Below here is a draft description of dimacs-like format to represent lp/mip problem data. Text files in this format are human-readable and suitable for processing with text tools like sed, gawk, etc., so this format can be used in glpk as a basic low-level format.
Any comments are appreciated. Thanks. Andrew Makhorin LP/MIP problem data in DIMACS-like format ***************************************** Comment line ------------ c arbitrary text Problem descriptor line ----------------------- p lp ROWS COLS NONZ LP problem p mip ROWS COLS NONZ MIP problem ROWS is the number of rows COLS is the number of columns NONZ is the number of non-zero constraint coefficients Row descriptor line ------------------- r ROW f free (unbounded) row r ROW l RHS inequality of '>=' type r ROW u RHS inequality of '<=' type r ROW d RHS1 RHS2 double-sided inequality r ROW s RHS equality ROW is row ordinal number (1 to ROWS) RHS is right-hand side Column descriptor line ---------------------- x COL f free (unbounded) column x COL l BND column with (non-zero) lower bound x COL u BND column with upper bound x COL d BND1 BND2 double-bounded column x COL s BND fixed column COL is column ordinal number (1 to COLS) BND is column bound/fixed value Column kind descriptor line (ignored for LP) -------------------------------------------- k COL c continuous column (default) k COL i integer column k COL b binary column COL is column ordinal number (1 to COLS) Objective/constraint coefficient descriptor line ------------------------------------------------ a 0 COL COEF objective coefficient a ROW COL COEF constraint coefficient ROW is row ordinal number (1 to ROWS) COL is column ordinal number (1 to COLS) COEF is (non-zero) coefficient value Symbolic name descriptor line ----------------------------- n p NAME problem name n z NAME objective function name n r ROW NAME row name n x COL NAME column name ROW is row ordinal number (1 to ROWS) COL is column ordinal number (1 to COLS) NAME is symbolic name (1 to 255 chars) _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
