PLAT1919: Platzman's oceanographic models
full three ocean model

from set PLATZ, from the Harwell-Boeing Collection

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.

Download as

Compressed MatrixMarket format file: plat1919.mtx.gz (201452 bytes)
Compressed Harwell-Boeing format file: plat1919.rsa.gz (202631 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
1919 x 1919, 17159 entries	real symmetric indefinite
Nonzeros
total diagonal below diagonal above diagonal A-A' 32399 1919 15240 15240 0
Column Data	Row Data
Average nonzeros per column : 17 Standard deviation : 2.9 index nonzeros longest 682 19 shortest 63 3	Average nonzeros per row : 17 Standard deviation : 2.9 index nonzeros longest 682 19 shortest 63 3
Bandwidths	Profile Storage
lower 1298 upper 1298 average |i-j| 5.2e+02 std.dev. 4.9e+02	min max ave. std.dev. lower bandwidth 1 1298 6.5e+02 5.2e+02 upper bandwidth 1 1298 6.5e+02 5.2e+02 Symmetric skyline storage requirement:1240723
Heaviest diagonals
offset from main 0 -1 1 -36 36 -35 35 -1260 1260 -1259 nonzeros 1919 1762 1762 700 700 488 488 404 404 398 accumulated percent 5.92 11.36 16.80 18.96 21.12 22.63 24.13 25.38 26.63 27.86 Top 10 out of 393 nonvoid diagonals.
Conditioning
Frobenius norm 22 condition number (est.) 1e+02 2-norm (est.) 2.9 diagonal dominance no

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