The NONZ, or NONZEROS, command displays an abbreviated version of the solution for the current model. NONZ is identical to the SOLUTION command with the exception that NONZ displays information only about nonzero variables and binding rows (i.e., the slack or surplus is 0).

The syntax of the NONZ command is:

NONZ ['header_text'] [var_or_row_names]

For a standard NONZ solution report, omit the two optional arguments and enter the NONZ command by itself. LINGO will print primal and dual values for all nonzero variables and binding rows. LINGO will label all the columns in the report.

The first optional field, header_text, will be displayed as a title header in the solution report. If the header_text argument is included, LINGO prints primal values only, omitting all labels in the report.

The second optional field, var_or_row_names, is a variable and/or row name list that, if included, will limit the report to the given variables or rows.  The standard wild card characters (* and %) are supported in the variable and row names.

As an example, in the following session, we load the Chess Snackfoods example from the Using Sets section and then generate several solution reports using NONZ:

: TAKE CHESS.LNG

: TERSE

: GO

 

Global optimal solution found at step:         0

Objective value:                        2692.308

 

: !Generate a standard NONZ report

: NONZ

 

                 Variable      Value  Reduced Cost

         SUPPLY( PEANUTS)   750.0000      0.000000

         SUPPLY( CASHEWS)   250.0000      0.000000

             PRICE( PAWN)   2.000000      0.000000

           PRICE( KNIGHT)   3.000000      0.000000

           PRICE( BISHOP)   4.000000      0.000000

             PRICE( KING)   5.000000      0.000000

           PRODUCE( PAWN)   769.2308      0.000000

           PRODUCE( KING)   230.7692      0.000000

  FORMULA( PEANUTS, PAWN)   15.00000      0.000000

FORMULA( PEANUTS, KNIGHT)   10.00000      0.000000

FORMULA( PEANUTS, BISHOP)   6.000000      0.000000

  FORMULA( PEANUTS, KING)   2.000000      0.000000

  FORMULA( CASHEWS, PAWN)   1.000000      0.000000

FORMULA( CASHEWS, KNIGHT)   6.000000      0.000000

FORMULA( CASHEWS, BISHOP)   10.00000      0.000000

  FORMULA( CASHEWS, KING)   14.00000      0.000000

 

             Row    Slack or Surplus    Dual Price

               1            2692.308      1.000000

               2            0.000000      1.769231

               3            0.000000      5.461538

 

: !Generate a NONZ report for PRODUCE

: NONZ PRODUCE

 

                 Variable      Value  Reduced Cost

           PRODUCE( PAWN)   769.2308      0.000000

           PRODUCE( KING)   230.7692      0.000000

 

: !Now add a header and use a wildcard in the name

: NONZ 'NONZERO PRODUCTION VALUES:' PROD*

 

NONZERO PRODUCTION VALUES:

        769.2308

        230.7692

If you would like to capture the solution report in a file, use the DIVERT command before the NONZ command.

For more information on the interpretation of the various fields in the NONZEROS report, see Getting Started with LINGO.