaviest diagonals
offset from main0 -1 1 -36 36 -35 35 -1260 1260 -1259
nonzeros1919 1762 1762 700 700 488 488 404 404 398
accumulated percent 5.9211.3616.8018.9621.1222.6324.1325.3826.6327.86

Top 10 out of 393 nonvoid diagonals.
Frobenius norm22 condition number (est.)1e+02
2-norm (est.)2.9 diagonal dominanceno

Set Information

Source: John Lewis, Boeing Computer Services, Seattle, Washington
Discipline:Oceanic modeling
Accession:Summer 1975

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Last change in this page: Wed Sep 22 13:33:48 US/Eastern 2004 [Comments: ]