added a design principle about the reponsability of the package, and the
extension files. starting a refactoring in plot and fft
started refactoring plots away from the signal processing. put
everything in place at ContinuousData
moved plots file to be under extensions
now plt_extension.plot_with_labels doesn't know what units are. good.
about to add domain_description, values_description to ContinuousData
added properties for describing the domain and values in signals
changed the interface of ContinuousData.plot according to the new
properties
implemended the fucntions for plotting with the new properties and
interface, not tested yet
added a design issue, added few util methods
arranged the pint_extension file and it's tests
added tests for pint extensions for plots
pint_extensions functions for plots works well
creating visual tests for the plt_extension
checked that plt_extension.plot_with_labels works well
better rename inserted to README
implemented tests for the new properties of ContinuousData
implemented __str__ for segments
the tests for ContinuousData with the new properties worked! horray!