Hydra Implementation and Software

The Foundation of the Hydra Implementation

With our implementation goals in mind, current Hydra development efforts are being carried out starting with the foundation of ISIS and S-Lang:

ISIS

The ISIS system, which uses the S-Lang interpreter, is currently contributing to Hydra with: a flexible fitting engine, general line-plotting capabilities via PGPLOT, interfaces to the XSPEC models library, access to the APEC/APED X-ray emission database, FITS I/O via CFITSIO, etc.

S-Lang

This interactive programming environment/language provides the overall glue for Hydra. See the S-Lang documentation for the basics of the language.

S-Lang Modules

A large and growing list of S-Lang modules are available to provide additional functionality.

This ISIS/S-Lang foundation may be augmented by additional S-Lang modules from the many available (link above); in particular the SLIRP code generator allows a user's own C, C++, or Fortran function libraries to be directly callable from S-Lang.

Note that the [x]jed editor is very useful for the ISIS/S-Lang user: providing color-coding of syntax elements, auto-indentation, etc.

Examples of Hydra Software

S-Lang PVM Module , and an example application Using the PVM module to do distributed computation of single-parameter confidence limits.
Coming soon: PModel ... .
Event-2D Package for X-ray Event Analysis The many heads of Hydra are combined in the Event-2D X-ray analysis package.
Volumetric 3D Modeling - ``v3d'' Volume modeling library which can be generally applied, e.g., for MARX input and isis modeling.
Line-of-sight Emissivity - ``los'' Simple example of using los_integral (a routine in an MIT-internal los module.)