.. _python-plotting:

Python Plotting
===============

The simplest and most straight forward use case is the generation of plots 
with default isolines and spacing. Here is a brief example to demonstrate 
how to create a pressure-enthalpy (:math:`\log p,h`) plot for propane 
(R-290) with automatic isoline spacing:

.. plot::
    :include-source:

    import CoolProp
    from CoolProp.Plots import PropertyPlot
    plot = PropertyPlot('R290', 'ph')
    plot.calc_isolines()
    plot.show()

The following example can be used to create a temperature-entropy (:math:`T,s`) plot for
propane (R290) with isolines for the vapour quality in steps of 0.2:

.. plot::
    :include-source:

    import CoolProp
    from CoolProp.Plots import PropertyPlot
    ts_plot = PropertyPlot('R290', 'Ts', tp_limits='ORC')
    ts_plot.calc_isolines(CoolProp.iQ, num=6)
    ts_plot.show()

The following example can be used to create a pressure-enthalpy (:math:`\log p,h`) plot for 
R-134a with a couple of isotherms and isentropic lines:

.. plot::
    :include-source:
  
    import CoolProp
    from CoolProp.Plots import PropertyPlot
    plot = PropertyPlot('HEOS::R134a', 'PH', unit_system='EUR', tp_limits='ACHP')
    plot.calc_isolines(CoolProp.iQ, num=11)
    plot.calc_isolines(CoolProp.iT, num=25)
    plot.calc_isolines(CoolProp.iSmass, num=15)
    plot.show()

Here is an example for R-245fa using two different ways to generate the isobars:
    
.. plot::
    :include-source:
    
    import CoolProp
    from CoolProp.Plots import PropertyPlot
    plot = PropertyPlot('HEOS::R245fa', 'TS', unit_system='EUR', tp_limits='ORC')
    plot.calc_isolines(CoolProp.iQ, num=11)
    plot.calc_isolines(CoolProp.iP, iso_range=[1,50], num=10, rounding=True)
    plot.draw()
    plot.isolines.clear()
    plot.props[CoolProp.iP]['color'] = 'green'
    plot.props[CoolProp.iP]['lw'] = '0.5'
    plot.calc_isolines(CoolProp.iP, iso_range=[1,50], num=10, rounding=False)
    plot.show()
    
The available plots are listed in the :py:class:`CoolProp.Plots.Common.Base2DObject`  
and at this time (May 2016) this list contains (:math:`T,s`), (:math:`p,h`), 
(:math:`h,s`), (:math:`p,s`), (:math:`p,\rho`), (:math:`T,\rho`), (:math:`p,T`) and 
(:math:`p,u`) plots. 

Some of the commonly used `Matplotlib <http://www.matplotlib.org>`_ functions,
such as :func:`title`, :func:`grid`, :func:`xlabel` and :func:`ylabel` have been wrapped in
the :py:class:`CoolProp.Plots.Common.BasePlot` class to make the plotting of
graphs a little simpler, for example:

.. plot::
    :include-source:

    import CoolProp 
    from CoolProp.Plots import PropertyPlot
    ts_plot = PropertyPlot('Water', 'Ts')
    ts_plot.calc_isolines(CoolProp.iQ, num=11)
    ts_plot.title(r'$T,s$ Graph for Water')
    ts_plot.xlabel(r'$s$ [kJ/kg K]')
    ts_plot.ylabel(r'$T$ [K]')
    ts_plot.grid()
    ts_plot.show()
    

Mixture Syntax
==============

You can also specify mixtures straight away and pass the mole fractions as part of the 
fluid string. 
    
.. plot::
    :include-source:   

    from CoolProp.Plots import PropertyPlot
    plot = PropertyPlot("REFPROP::ISOBUTAN[0.8]&PROPANE[0.2]", 'PH', unit_system='EUR', tp_limits='ACHP')
    plot.calc_isolines()
    plot.show()
    
If you would like to specify the mass fractions instead, you have to construct the state
object separately and pass it to the plot object instead of a string.
    
.. plot::
    :include-source:   

    import CoolProp
    state = CoolProp.AbstractState("REFPROP", "ISOBUTAN&PROPANE")
    state.set_mass_fractions([0.8,0.2])
    from CoolProp.Plots import PropertyPlot
    plot = PropertyPlot(state, 'TS', unit_system='EUR', tp_limits='ACHP')
    plot.calc_isolines()
    plot.show()


