Introduction to Madagascar

What is in Madagascar?

The package consists of

1. A collection of main programs. Most programs act as filters on input data and can be chained in a Unix pipeline. For example:

   < data.rsf sfwindow n1=100 | sfbandpass fhi=60 > data2.rsf
   

   This approach follows the Unix philosophy, as formulated by Doug McIlroy, the inventor of Unix pipes (Salus, 1994):
   1. Write programs that do one thing and do it well.
   2. Write programs to work together.
   3. Write programs to handle text streams, because that is a universal interface.

   Running a command (such as sfwindow) without parameters or the necessary input and output files shows a brief documentation, explaining the program purpose and parameters. Alternatively, brief documentation is provided by sfdoc program. Main program documentation in HTML format is available on the web at http://www.reproducibility.org/RSF/.

   Madagascar uses Regularly Sampled Format (RSF) for data files, which is similar to the format used in the SEPlib library developed at the Stanford Exploration Project (SEP). The file format describes regularly sampled hypercubes. Up to 9 dimensions are supported. In accordance with the Unix philosophy, each RSF file (such as data.rsf) is a simple readable text. It contains a pointer (in= parameter) to the location of the binary data.

   Madagascar provides programs for conversion to and from other formats such as SEG-Y and SU. Madagascar currently adopts Vplot file format, also developed at SEP, for generated graphics files.

2. An API (application programmer's interface) for programmers writing their own software to manipulate RSF files. The main software language of the Madagascar package is C. Interfaces to other languages (C++, Fortran-77, Fortran-90, Python, Matlab) are also provided.

3. A project management system. The system uses and extends SCons, an open-source software construction package, to document and maintain data processing flows. Documented projects become computational recipes that can be easily exchanged among Madagascar users.

4. A collection of reproducible documents, organized in living books. Each reproducible book contains a collection of Madagascar recipes (SConstruct files) used to generate book figures. The recipes cover a variety of data processing and imaging tasks described in the books. Figures and recipes serve dual purpose with respect to Madagascar maintenance. They provide demos for introducing new users to the functionality of the package and, at the same time, regression tests for assuring the system stability under change.

Follow the links at the end of this paper for additional documentation.

Introduction to Madagascar