usage.txt -- Basic operating instructions for snim pipe

DESCRIPTION:

This is a program that performs gravitational lensing simulations by executing
a series of modules.  Each module is responsible for performing one small part
of creating the data and performing the lensing calculations.  Several modules
must be run to perform a full simulation.

Modules communicate data to each other using a data stream.  At the beginning
of its operation, a module reads in the data it needs from the stream.  When
it is finished, it writes the data is wants to share back to the stream.

Special modules may perform operations not directly related to the simulation.
For instance, a module may control the number of times the simulation runs.
Another module may write data to a file or to the screen.

The simulation also provides a number of models for simulation objects such as
galaxies or the background shear.  A model can be defined once, and then used
in many places.  For example, the user might define a galaxy model based on a
gaussian, and then have several modules operate using that model.

QUICKSTART:

1) Install GSL  (from http://www.gnu.org/software/gsl/gsl.html)
2) cd snim/pipe
3) make
4) cd bin
5) emacs testest &
6) ./driver testest

CONTROL:

The simulation is controlled through the use of a script file.  This file
contains an order list of all modules that will run.  It also lists the
user-defined models (these can occur in no particular order).  White space
is generally ignored.  Comments are signified with a '#' character.

The structure of the file is as follows:

Square-Brackets name a module to run.  For example,
  [MakeGalSet]
means "Run the module with the Name MakeGalSet".  Modules are run in
the order they appear in the script.

Following the square-bracketed module name, paramters are listed along with
their value (or nothing if the parameter requires no specified value.  For
example,
  Gamma1 .01
  Gamma2 .02
Specifies that the parameters Gamma1 will be .01 and Gamma2 will be .02 for
the last listed module.

Curly-Brackets specify a model.  For example,
  {Gal}
means that you are now specifying a new galaxy model.  Since models are
referenced by their tag, they need not appear in any particular order.

Following the curly-brackets, the following parameters MUST APPEAR:
  Tag <string>
  Model <string>
where the "<string>"s have been replaced with the appropriate tag and model
names.

After these parameters, the remaining parameters are sent to the model.  For
example,
  Sigma 3.0
  Magnitude 80.0
would set the Sigma and Magnitude parameters to the given values for the last
specified model.

More information about the available modules and models are in the files:
  algo.txt     Listing of modules
  models.txt   Listing of models

See the various "test____" scripts in the snim/pipe/bin directory for examples.

RUNNING:

Pass the script name to the 'driver' binary.  For example,
  ./driver testshear
executes the script in the file "testshear".