The GamsWorkspace is the base class of the gams.control API. More...

Public Member Functions
def	get_eps (self)
	Reset value to be stored in and read from GamsDatabase for Epsilon.

def	__init__ (self, working_directory=None, system_directory=None, debug=DebugLevel.KeepFilesOnError)
	constructor

def	gamslib (self, model)
	Retrieves model from GAMS Model Library.

def	testlib (self, model)
	Retrieves model from GAMS Test Library.

def	emplib (self, model)
	Retrieves model from Extended Math Programming Library.

def	datalib (self, model)
	Retrieves model from GAMS Data Utilities Library.

def	finlib (self, model)
	Retrieves model from Practical Financial Optimization Library.

def	noalib (self, model)
	Retrieves model from Nonlinear Optimization Applications Using the GAMS Technology Library.

def	psoptlib (self, model)
	Retrieves model from Power System Optimization Modelling Library.

def	apilib (self, model)
	Retrieves model from GAMS API Library.

def	add_database (self, database_name=None, source_database=None, in_model_name=None)
	Database creation.

def	add_database_from_gdx (self, gdx_file_name, database_name=None, in_model_name=None)
	Database creation from an existing GDX file.

def	add_job_from_string (self, gams_source, checkpoint=None, job_name=None)
	Create GamsJob from string model source.

def	add_job_from_file (self, file_name, checkpoint=None, job_name=None)
	Create GamsJob from model file.

def	add_job_from_gamslib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS Model Library.

def	add_job_from_testlib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS Test Library.

def	add_job_from_apilib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS API Library.

def	add_job_from_emplib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS Extended Math Programming Library.

def	add_job_from_datalib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS Data Utilities Library.

def	add_job_from_finlib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from Practical Financial Optimization Library.

def	add_job_from_noalib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from GAMS Non-linear Optimization Applications Library.

def	add_job_from_psoptlib (self, model, checkpoint=None, job_name=None)
	Create GamsJob from model from Power System Optimization Modelling Library.

def	add_options (self, gams_options_from=None, opt_file=None)
	Create GamsOptions.

def	add_checkpoint (self, checkpoint_name=None)
	Create GamsCheckpoint.

Public Attributes
	scratch_file_prefix
	A string used to prefix automatically generated files.

Static Public Attributes
GamsOptions	api_version = GamsOptions._api_ver
	GAMS API version.

int	api_major_rel_number = int(GamsOptions._api_ver.split(".")[0])
	GAMS API Major Release Number.

int	api_minor_rel_number = int(GamsOptions._api_ver.split(".")[1])
	GAMS API Minor Release Number.

int	api_gold_rel_number = int(GamsOptions._api_ver.split(".")[2])
	GAMS API GOLD Release Number.

Protected Member Functions
def	_add_database_from_gmd (self, gmd_handle, database_name=None, in_model_name=None)

Properties
property	my_eps = property(get_eps, set_eps)
	Get value to be stored in and read from GamsDatabase for Epsilon.

property	working_directory = property(get_working_directory)
	GAMS working directory, anchor for all file-based operations.

property	system_directory = property(get_system_directory)
	GAMS system directory.

property	version = property(get_version)
	GAMS Version used.

property	major_rel_number = property(get_major_rel_number)
	GAMS Major Release Number.

property	minor_rel_number = property(get_minor_rel_number)
	GAMS Minor Release Number.

property	gold_rel_number = property(get_gold_rel_number)
	GAMS GOLD Release Number.

Detailed Description

The GamsWorkspace is the base class of the gams.control API.

Most objects of the control API (e.g. GamsDatabase and GamsJob) should be created by an "add" method of GamsWorkspace instead of using the constructors.

Unless a GAMS system directory is specified during construction of GamsWorkspace, GamsWorkspace determines the location of the GAMS installation automatically. This is a source of potential problems if more than one GAMS installation exist on the machine.

Furthermore, a working directory (the anchor into the file system) can be provided when constructing the GamsWorkspace instance. All file based operation inside a GAMS model should be relative to this location (e.g. $GDXIN and $include). There are options to add input search paths (e.g. IDir) and output path (e.g. PutDir) to specify other file system locations. If no working directory is supplied, GamsWorkspace creates a temporary folder and on instance destruction removes this temporary folder.

