SJSU Singular Matrix Database

Description of Problem.kind in the SJSU Singular Matrix Database

The problem kind in the SJSU Singular Matrix Database is the same as in University of Florida Sparse Matrix Collection, except as of 9/21/2008 we have added one problem kind --"ill-posed problem." This kind describes problems with characteristic features of discrete ill-posed problems (see this link).

The description of the other problem kinds that follows (except for the table of counts below) is from the University of Florida Sparse Matrix Collection.

Problem.kind is a string describing the problem. It is constructed from the following keywords.


These terms can be added to any Problem.kind (except that sequence and subsequent never appear together).

Problems with 2D/3D geometry

Problems that normally do not have 2D/3D geometry

Graph problems

As of September 2008, the following kinds appear in the SJsingular collection (along with the number of Problems with that kind):

# problemskind
15 2D/3D problem
3 subsequent 2D/3D problem
3 acoustics problem
1 bipartite graph
35 chemical process simulation problem
2 chemical process simulation problem sequence
11 circuit simulation problem
2 circuit simulation problem sequence
58 subsequent circuit simulation problem
31 computational fluid dynamics problem
5 counter-example problem
25 directed graph
12 directed multigraph
7 directed weighted graph
14 undirected graph
1 undirected multigraph
3 undirected random graph
5 undirected weighted graph
2 undirected weighted random graph
2 duplicate undirected random graph
31 economic problem
1 duplicate economic problem
7 electromagnetics problem
40 ill-posed problem
8 least squares problem
57 linear programming problem
1 linear programming problem sequence
10 materials problem
2 duplicate materials problem
4 model reduction problem
2 duplicate model reduction problem
18 optimization problem
2 optimization problem sequence
12 power network problem
5 semiconductor device problem
2 statistical/mathematical problem
90 structural problem
8 duplicate structural problem
1 thermal problem

More phrases in Problem.kind may be added later, as matrices are added to the collection. If you parse Problem.kind with a program, unrecognized terms should be ignored.