Work In Progress Reports

Session Chair: Robin Friedrich

The Python Matrix Object (Jim Hugunin)

Extending Python for numerical calculations
based on Jim Fulton's original implementation of a matrix object as a container type
Why yet another numeric language?
- all the numeric languages are trying to become real programming languages
Death to little languages
- Learning curve goes away - instead of 5 or 6 little languages, just learn python
- Power
- Flexibility - my numerical language can run a web browser!
What is a numeric language
- multi-dimentional arrays of numbers
  - arbitrary number of dimentions
  - all basic C types plus complex floats and doubles
  - arrays of python objects as well
  - easily extensible with new types
- efficient simple numeric operations
  - All basic operators
  - trigonometric functions
  - basic operations on large arrays are fast
  - squaring a 1000 element array...
```
  LANGUAGE			MFLOPS w/ doubles
python w/ for loop			0.01
python w/ matrix of PyObjects		0.1
Octave 1.2				0.2
gcc 2.7.0 w/ -g				1.0
MAtlab (tm) 4.2				1.5
python w/ matrix of raw numbers		1.5
python w/ raw matrix and tricks		2.6
gcc 2.6 w/ -O4				2.6
gcc 2.7 w/ -O4				6.8
         
```
- more complicated array operations
  - general purpose reduce
  - accumulate as well
  - yorick style pseudo indices
- powerful indexing
  - can get at any subarray of a matrix
  - indexing returns a new array by reference
  - strides are used to represent abritrary transposes
  - take method will select a aribitrary set of indices
- large numeric libraries
  - basic structure is equivalent to both C and FORTRAN style arrays
  - can interface to existing numerical libraries
- visualization tools
  - Tom Schwaller's pimodule - interface to plplot library
  - Tom's also working on an OpenGL module
Why Python?
- New Python object types in C!
- Python is a great language!!
- Wouldn't it be nice to write a fluid dynamics package entirely in python that can calulate the windspeed velocity of a european swallow? :-)
Major open questions
- Matrix multiplication
- Numeric exceptions/overflows
- Boolian operations - why can I implement an __add__ method, but not a __lessThan__ method?
- Guido: Notion does not extend to: A __lessThan__ B __lessThan__ C ?
- By reference vs. By Copy - To protect newbe programmers?

created working matrix object
Konrad Hinsen's complex numbers
two modules based on prototype matrix object available

several small patches to the python grammer being tested... (and seeking blessings from Guido)

  a**b == pow(a,b)             # guido's blessed
  a[1,2,3] == a[(1,2,3)]       # guido's blessed
  1+2j == complex(1,2)	       # not blessed yet
  a[1:3, :4,6] == a[slice(1,3), slice(None, 4), 6] # not blessed yet
  a[1:3, 2:4]  # multidimentional slices in general
  a[.., 3]     # variable number of slices before comma
  a[3, .., 4]  # variable number of slices inbetween 0: and :-1

Python is great!

Python Free-for-all

Q: Are we worryed about too much success?
A: No, roughly half of the audience would be ready to sell their services as python consultants
To many users to fast is a great danger because it forces you to make quick decisions that might not be the best ones
We're not prepared to support the people without a clue
Would be nice to make the locator service for consultants a reality
Q: Is there going to be a CD with python and examples included in Mark Lutz's python book?
A: Maybe, The word is O'Reily has not decided yet
The list of python.org URL's should appear in Mark Lutz's book
Q: How about a phone number for the PSA?
A: Who's going to answer it?
Guido: If the questions come in too fast or get asked over and over then I look for a technical solution (e.g. a better install program) This is why I want to grow, but not too fast
A a killer app helps the growth of the language since people would then download python to run the killer app, and then they would maybe experiment with it later because they already have it
example killer apps: make, MajorDomo, HyperMail
Q: Do we need a registry Grail app that would allow folks to volunteer and track Grail enhancements and bug fixes
A: we don't have a problem managing too many people volunteering We need to people *to* volunteer
Problem: all the database interfaces are slightly different
Q: Do we need a SIG for generalizing database access (e.g. to persue a Stanford/Scott Hassan InfoBus model)?
A: Yes!
The NeXT Enterprise Object Framework model is a nice product to maybe emulate
Roger: I like the Modeler classes part of EOF but not some of the restrictions of how EOF really works best with SQL databases with non-duplicate keys. We need a more generalized mechanism (like InfoBus which abstracts away from the relational model more)
Q: Is it reasonable to charge for it since you have to pay for database s/w anyway most of the time?
A: Don't charge for the top level framework (e.g. InfoBus) but do charge for certain adaptors (e.g. for sybase)
Paul Everitt will champion the database SIG (or at least find a champion? John Viega?), not for generlized persistance, rather generized database access across platforms
Guido: I can think of many ways to make pickle faster, but so far no-one has pushed me on speeding it up
Are packages a way of speeding up downloads of large collections of modules (e.g. Scott Hassans chat room applet)
Yes, maybe, most of the slowdown is http requests and parsing