In a typical Python application a single instance of GamsWorkspace will suffice, since the class is thread-safe.

Working with different GAMS Versions on one Machine

When creating a new instance of GamsWorkspace, one way of defining the GAMS system directory is setting the system_directory parameter of the constructor accordingly. If it is not set, it is tried to be defined automatically (see Control for details). However, this can be tricky if there is more than one version of GAMS installed on a machine and especially if there are different applications running with different GAMS versions.

On Windows, the automatic identification relies on information left in the Windows registry by the GAMS installer. Hence the system directory of the last GAMS installation will be found in this automatic identification step. One way of resetting the information in the registry is running the executable "findthisgams.exe" from the directory that should be detected automatically. While this can be done from the outside of the application it is not much more convenient than the system_directory argument in the GamsWorkspace constructor.

If one has a very structured way of organizing the GAMS installations (e.g. following the GAMS default installation location) one can use GamsWorkspace.api_version to point to the best matching GAMS system directory:

sysdir = "C:\\GAMS\\" + GamsWorkspace.api_version[:2]

ws = GamsWorkspace(system_directory=sysdir)

This avoids the automatic identification of the GAMS system directory but might be the most convenient solution for systems running multiple applications using different versions of the GAMS Python API together with different versions of GAMS.

Constructor & Destructor Documentation

◆ init()

def gams.control.workspace.GamsWorkspace.__init__	(	self,
		working_directory = `None`,
		system_directory = `None`,
		debug = `DebugLevel.KeepFilesOnError`
	)

constructor

Parameters

working_directory	GAMS working directory, anchor for all file-based operations (determined automatically if omitted, in user's temporary folder)
system_directory	GAMS system directory (determined automatically if omitted)
debug	Debug Flag (default: DebugLevel.KeepFilesOnError)

Member Function Documentation

◆ _add_database_from_gmd()

def gams.control.workspace.GamsWorkspace._add_database_from_gmd	(	self,
		gmd_handle,
		database_name = `None`,
		in_model_name = `None`
	)

protected

   @brief Database creation from an existing GMD handle. This will alter setting for special values and debug settings using the functions: gmdSetDebug and gmdSetSpecialValues. Meant for internal use only
   @param gmd_handle The already created and initialised GMD handle
   @param database_name Identifier of GamsDatabase (determined automatically if omitted)
   @param in_model_name GAMS string constant that is used to access this database
   @return Instance of type GamsDatabase

◆ add_checkpoint()

def gams.control.workspace.GamsWorkspace.add_checkpoint	(	self,
		checkpoint_name = `None`
	)

Create GamsCheckpoint.

Parameters

checkpoint_name checkpoint_name Identifier of GamsCheckpoint or filename for existing checkpoint (determined automatically if omitted)

Returns: GamsCheckpoint instance

◆ add_database()

def gams.control.workspace.GamsWorkspace.add_database	(	self,
		database_name = `None`,
		source_database = `None`,
		in_model_name = `None`
	)

Database creation.

Parameters

database_name	Identifier of GamsDatabase (determined automatically if omitted)
source_database	Source GamsDatabase to initialize Database from (empty Database if omitted)
in_model_name	GAMS string constant that is used to access this database

Returns: Instance of type GamsDatabase

◆ add_database_from_gdx()

def gams.control.workspace.GamsWorkspace.add_database_from_gdx	(	self,
		gdx_file_name,
		database_name = `None`,
		in_model_name = `None`
	)

Database creation from an existing GDX file.

Parameters

gdx_file_name	GDX File to initialize Database from
database_name	Identifier of GamsDatabase (determined automatically if omitted)
in_model_name	GAMS string constant that is used to access this database

Returns: Instance of type GamsDatabase

◆ add_job_from_apilib()

def gams.control.workspace.GamsWorkspace.add_job_from_apilib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS API Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_datalib()

def gams.control.workspace.GamsWorkspace.add_job_from_datalib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS Data Utilities Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_emplib()

def gams.control.workspace.GamsWorkspace.add_job_from_emplib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS Extended Math Programming Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_file()

def gams.control.workspace.GamsWorkspace.add_job_from_file	(	self,
		file_name,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model file.

