AipyPhilosophy

AIPY Philosophy (e.g. Pedantry)

AIPY is:

• A module adding tools for interferometry to Python (not visa versa)‏
• An amalgam of pure-Python and wrappers around C++ and Fortran
• Object-Oriented
• A collection of low- to mid-level operations (you write the program)‏
• A toolkit (i.e. a grocery store, not a restaurant)‏

AIPY is not:

• A solution (it is just a tool to help you find it)‏
• A one-stop shop (it makes use of other open-source projects)‏
• A replacement for other interferometry packages
• Wedded to a file format (but only MIRIAD-UV, FITS currently supported)‏

Why Another Interferometry Package?

New Problems to Solve

• Wide fields of view
• Large relative bandwidths
• Huge numbers of antennas
• Non-tracking primary beams
• Real-time processing
• Source separation
• Ionospheric distortion

Why Python?

• Interpreted (up to 5x more productive than compiled languages, according to Burton Group study)‏
• Object-Oriented
• Readable
• Fast, high-level data types
• Large community of programmers
• Fast-growing community of numerical/scientific/astronomy programmers

Performance

• Generally, only a small fraction of code needs to run fast
• Python's profiler can tell you where the bottlenecks are
• Bottlenecks can be recoded in C/C++/ Fortran and wrapped into Python
• NumPy, the foundation of numerical/vectorized processing in Python, is coded in C and runs on average only 1.5 times slower than pure C
• You should only be allowed to worry about speed while your code is actually running

Zen of AIPY (with apologies to The Zen of Python)

• Explicit is better than implicit
• Simple is better than complex
• Complex is better than complicated
• Special cases aren't special enough to break the rules
• Practicality beats purity
• There should be one (and preferably only one) obvious way to do it, although that way may not be obvious at first unless you're Dutch
• Now is better than never
• In the face of ambiguity, refuse the temptation to guess
• Don't handicap the programmer; allow them all the rope they want
• Don't hide data; return it (or at least grant access) at every turn