CVS info   : $Header$

Cactus Code Thorn Norms
Thorn Author(s)     : Frank Herrmann <herrmann@aei.mpg.de>
                    : Erik Schnetter <schnetter@aei.mpg.de>
Thorn Maintainer(s) : Frank Herrmann <herrmann@aei.mpg.de>
                    : Erik Schnetter <schnetter@aei.mpg.de>
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Purpose of the thorn:

Compute norms of the state vector, e.g. for Mexico tests.  These are
special norms that make a difference between variables which have a
second derivative taken and variables which have not; see
gr-qc/0503056.  These norms include the gradients of those variables
that have a second derivative taken.  In doing so, they take all
wavelenghts into account -- in contrast, a norm that would be based
simply on using centered differences to calculate gradients would not.



References:

Gioel Calabrese, Ian Hinder, Sascha Husa: Numerical stability for
finite difference approximations of Einstein's equations,
gr-qc/0503056 (2005)