.. lblGettingStarted:

Initial Setup
=============

Installation
------------

The AMPL API can function as an add-on to any existing AMPL installation.
If you do not yet have an AMPL installation on the computer where you will
be working with the API, see our
`demo page <http://ampl.com/try-ampl/download-a-free-demo/>`_ or
`trial page <http://ampl.com/try-ampl/request-a-full-trial/>`_ to download a
working version that can be installed quickly.

Follow the instructions on our `AMPL API <http://ampl.com/products/api/>`_
page to download the API package appropriate to your platform, and to add
the downloaded folder (directory) ``amplapi`` to your AMPL installation.

Running the examples
--------------------

AMPL API is distributed as one .NET assembly and a native library. They must be both
accessible for the API to work.
A valid Mono .NET or .NET framework configuration is needed to use the .NET AMPL API;
some examples are provided for the user to familiarize with the API; for users of Visual Studio,
some ready-to-use solution files are provided, whilst users of Mono .NET must follow the instructions
or build their own assemblies taking care to reference the assembly provided.

Visual Studio
~~~~~~~~~~~~~

Open the solution file at ``amplapi/examples/csharp/csharp-examples.sln``. Visual Studio 2010 or above are required to open the solution files. The solution file contains all the examples as separate projects.
Note that depending on the architecture of the AMPL API in use (32 bits or 64 bits), the appropriate solution platform should be selected, this is easily achieved using the dropdown in the figure below:

.. figure:: images/visualstudio.*
   :align: center
   :width: 645 px
   :height: 78 px
   :alt: Visual studio configuration
   :figClass: align-center


Mono
~~~~

Windows
+++++++

Note that the csharp examples look for model files in ``..\..\models``, hence they should be compiled in a subdirectory of the path containing them, which must be created. Moreover, they expect ``ampl-csharp.dll`` to be accessible. So, for example:

* Change the current directory to ``amplapi\examples\csharp``
* Create a directory
* Change current directory to the directory created above
* Copy the required assembliy to this directory:
   * The mono assembly ``bin\ampl-csharp.dll``
* Either:
   a. Copy the required libraries to the directory above:

      * The mono/native interface ``bin\csharpswigwrapper.dll``
      * The C++ AMPLAPI library |ampl_so_win|

   b. Add the ``bin`` directory of the AMPL API distribution to the system path

* Compile any of the example files taking care of referencing the API assembly.

* The procedure above is implemented by the script below:

.. code-block:: none

    md bin
    cd bin
    copy ..\..\..\bin\ampl-csharp.dll .
    copy ..\..\..\bin\ampl-2.*.dll .
    copy ..\..\..\bin\csharpswigwrapper.dll .
    mcs /t:exe /out:firstexample /platform:anycpu /sdk:4 /reference:System.dll /reference:ampl-csharp.dll ../FirstExample.cs

To complete an initial test, build ``FirstExample.cs`` using the script above and then invoke it with:

.. code-block:: none

   mono firstexample <modeldir> <solver>

where optionally ``<modeldir>`` is the location of the model files used in the examples
and ``<solver>`` is the name of a solver that has been installed with AMPL
(if a solver is not specified, then AMPL default choice will be used). This will solve
several small diet problems and then display the optimal amounts of the foods
from the last solution.

Note that the folder containing the AMPL executable should be in the system search path.
Otherwise, the error message "AMPL could not be started" will be shown.
If the AMPL installation directory is not in the system search path,
you can add it passing a new  :class:`ampl.Environment` to  :class:`ampl.AMPL` as follows:

.. code-block:: csharp

  ampl.Environment env = new ampl.Environment("full path to the AMPL installation directory");
  ampl.AMPL a = new ampl.AMPL(env);

Note that you may need to escape backslashes (e.g., "C:\\\\ampl\\\\ampl.mswin64") if included in the path.


Linux / macOS
+++++++++++++

Note that the csharp examples look for model files in ``../../models``, hence they should be compiled in a subdirectory of the path containing them, which must be created. Moreover, they expect ``ampl-csharp.dll`` to be accessible. So, for example:

* Change the current directory to ``amplapi/examples/csharp``
* Create a directory
* Change current directory to the directory created above
* Copy the mono assembly ``bin/ampl-csharp.dll`` to this directory.
* Adjust the environment variable ``LD_LIBRARY_PATH`` (or ``DYLD_LIBRARY_PATH`` for macOS)  to look for the dynamic libraries in the correct directory
* Compile any of the example files taking care of referencing the API assembly

* The procedure above is implemented by the script below:

    .. code-block:: none

            mkdir bin
            cd bin
            cp ../../../bin/ampl-csharp.dll .
            export LD_LIBRARY_PATH=$PWD/../../../lib:$LD_LIBRARY_PATH # for Linux
            export DYLD_LIBRARY_PATH=$PWD/../../../lib:$DYLD_LIBRARY_PATH # for macOS
            mcs /t:exe /out:firstexample /platform:anycpu /sdk:4 /reference:System.dll /reference:./ampl-csharp.dll ../FirstExample.cs


To complete an initial test, build ``FirstExample.cs`` using the script above and then invoke it with:

.. code-block:: none

   mono firstexample <modeldir> <solver>

where optionally ``<modeldir>`` is the location of the model files used in the examples
and ``<solver>`` is the name of a solver that has been installed with AMPL
(if a solver is not specified, then AMPL default choice will be used). This will solve
several small diet problems and then display the optimal amounts of the foods
from the last solution. If some libraries are not found, see the note on ``LD_LIBRARY_PATH`` in the next section.

Development
-----------

Reference the assembly ``bin/ampl-csharp.dll`` in your C# project. The binary files that must be accessible are platform dependent and listed below, using the main amplapi directory as root:

* Windows:
    * ``bin\csharpswigwrapper.dll``
    * ``bin\ampl-csharp.dll``
    * |ampl_so_win|

* Linux/Unix:
    * ``bin/ampl-csharp.dll``
    * ``lib/libcsharpswigwrapper.so``
    * |ampl_so_linux| on Linux or |ampl_so_osx| on macOS

Together with your existing AMPL implementation, this will provide the full object library and access to all AMPL functions.

The `amplapi` folder (directory) can be moved to a different location in your computer’s filesystem, provided that the location of your AMPL executable has been placed in the system search path.
In Unix/Linux environments, note that the environment variable ``LD_LIBRARY_PATH`` (or ``DYLD_LIBRARY_PATH`` for macOS) may need to be set appropriately.
To search for the libraries in the current directory, on Linux execute ``export LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH``, on macOS execute
``export DYLD_LIBRARY_PATH=$PWD:$DYLD_LIBRARY_PATH``





Deployment
----------

To deploy AMPL API applications to users who do not have their own AMPL installations, include with your C# application the AMPL executable
(``ampl`` or ``ampl.exe``), the additional files listed in the previous section, the binaries needed to run any solvers that are used and
an appropriate license file for AMPL and solvers.