Installation and Licensing#
Basic Installation#
You can run the following command to install GAMSPy from PyPI:
pip install gamspy
Licensing#
GAMSPy comes with a free demo license which lets you generate and solve small models. For more information about GAMS licenses and how to get a new license, check GAMS Licensing.
Installing or updating your license#
A GAMSPy license is a either an ASCII file of six lines or 36 character identification number sent to you via e-mail. In order to install your license, all you need to do is to run:
gamspy install license <path_to_ascii_file or identification number>
For machines that are not connected to the internet, you can install a license with the node information by running:
gamspy install license -i <your_license_number>
This option is available only for licenses in identification number format.
Note
GAMS and GAMSPy licenses are different, which means one cannot use an existing GAMS license for GAMSPy. We provide GAMSPy licenses for free if you already have a full GAMS license. Contact sales@gams.com (with your GAMS license) to arrange for the delivery of a GAMSPy license. If you were using a GAMS license for GAMSPy before v0.13.0, please contact sales@gams.com to arrange a GAMSPy license.
Uninstalling your license#
If you no longer wish to use your license, you can uninstall it with the following command:
gamspy uninstall license
License installation for offline machines#
In order to use GAMSPy in a machine which does not have an internet connection (offline), the license installation process is as follows:
Generate a json file which contains the node information as follows:
gamspy probe -o info.json
Move info.json file to a machine which has an internet connection and run:
gamspy retrieve license <your_license_id> -i info.json -o license.txt
Move license.txt to the machine that does not have an internet connection and run:
gamspy install license license.txt
GAMS/Gurobi-Link#
Attempting to use the GAMS/Gurobi solver with a GAMS/Gurobi-Link license but without a properly set up Gurobi license will result in a licensing error with a message describing the problem. To make the GAMS/Gurobi-Link work you do not need to download or install the Gurobi software but only your Gurobi license.
You only need to set the GRB_LICENSE_FILE environment variable to the path of the Gurobi
license (gurobi.lic) that you generated using the grbgetkey program:
export GRB_LICENSE_FILE=/path/to/gurobi.lic
Then, you can run the gamspy command as usual:
gamspy install license <path_to_your_license_file>
Note
To use Gurobi to solve your model, remember to specify the solver argument
in the model.solve.
your model definition
…
…
model.solve(solver=”gurobi”)
Solvers#
GAMSPy comes with default solvers, and additional solvers can be installed on demand.
Listing Solvers#
To list the installed solvers on your machine, you can run either:
gamspy list solvers
Alternatively, if you want to list all available solvers, you can run the following:
gamspy list solvers --all
The same information can also be accessed programmatically via the utils module of GAMSPy:
import gamspy as gp
import gamspy_base
print(gp.utils.getInstalledSolvers(gamspy_base.directory))
print(gp.utils.getAvailableSolvers())
Note
All available solver packages can also be found on PyPI.
Installing/Uninstalling New Solvers#
TThe following command can be used to install new solvers:
gamspy install solver <solver_name>
Similarly, a solver can be uninstalled using:
gamspy uninstall solver <solver_name>
Updating Solvers#
If the solvers on your machine are not up-to-date, you can run:
gamspy update
This will update all solvers to a version compatible with GAMSPy.
Building from source#
If you are a macOS or Linux user (or using a subsystem like WSL on Windows) familiar with the command line, you can build GAMSPy locally by following the instructions below.
Prerequisites#
Building GAMSPy requires the following software to be installed:
Python 3.8.x or newer
The GAMSPy source code:
git clone git@github.com:GAMS-dev/gamspy.git
Installation#
You can install GAMSPy from source using the following command:
pip install .
Testing#
Tests are classified into three categories: unit tests, integration tests, and doc tests. The tests can be run with:
python tests/test_gamspy.py
Note
By default, only unit tests are run. To enable integration tests, the --integration argument should be provided.
Doctests can be enable with the --doc argument.