----------------------------------------------
Setting the mapper with output concentrations
----------------------------------------------

.. currentmodule:: pycif.plugins.models.template

Here, we propose to extract output concentrations from pre-computed output files.
This is possible in the template by using the option ``only_outputs`` in the model
paragraph.

.. literalinclude:: ../yml/4_onlyconcs.yml
    :linenos:
    :language: yaml

Compared to the previous yaml, the following elements have been added:

1. ``mode`` paragraph: this is the :doc:`execution mode </documentation/plugins/modes/index>`.
   It is needed for pyCIF to go further than the initialization step. Here we are
   computing a forward simulation to compare simulations with observations

2. ``chemistry`` paragraph: this paragraph indicates information about species
   to be transported and/or emitted in the model

3. ``datavect`` paragraph: this paragraph indicated all required information about
   pyCIF inputs. Further details is given :doc:`here </documentation/plugins/datavects/standard>`

In the example above, observations are generated at random locations.
If one needs/wants to use a file of its own making, please refer to the dedicated documentation
page about observation inputs (:doc:`here </documentation/input-outputs/monitor>`)
to properly prepare the file.

Once successfully running, the forward working files are saved in the folder
``$runsubdir/obsoperator/fwd_0000/``. In particular, the output simulations
and corresponding observations are saved here: ``$runsubdir/obsoperator/fwd_0000/obsvect``.