|image0|

.. |image0| image:: LevelDiagramLogo150.png

Introduction
============

.. code:: ipython3

    %matplotlib inline

.. code:: ipython3

    import networkx as nx
    import leveldiagram as ld

To begin, the system is defined using a directional graph, provided by
the networkx.DiGraph class. The nodes of this graph represent the
levels, the edges represent the desired couplings.

Passing a simple graph to the base level diagram constructor LD will
produce a passable output for simple visualization.

.. code:: ipython3

    nodes = (0,1,2)
    edges = ((0,1),(1,2))
    graph = nx.DiGraph()
    graph.add_nodes_from(nodes)
    graph.add_edges_from(edges)

.. code:: ipython3

    d = ld.LD(graph)
    d.draw()
    d.fig.savefig('basic_example.png', bbox_inches='tight', dpi=150)



.. image:: output_6_0.png


In keeping with peak matplotlib form, getting something that looks nicer
requires applying custom configuration settings that control many of the
aspects of the diagram.

Gloabl settings can be controlled by passing in keyword argument
dictionaries to the constructor.

.. code:: ipython3

    d = ld.LD(graph, coupling_defaults = {'arrowsize':0.2,'lw':3})
    d.draw()



.. image:: output_9_0.png


NetworkX graphs take an internal structure of nested dictionaries.
Leveldiagram utilizes this to provide keyword argument control over each
element in the graph.

.. code:: ipython3

    from collections import namedtuple
    r_state = namedtuple('r_state', ['n','l','j'])

.. code:: ipython3

    g = 'g'
    e = 'e'
    r = r_state(50, 2, 2.5)
    nodes = ((g,{'bottom_text':'ground'}),
             (e,{'right_text':'excited'}),
             (r,{'top_text':'rydberg'}))
    edges = ((g,e, {'label':'$\\Omega_p$', 'lw':2}),
             (e,r, {'label':'$\\Omega_c$','lw':3, 'arrowsize':0.2}))
    graph = nx.DiGraph()
    graph.add_nodes_from(nodes)
    graph.add_edges_from(edges)

.. code:: ipython3

    d = ld.LD(graph)
    d.draw()
    d.fig.savefig('intermediate_example.png', bbox_inches='tight', dpi=150)



.. image:: output_13_0.png


More detailed examples of element configuration and diagram creation,
including embedding a diagram in a larger figure, are shown in the
Example Notebooks.

.. code:: ipython3

    ld.about()


.. parsed-literal::

    
            leveldiagram
        ====================
        
    leveldiagram Version: 0.3.2.dev1
    
            Dependencies
        ====================
        
    Python Version:       3.10.13
    NumPy Version:        1.26.0
    Matplotlib Version:   3.7.2
    NetworkX Version:     3.1