Universal Linear Algebra API based on M4

Michael Fiero

Isaac Asiamah

Presentation Overview

• APIs• M4• Linear Algebra• Project Purpose• User Analysis• Feasability Study• Project Content• How It Works• Documentation• Conclusion

APIs

• API – Application Programming Interface• Collection of Functions and Data Structures• “Black Box”• This project is an open API

M4

• Macro Processing Language• Common Uses:

– Text Replacement Tool– As a Preprocessor– Generation of Higher Level Language Code

M4 Macros

• Macros may be either built-in or user defined• Some built in macros:

– define, undefine – defines or undefines a macro name– pushdef, popdef – similar, but use stack– changequote, changecom – change default quotes

and comments– incr, decr – increment and decrement an integer– eval – evaluates an argument as an arithmetic

expression

Defining Macros

• A macro has the form:– define (name,[expansion])

• Calling the macro requires only the name of the macro as it was defined.

• Example: define (`foo’,`Hello World!’)

=>

foo

=> Hello World!

Invoking M4

• M4 is by default included in most UNIX development environments.

• Terminal command line:– m4 [option…][file…]

• Examples of Commands:– --help, --version, --interactive

Files and M4

• M4 can take files as input– m4 myfile.m4

• Can also generate files– m4 myfile.m4 > myoutput.txt

• This is how this particular project generates APIs– m4 pyapi.m4 > linear.py

Linear Algebra

• The study of:– Vectors– Vector Spaces– Linear Transformations– Systems of Linear Equations

• Uses in Computer Science :– Graphics– Modern Math Analysis– Economics

Project Purpose

• Linear is very useful in computer science• APIs tend to be language specific• This API can be set up for use with:

– C– C++– Java– Perl– Python

User Needs

• A universal API that performs linear algebra operations and is based on M4

• Adequate documentation for using and adding functions

• M4 based test suite

Feasibility Study

• Challenges:– Becoming well acquainted with:

• M4• Perl• Python

– Creating a working API with a clear and logical structure

Feasibility Study

• There are currently Linear Algebra APIs in existence.

• However, they are language specific• The most common ones seem to be written for

Java• There are also some written for C, C++, and Perl

Included Functionality

• The final project includes an m4 API for all of the target languages.

• There is a simple setup script which will be easy to use

• It also includes a detailed documentation for how to use the functions.

• A test suite has been provided as well.

Some Included Functions

• Some of the functions included are:– Vector Normalization– Dot Product– Matrix Multiplication– Transpose of a Matrix– Square and Symmetrical Matrices– Determinant of a Matrix

How It Works

• The program contains:– M4 code for the generation of files which can be

included in your program• C and C++ - #include <linear.h>• Java – import linear.*;• Python – import linear• Perl – require “linear.pl”;

– Setup script written in bash,which calls M4 for the user to generate the necessary file

Using the Functions

• Using the functions is a matter of simply calling them based on the syntax of the language being written– C, C++, Java - function(arg1,arg2);– Python - linear.function(arg1,arg2)– Perl – function(arg1,arg2);

• Very simple, and familiar use

Adding Functions

• Adding functions requires knowledge of M4 and of each specific language

• All of the languages are similar, so adding functions is very easy

• This API is open, so it is free for anyone to add their own functions

Included Documentation

• The documentation includes:– User’s setup guide– Function documentation

• Similar to Sun’s Java Documentation – Guide to adding files– Reference Guide

Conclusion

• A good start to creating:– Universal API for C family languages

• Comprehensive linear algebra functions• Clear documentation• Ability to add functions

Questions

• This slide is here to allow for time allotted to answering possible questions.

References

• http://www.gnu.org/software/m4/• http://www.comp.leeds.ac.uk/Perl/start.html• http://docs.python.org/tut/• http://www.bernstein-plussons.com/.dowling/POCSF06/Project2.htm

l• http://en.wikipedia.org/