Re: [Help-glpk] lp/mip problem data in dimacs-like format

[Noli Sicad]

Andrew,

Would it be possible to have a simple example on this new dimacs like
data format? I presumed that this new format only applies to GLPK, not
on MathProg. An example will be easy to visualise the new data format,
in my case.

Noli


On 1/7/10, Andrew Makhorin <address@hidden> wrote:
> 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)
>
>
>
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