This repo contains a Cactus arrangement to interact with Sgrid
--------------------------------------------------------------

Sgrid itself is not part of Cactus. But it is publicly available at
https://github.com/sgridsource

The thorns in the Cactus arrangement here can load Sgrid initial data,
so that one can evolve them forward in time with Cactus.
Currently the arrangement contains these thorns:

DNSdata
-------
This thorn reads BNS initial data by calling functions from
inside the Sgrid library. To link the Sgrid library into Cactus you need to
use this thorn together with the thorn ExternalLibraries-SGRID found at
https://github.com/EinsteinToolkit/ExternalLibraries-SGRID
More documentation about the DNSdata thorn can found in the DNSdata
directory, e.g. in
https://github.com/wofti/CactusSgrid/blob/master/DNSdata/README


BNSdata
-------
This is an old thorn that reads BNS initial data by calling an Sgrid
executable via the standard C-function "system". For some reason, the MPI
in Cactus does not allow calls to "system" on some machines. Therefore this
thorn is deprecated.