This repository contains modules to read and process data file(s).
It provides the vaplac package for data analysis, which heavily relies on the xpint module, implementing a subclass of UnitRegistry from the pint package, to manage units and plot labelling.

The vaplac package

This packages provides three main functionalities:

1. Validate data from a file, based on several checks contained in the vaplac.sauroneye module.
2. Plot and visualize the data.
3. Acquire the data in the form of xpint Quantity objects.

The front-end classes, methods and functions are organized as follow:

vaplac/
├── DataTaker class (base.py)
|   ├── validate method
|   ├── plot method
|   └── get method
├── plot function (_plot.py)
└── plot_files function (_plot_files.py)

The DataTaker class

DataTaker objects are instantiated by providing a data file. They can be used as shown by the following example:

1. Create a DataTaker, and validate the data

import vaplac as vpa
dtk = vpa.DataTaker()  # No file name provided: a dialog box should ask for it.
dtk.validate()  # If warnings are given, use show_data=True to display the relevant quantitites.

2. Plot the return and supply temperatures, the frequency in rpm and the inlet and outlet pressures in MPa.

dtk.plot('(Tr Ts) f/rpm (pin pout)/MPa')

3. Extract the condenser heat output, the indoor fan power and the total consumed power to compute the COP, then display some statistical characteristics.

Qcond, Pfan_in, Ptot = dtk.get('Qcond Pfan_in Ptot')
COP = (Qcond + Pfan_in) / Ptot
COP.info()

Note that the variables have the same name than the arguments of the DataTaker.get method because it improves clarity, but they do not have to. Moreover, the variables Qcond and Pfan_in can be added because they have the same dimensionality, but the operation COP + Ptot will raise a DimensionalityError.
In order to be able to display quantities such as the condenser capacity, the DataTaker class has methods to perform thermodynamic calculations, but they are not part of the user interface since the relevant quantities can be directly accessed through the DataTaker.get method.

More detailed information about each method is available with the help function.

The plot function

The top-level plot function works in the same way as the DataTaker.plot method, but is dedicated to plotting Quantity objects. Following the previous example, the condenser capacity and the total power can be plotted along with the COP using

vpa.plot([Qcond, Ptot], COP)

The plot_files function

Sometimes plotting a quantity for several files may come in handy, this can be performed using the plot_files function. Providing no parameters will open a dialog box where several files can be opened. To plot a quantity from all files in the default directory, simply use the option paths='all'.

The xpint module

xpint (extended pint) provides an extension of pint's UnitRegistry class that is used to define a new Quantity class, in order to provide a few more attributes. More details and examples can be found in the documentation, available using

import xpint
help(xpint.UnitRegistry().Quantity)