Create Observable Object
========================

Problem
-------

You want to create an :class:`~geodesic.entanglement.object.object.Observable` object and add it to the entanglement graph.


Solution
--------

An :class:`~geodesic.entanglement.object.object.Observable` object is a physical property or attribute that can be observed by an :class:`~geodesic.entanglement.object.Object.Entity` or :class:`~geodesic.entanglement.object.Object.Dataset`. :class:`~geodesic.entanglement.object.object.Observable` typically denotes something measurable by a sensor or methodology.

In this example, we are going to create a :class:`~geodesic.entanglement.object.object.Observable` object for **maximum fire radiative power** band from the  `MODIS Terra Thermal Anomalies & Fire Daily Global <https://developers.google.com/earth-engine/datasets/catalog/MODIS_061_MOD14A1#description>`_. For details on adding the *MODIS Terra Thermal Anomalies & Fire Daily Global* dataset, refer to :ref:`adding Google Earth Engine data set<from_google_earth_engine>`.

All :class:`~geodesic.entanglement.object.Object` can have additional qualifers, though ``name`` is the only qualifier that is required. In this example, we will also be adding ``domain``, ``category``, and ``type`` qualifiers, along with ``description`` and ``alias`` attributes.

Setup
~~~~~
Start by setting up the :ref:`basic geodesic<geodesic_basics>` workflow in python.

.. code-block:: python

    >>> import geodesic
    >>> geodesic.set_active_project('cookbook-examples')

Creating The Object
~~~~~~~~~~~~~~~~~~~

.. code-block:: python

    >>> observable_object = geodesic.entanglement.Object(object_class='observable',
                         name='fire-radiative-power, 
                         domain = 'earth-observation', 
                         category = 'thermal-anomalies', 
                         type='radiative-power',
                         description = 'Fire radiative power (FRP) within the pixel is estimated using the empirical relationship established in Kaufman et al. 1998 paper "Potential global fire monitoring from EOS-MODIS."',
                         alias = 'Fire radiative power'
                        )
    >>> observable_object.save()

The ``domain``, ``category``, and ``type`` qualifers are used to help organize and classify the object. The ``description`` and ``alias`` attributes are optional and can be used to store additional information about the object.

Accessing the Object
~~~~~~~~~~~~~~~~~~~~
To check that your object has been created and added to the entanglement graph, you can use the :meth:`~geodesic.entanglement.object.Object.get_objects` method to search either by object type or by name.


.. code-block:: python
    :caption: Search by object class

    >>> geodesic.get_objects(object_class='observable')
      [observable:earth-observation:thermal-anomalies:radiative-power:fire-radiative-power]

.. code-block:: python
    :caption: Search by object name

    >>> geodesic.get_objects(search='fire')
     [observable:earth-observation:thermal-anomalies:radiative-power:fire-radiative-power]

We can save the search results as a list of :class:`~geodesic.entanglement.object.Objects` and then access the object by index which will allow us to access the object's attributes.

.. code-block:: python
    :caption: Accessing the object's attributes

    >>> obj_lst = geodesic.get_objects(search='fire')
    >>> fire_radiative_power_obj = obj_lst[0]
    >>> dict(fire_radiative_power_obj)

.. figure:: ../../_static/img/cookbooks/entanglement/observable_object_dic.png
    :width: 600