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PLAT362: Platzman's oceanographic models
North Atlantic submodel

from set PLATZ, from the Harwell-Boeing Collection

[Download] [Visualizations] [Matrix Statistics] [Set Information]


A finite-difference model for the shallow wave equations for the Atlantic Ocean. This is a one ocean submodel of PLAT1919. Derived as the (negative) square of a purely imaginary skew-symmetric matrix (PLSK362). Hence, the eigenvalues occur in pairs (except for an isolated singleton at zero). Well-known as a difficult eigenproblem.


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Visualizations

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Matrix Statistics

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Size Type
362 x 362, 3074 entries real symmetric indefinite
Nonzeros
totaldiagonalbelow diagonalabove diagonalA-A'
5786 362 2712 2712 0
Column Data Row Data
Average nonzeros per column : 16
Standard deviation : 3.3

indexnonzeros
longest140 19
shortest84 4

Average nonzeros per row : 16
Standard deviation : 3.3

indexnonzeros
longest140 19
shortest84 4

Bandwidths Profile Storage
lower250 upper250
average |i-j|1e+02 std.dev.91
minmaxave.std.dev.
lower bandwidth1 250 1.3e+02 99
upper bandwidth1 250 1.3e+02 99

Symmetric skyline storage requirement:45623

Heaviest diagonals
offset from main0 -1 1 -9 9 -8 8 -10 10 -121
nonzeros362 309 309 159 159 135 135 118 118 97
accumulated percent 6.2611.6016.9419.6922.4324.7727.1029.1431.1832.86

Top 10 out of 121 nonvoid diagonals.
Conditioning
Frobenius norm5 condition number (est.)7.1e+11
2-norm (est.)0.77 diagonal dominanceno


Set Information

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


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