*****
Input
*****

All the input required to run an EBM with this source code is provided by a **configuration.ini** file which you have to create. 
As already mentioned in the section :doc:`How to use <howtouse>`:

.. Important::

   The configuration.ini file will provide the physical sense of the EBM!

Here shown is, how this file is structured and which syntax has to be maintained to make it readable to the ``importer`` function.

There are four main components of the file, the modelequation parameters ``eqparam``, the runge-kutta parameters ``rk4input``, the initial condition parameters ``initials`` and a compilation of physical functions with their specific parameters ``funccomp``.

If you want to put together a new model simply create a textfile with the suffix **.ini**. These four main components will be used as header of a section, whereas the headers the ``funccomp`` has to be replaced by ``func0``, ``func1``,... depending on how many functions you want to include. It will look like this::

    [eqparam]

    [rk4input]
    
    [initials]

    [func1]
    
    [func2]
    .
    .
    [func_]

Now each section has to be filled with parameters. ``eqparam``, ``rk4input`` and ``initials`` always contain the same parameters since they define **how** the algorithm runs. The func-sections have to be modified since they define **which** model equation the algorithm solves. 

.. Note::

   The order of your sections doesn't matter as long as the headers are correctly labeled.

The parameters of the sections look like this (which is the configuration of the 0D-EBM given as demo)::

    [eqparam]
    C_ao=70*4.2e6

    [rk4input]
    number_of_integration=365*10
    stepsize_of_integration=60*60*24
    spatial_resolution=0
    both_hemispheres=True
    latitudinal_circle=True
    latitudinal_belt=False

    eq_condition=False
    eq_condition_length=100
    eq_condition_amplitude=1e-3

    data_readout=1
    number_of_externals=0

    [initials]
    time=0
    zmt=273+17
    gmt=273+17
    latitude_c=0
    latitude_b=0
    initial_temperature_cosine=True
    initial_temperature_amplitude=30
    initial_temperature_noise=True
    initial_temperature_noise_amplitude=5

If the meaning of parameters is unclear, there is a detailed definition of the parameters given in the attached Readme.txt.

If you now want to add functions you can write them into the configfile with the scheme shown above. If we want to add two functions, one for incoming radiative energy flux and one for outgoing radiative energy flux, this might look like this::

    [func0]
    func=R_ininsolalbedo
    Q=342
    m=1
    dQ=0

    albedo=Albedo0D 
    albedoread=True           
    albedoparam=[0.3] 

    noise=False
    noiseamp=342*0.03
    noisedelay=1
    seed=True
    seedmanipulation=0

    sinusodial=False
    convfactor=1
    timeunit='annualmean'
    orbital=False   
    orbitalyear=0

    [func1]
    func=R_outplanck
    grey=0.612
    sigma=const.sigma

.. Important::
    
   To define which function you add, insert the name at *func=*, then add the parameters below.

A detailed description of the function parameters is given along with the implementation of the :doc:`Functions <code/functions>`.

With this content the **0DEBM_Config.ini** is complete and the OD-EBM can be run the way it is described in :doc:`How to use <howtouse>`.