The LP Procedure
- Overview
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Getting Started
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Syntax
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Details
Missing Values Dense Data Input Format Sparse Data Input Format Converting Any PROC LP Format to an MPS-Format SAS Data Set Converting Standard MPS Format to Sparse Format The Reduced Costs, Dual Activities, and Current Tableau Macro Variable ORLP Pricing Scaling Preprocessing Integer Programming Sensitivity Analysis Range Analysis Parametric Programming Interactive Facilities Memory Management Output Data Sets Input Data Sets Displayed Output ODS Table and Variable Names Memory Limit
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Examples
An Oil Blending Problem A Sparse View of the Oil Blending Problem Sensitivity Analysis: Changes in Objective Coefficients Additional Sensitivity Analysis Price Parametric Programming for the Oil Blending Problem Special Ordered Sets and the Oil Blending Problem Goal-Programming a Product Mix Problem A Simple Integer Program An Infeasible Problem Restarting an Integer Program Alternative Search of the Branch-and-Bound Tree An Assignment Problem A Scheduling Problem A Multicommodity Transshipment Problem with Fixed Charges Converting to an MPS-Format SAS Data Set Migration to OPTMODEL: Assignment Migration to OPTMODEL: Multicommodity Transshipment
- References
| Macro Variable _ORLP_ |
The LP procedure defines a macro variable named _ORLP_. This variable contains a character string that indicates the status of the procedure. It is set whenever the user gets control, at breakpoints, and at procedure termination. The form of the _ORLP_ character string is STATUS= PHASE= OBJECTIVE= P_FEAS= D_FEAS= INT_ITER= INT_FEAS= ACTIVE= INT_BEST= PHASE1_ITER= PHASE2_ITER= PHASE3_ITER=. The terms are interpreted as follows:
STATUS= |
the status of the current solution |
PHASE= |
the phase the procedure is in (1, 2, or 3) |
OBJECTIVE= |
the current objective value |
P_FEAS= |
whether the current solution is primal feasible |
D_FEAS= |
whether the current solution is dual feasible |
INT_ITER= |
the number of integer iterations performed |
INT_FEAS= |
the number of integer feasible solutions found |
ACTIVE= |
the number of active nodes in the current branch-and-bound tree |
INT_BEST= |
the best integer objective value found |
PHASE1_ITER= |
the number of iterations performed in phase 1 |
PHASE2_ITER= |
the number of iterations performed in phase 2 |
PHASE3_ITER= |
the number of iterations performed in phase 3 |
Table 5.5 shows the possible values for the nonnumeric terms in the string.
STATUS= |
P_FEAS= |
D_FEAS= |
SUCCESSFUL |
YES |
YES |
UNBOUNDED |
NO |
NO |
INFEASIBLE |
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MAX_TIME |
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MAX_ITER |
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PIVOT |
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BREAK |
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INT_FEASIBLE |
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INT_INFEASIBLE |
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INT_MAX_ITER |
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PAUSE |
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FEASIBLEPAUSE |
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IPAUSE |
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PROXIMITYPAUSE |
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ACTIVE |
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RELAXED |
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FATHOMED |
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IPIVOT |
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UNSTABLE |
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SINGULAR |
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MEMORY_ERROR |
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IO_ERROR |
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SYNTAX_ERROR |
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SEMANTIC_ERROR |
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BADDATA_ERROR |
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UNKNOWN_ERROR |
This information can be used when PROC LP is one step in a larger program that needs to identify how the LP procedure terminated. Because _ORLP_ is a standard SAS macro variable, it can be used in the ways that all macro variables can be used (see the SAS Guide to Macro Processing).