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).
where Group/Name is the first problem in the sequence (the same as the Problem with kind = 'sequence'). The next Problem in the sequence is given by the name "Group2/Name2". This method is used only for Problems with Problem.id of 1377 or less (matrices added after March 2006).
where Group/Name is the first Problem in the sequence, and Group2/Name2 is the next Problem after this one, or "-" if this Problem is the last member of the sequence. The word "subsequent" always appears at the end of the string. This keyword is used only for problems added on March 2006 or before (problems 1 to 1377).
# problems | kind |
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.