Description: Netlib LP problem modszk1: minimize c'*x, where Ax=b, lo<=x<=hi
|(bipartite graph drawing)|
|number of rows||687|
|number of columns||1,620|
|structural full rank?||no|
|# of blocks from dmperm||3|
|# strongly connected comp.||3|
|explicit zero entries||0|
|nonzero pattern symmetry||0%|
|numeric value symmetry||0%|
|kind||linear programming problem|
|Additional fields||size and type|
A Netlib LP problem, in lp/data. For more information send email to email@example.com with the message: send index from lp send readme from lp/data The following are relevant excerpts from lp/data/readme (by David M. Gay): The column and nonzero counts in the PROBLEM SUMMARY TABLE below exclude slack and surplus columns and the right-hand side vector, but include the cost row. We have omitted other free rows and all but the first right-hand side vector, as noted below. The byte count is for the MPS compressed file; it includes a newline character at the end of each line. These files start with a blank initial line intended to prevent mail programs from discarding any of the data. The BR column indicates whether a problem has bounds or ranges: B stands for "has bounds", R for "has ranges". The BOUND-TYPE TABLE below shows the bound types present in those problems that have bounds. The optimal value is from MINOS version 5.3 (of Sept. 1988) running on a VAX with default options. PROBLEM SUMMARY TABLE Name Rows Cols Nonzeros Bytes BR Optimal Value MODSZK1 688 1620 4158 40908 B 3.2061972906E+02 BOUND-TYPE TABLE MODSZK1 FR From Istvan Maros. Concerning the problems he submitted, Istvan Maros says that MODSZK1 is a "real-life problem" that is "very degenerate" and on which a dual simplex algorithm "may require up to 10 times" fewer iterations than a primal simplex algorithm. It "is a multi-sector economic planning model (a kind of an input/output model in economy)" and "is an old problem of mine and it is not easy to recall more." Added to Netlib on 17 Jan. 1994
|nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD||71,390|
|nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD||12,434|
|null space dimension||1|
|full numerical rank?||no|
|singular value gap||1.32806e+18|
|singular values (MAT file):||click here|
|SVD method used:||s = svd (full (A)) ;|
For a description of the statistics displayed above, click here.
Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.