Functions
def	get_master_model ()

def	get_sub_model ()

Variables
	ws = GamsWorkspace(system_directory = sys.argv[1])

	opt = ws.add_options()

	cutstock_data = ws.add_database("csdata")

	all_model_types

	optcr

int	maxpattern = 35

dictionary	d = {"i1": 97, "i2": 610, "i3":395, "i4": 211}

dictionary	w = {"i1": 47, "i2": 36, "i3": 31, "i4": 14}

int	r = 100

	widths = cutstock_data.add_set("i", 1, "widths")

	raw_width = cutstock_data.add_parameter("r", 0, "raw width")

	demand = cutstock_data.add_parameter("d", 1, "demand")

	width = cutstock_data.add_parameter("w", 1, "width")

	value

	master_cp = ws.add_checkpoint()

	master_init_job = ws.add_job_from_string(get_master_model())

	databases

	master_job = ws.add_job_from_string("execute_load 'csdata', aip, pp; solve master min z using %solveMasterAs%;", master_cp)

	pattern = cutstock_data.add_set("pp", 1, "pattern index")

	pattern_data = cutstock_data.add_parameter("aip", 2, "pattern data")

int	pattern_count = 0

	sub_cp = ws.add_checkpoint()

	sub_job = ws.add_job_from_string(get_sub_model())

	sub_mi = sub_cp.add_modelinstance()

	demand_dual = sub_mi.sync_db.add_parameter("demdual", 1, "dual of demand from master")

bool	pattern_added = True

	s = pattern.add_record(str(pattern_count))

	end

	aip = master_job.out_db["aip"].first_record((" ", xp.key(0)))

Function Documentation

◆ get_master_model()

def cutstock.get_master_model ( )

Definition at line 14 of file cutstock.py.

def get_master_model():
     return '''
 $Title Cutting Stock - Master problem
  
 Set  i    widths
 Parameter
      w(i) width
      d(i) demand
 Scalar
      r    raw width;
 $gdxin csdata
 $load i w d r
  
 $if not set pmax $set pmax 1000
 Set  p        possible patterns  /1*%pmax%/
      pp(p)    dynamic subset of p
 Parameter
      aip(i,p) number of width i in pattern growing in p;
  
 * Master model
 Variable xp(p)     patterns used
          z         objective variable
 Integer variable xp; xp.up(p) = sum(i, d(i));
  
 Equation numpat;    numpat..    z =e= sum(pp, xp(pp));
 Equation demand(i); demand(i).. sum(pp, aip(i,pp)*xp(pp)) =g= d(i);
  
 model master /numpat, demand/;'''
  

◆ get_sub_model()

def cutstock.get_sub_model ( )

Definition at line 43 of file cutstock.py.

Variable Documentation

◆ aip

cutstock.aip = master_job.out_db["aip"].first_record((" ", xp.key(0)))

Definition at line 155 of file cutstock.py.

◆ all_model_types

cutstock.all_model_types

Definition at line 76 of file cutstock.py.

◆ cutstock_data

cutstock.cutstock_data = ws.add_database("csdata")

Definition at line 75 of file cutstock.py.

◆ d

dictionary cutstock.d = {"i1": 97, "i2": 610, "i3":395, "i4": 211}

Definition at line 83 of file cutstock.py.

◆ databases

cutstock.databases

Definition at line 102 of file cutstock.py.

◆ demand

cutstock.demand = cutstock_data.add_parameter("d", 1, "demand")

Definition at line 89 of file cutstock.py.

◆ demand_dual

cutstock.demand_dual = sub_mi.sync_db.add_parameter("demdual", 1, "dual of demand from master")

Definition at line 120 of file cutstock.py.

◆ end

cutstock.end

Definition at line 154 of file cutstock.py.

◆ master_cp

cutstock.master_cp = ws.add_checkpoint()

Definition at line 100 of file cutstock.py.

◆ master_init_job

cutstock.master_init_job = ws.add_job_from_string(get_master_model())

Definition at line 101 of file cutstock.py.

◆ master_job

cutstock.master_job = ws.add_job_from_string("execute_load 'csdata', aip, pp; solve master min z using %solveMasterAs%;", master_cp)

Definition at line 103 of file cutstock.py.

◆ maxpattern

int cutstock.maxpattern = 35

Definition at line 78 of file cutstock.py.

◆ opt

cutstock.opt = ws.add_options()

Definition at line 74 of file cutstock.py.

◆ optcr

cutstock.optcr

Definition at line 77 of file cutstock.py.

◆ pattern

cutstock.pattern = cutstock_data.add_set("pp", 1, "pattern index")

Definition at line 105 of file cutstock.py.

◆ pattern_added

bool cutstock.pattern_added = True

Definition at line 124 of file cutstock.py.

◆ pattern_count

int cutstock.pattern_count = 0

Definition at line 109 of file cutstock.py.

◆ pattern_data

cutstock.pattern_data = cutstock_data.add_parameter("aip", 2, "pattern data")

Definition at line 106 of file cutstock.py.

◆ r

int cutstock.r = 100

Definition at line 85 of file cutstock.py.

◆ raw_width

cutstock.raw_width = cutstock_data.add_parameter("r", 0, "raw width")

Definition at line 88 of file cutstock.py.

◆ s

cutstock.s = pattern.add_record(str(pattern_count))

Definition at line 140 of file cutstock.py.

◆ sub_cp

cutstock.sub_cp = ws.add_checkpoint()

Definition at line 114 of file cutstock.py.

◆ sub_job

cutstock.sub_job = ws.add_job_from_string(get_sub_model())

Definition at line 115 of file cutstock.py.

◆ sub_mi

cutstock.sub_mi = sub_cp.add_modelinstance()

Definition at line 117 of file cutstock.py.

◆ value

cutstock.value

Definition at line 92 of file cutstock.py.

◆ w

dictionary cutstock.w = {"i1": 47, "i2": 36, "i3": 31, "i4": 14}

Definition at line 84 of file cutstock.py.

◆ width

cutstock.width = cutstock_data.add_parameter("w", 1, "width")

Definition at line 90 of file cutstock.py.

◆ widths

cutstock.widths = cutstock_data.add_set("i", 1, "widths")

Definition at line 87 of file cutstock.py.

◆ ws

cutstock.ws = GamsWorkspace(system_directory = sys.argv[1])

Definition at line 70 of file cutstock.py.

Functions

Variables