Module: LPSolve

Extended by:
FFI::Library
Defined in:
lib/lp_select/lp_solve.rb

Overview

This module uses Ruby's DL library to dynamically load
the liblpsolve library, which is a linear equation solver.

The sourceforge summary says:
Mixed Integer Linear Programming (MILP) solver lp_solve solves pure linear, 
(mixed) integer/binary, semi-cont and special ordered sets (SOS) models.  
lp_solve is written in ANSI C and can be compiled on many different platforms 
like Linux and WINDOWS

Read more at http://sourceforge.net/projects/lpsolve/

This module mostly serves to load the file and attach to the 
API functions

Constant Summary collapse

LE =

Constants used when assigning constraints

1
EQ =

<=

3
GE = 

2
CRITICAL =

Constants used for verbosity

1
SEVERE = 
2
IMPORTANT = 
3
NORMAL = 
4
DETAILED = 
5
FULL = 
6
NOMEMORY =

Constants used for solve results

-2
OPTIMAL = 
0
SUBOPTIMAL = 
1
INFEASIBLE = 
2
UNBOUNDED = 
3
DEGENERATE = 
4
NUMFAILURE = 
5
USERABORT = 
6
TIMEOUT = 
7
PRESOLVED = 
9
PROCFAIL = 
10
PROCBREAK = 
11
FEASFOUND = 
12
NOFEASFOUND = 
13

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.version ⇒ Object 



144
145
146
147
148
149
150
151
152
 
# File 'lib/lp_select/lp_solve.rb', line 144

def self.version
  maj_ptr = FFI::MemoryPointer.new(:pointer, 1)
  min_ptr = FFI::MemoryPointer.new(:pointer, 1)
  rel_ptr = FFI::MemoryPointer.new(:pointer, 1)
  bld_ptr = FFI::MemoryPointer.new(:pointer, 1)
  LPSolve::lp_solve_version(maj_ptr, min_ptr, rel_ptr, bld_ptr)
  
  "#{maj_ptr.read_int}.#{min_ptr.read_int}.#{rel_ptr.read_int} build #{bld_ptr.read_int}"
end

Instance Method Details

#op_to_s(op_int) ⇒ Object

>=



39
40
41
42
43
44
45
 
# File 'lib/lp_select/lp_solve.rb', line 39

def op_to_s(op_int)
  case op_int
    when LPSelect::GE then ">="
    when LPSelect::LE then "<=" 
    when LPSelect::EQ then "=="
  end
end