Utilites
^^^^^^^^

GNA tools
"""""""""

GNA contains a set of helper tools to simplify calling C++ functions from python. The :ref:`Constructors` module contain
wrappers for often used C++ classes' enabling the user to pass numpy arrays and python lists. The following code
converts the python list of strings to ``std::vector<std::string>``:

.. literalinclude:: ../../../macro/tutorial/basic/00_stdvector.py
    :linenos:
    :lines: 3-
    :emphasize-lines: 3
    :caption: :download:`00_stdvector.py <../../../macro/tutorial/basic/00_stdvector.py>`

The code produces the following output:

.. code-block:: text
    :linenos:

    { "str1", "str2", "str3" } ['str1', 'str2', 'str3']

GNA introduces convenience pythonic methods for its types that may be loaded as follows:

.. code-block:: python

    from gna.bindings import common

They include the methods for printing and plotting with matplotlib.

Tutorial functions
""""""""""""""""""

We will use the function `tutorial_image_name()` to generate the proper names for output images.
The names will be printed to the output. The function call may be replaced by a simple string.

Tutorial options
""""""""""""""""

The tutorial may be executed in batch mode that disables GUI windows. In order to enable it use ``--batch`` command line
option:

.. code-block:: bash

    ./macro/tutorial/plotting/04_points_plot.py --batch

The batch mode will be triggered automatically in case ``$DISPLAY`` environment variable is not set.