horizon finding utilities

For black hole simulations requiring excision, HAD comes with several parallel horizon finding utilities for dynamically moving the excision region as the horizon changes position in time.
Parameters for controlling this:
In order to use the horizon finding tools in HAD, the user needs to complete the routine grid_ahfind found in the user defined application file comp_amr_error.f. If no horizon finding capability is needed, this routine can be left blank.

Routine grid_ahfind is a project specific routine to find where to excise. This routines requires centers for up to two masks to be specified. The routine is responsible for determining on the grid whether the quantities need to be adjusted. The first index indicates which mask is being addressed, either mask #1 or mask #2. In local_left, the user specifies the x,y,z coordinates of the furthest extent of the horizon to the left (or negative direction) of the singularity on the local processor. In local_right, the user specifies the x,y,z coordinates of the furthest extent of the horizon to the right (or positive direction) of the singularity on the local processor. These are local to the processor calling grid_ahfind, and global bounds will be found in the driver level routine level_bhmask_local(). The data structures for routine grid_ahfind are found in had/include/mask.inc.

Notes

See Also

mask, comp_amr_error, List of required routines

Index of all manual pages

Examples

None