Parameters

file_name	GAMS source file name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_finlib()

def gams.control.workspace.GamsWorkspace.add_job_from_finlib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from Practical Financial Optimization Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_gamslib()

def gams.control.workspace.GamsWorkspace.add_job_from_gamslib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS Model Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_noalib()

def gams.control.workspace.GamsWorkspace.add_job_from_noalib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS Non-linear Optimization Applications Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_psoptlib()

def gams.control.workspace.GamsWorkspace.add_job_from_psoptlib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from Power System Optimization Modelling Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_string()

def gams.control.workspace.GamsWorkspace.add_job_from_string	(	self,
		gams_source,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from string model source.

Parameters

gams_source	GAMS model as string
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_job_from_testlib()

def gams.control.workspace.GamsWorkspace.add_job_from_testlib	(	self,
		model,
		checkpoint = `None`,
		job_name = `None`
	)

Create GamsJob from model from GAMS Test Library.

Parameters

model	model name
checkpoint	GamsCheckpoint to initialize GamsJob from
job_name	Job name (determined automatically if omitted)

Returns: GamsJob instance

◆ add_options()

def gams.control.workspace.GamsWorkspace.add_options	(	self,
		gams_options_from = `None`,
		opt_file = `None`
	)

Create GamsOptions.

Parameters

gams_options_from	GamsOptions used to initialize the new object
opt_file	Parameter file used to initialize the new object

Returns: GamsOptions instance

◆ apilib()

def gams.control.workspace.GamsWorkspace.apilib	(	self,
		model
	)

Retrieves model from GAMS API Library.

Parameters

model Model name

◆ datalib()

def gams.control.workspace.GamsWorkspace.datalib	(	self,
		model
	)

Retrieves model from GAMS Data Utilities Library.

Parameters

model Model name

◆ emplib()

def gams.control.workspace.GamsWorkspace.emplib	(	self,
		model
	)

Retrieves model from Extended Math Programming Library.

Parameters

model Model name

◆ finlib()

def gams.control.workspace.GamsWorkspace.finlib	(	self,
		model
	)

Retrieves model from Practical Financial Optimization Library.

Parameters

model Model name

◆ gamslib()

def gams.control.workspace.GamsWorkspace.gamslib	(	self,
		model
	)

Retrieves model from GAMS Model Library.

Parameters

model Model name

◆ noalib()

def gams.control.workspace.GamsWorkspace.noalib	(	self,
		model
	)

Retrieves model from Nonlinear Optimization Applications Using the GAMS Technology Library.

Parameters

model Model name

◆ psoptlib()

def gams.control.workspace.GamsWorkspace.psoptlib	(	self,
		model
	)

Retrieves model from Power System Optimization Modelling Library.

Parameters

model Model name

◆ testlib()

def gams.control.workspace.GamsWorkspace.testlib	(	self,
		model
	)

Retrieves model from GAMS Test Library.

Parameters

model Model name

Public Member Functions

Public Attributes

Static Public Attributes

Protected Member Functions

Properties

Detailed Description

Working with different GAMS Versions on one Machine

Constructor & Destructor Documentation

◆ __init__()

Member Function Documentation

◆ _add_database_from_gmd()

◆ add_checkpoint()

◆ add_database()

◆ add_database_from_gdx()

◆ add_job_from_apilib()

◆ add_job_from_datalib()

◆ add_job_from_emplib()

◆ add_job_from_file()

◆ add_job_from_finlib()

◆ add_job_from_gamslib()

◆ add_job_from_noalib()

◆ add_job_from_psoptlib()

◆ add_job_from_string()

◆ add_job_from_testlib()

◆ add_options()

◆ apilib()

◆ datalib()

◆ emplib()

◆ finlib()

◆ gamslib()

◆ noalib()

◆ psoptlib()

◆ testlib()

◆ init()