3.1.0 - 2020-10-2

Added

• Helper functions pwa.pandas_to_numpy to convert Pandas data types to
  Numpy Structured Arrays, and pwa.to_contiguous to convert DataFrames
  and Structured Arrays columns to contiguous arrays for quicker
  processing and C/Fortran Support
• New experimental file format ParticleGZ, a direct-to-memory file format
  using pickle, csv, and Tar/GZ to compress data into a single archive for
  easy use.
• Reference documentation to the Read The Docs for the various modules
  in PyPWA.
• Initial examples section added.

Changed

• Users now have to option to request structured Numpy arrays or Pandas
  DataFrames from pwa.read and pwa.get_reader
• pwa.cache now defaults to intermediate caching, and has to be disabled
  for use with caching files
• Vectors str and repr field now output the mean of their theta, phi, as well
  as particle id and mass if they are available.
• Vectors now wrap individual numpy arrays instead of a single structured
  array or DataFrame. This was done to improve performance of the vector
  as well as to make it C contiguous.

Fixed

• pwa.write would fail to write CSV Numpy Arrays
• pwa.write would occasionally fail to detect DataFrames
• Vectors would occasionally replace their fields with just their x values.