Cactus Code Thorn VolumeIntegrals_vacuumX
Author(s)    : Zachariah B. Etienne
               Leonardo Werneck
               Ian Ruchlin
Note         : Thorn for integration of spacetime quantities, in
               integration volumes consisting of spherical shells,
               regions with hollowed balls, and simple spheres.

Usage example: Except for the definition of integrands, the
               behavior of this thorn is almost completely driven
               by the parameter file.

               Here's an example of a parameter file that performs
               a total of 10 integrals, computed every 64 timesteps:
               1. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume.
               2. Exactly the same as (1), but excising the region
                  inside a sphere of radius 2.2 tracking the center
                  of the *ZEROTH* AMR grid (initially at
                  (x,y,z)=(-5.9,0,0)).
               3. Exactly the same as (2), but additionally excising the region
                  inside a sphere of radius 2.2 tracking the center
                  of the *FIRST* AMR grid (initially at
                  (x,y,z)=(+5.9,0,0)).
               4. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 8.2.
               5. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 12.0
               6. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 16.0
               7. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 24.0
               8. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 48.0
               9. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 96.0
              10. Integral of Hamiltonian & momentum constraints,
                  over the entire grid volume, minus the spherical
                  region inside coordinate radius 192.0

ActiveThorns = "VolumeIntegrals_vacuumX"
VolumeIntegrals_vacuumX::NumIntegrals = 10
VolumeIntegrals_vacuumX::VolIntegral_out_every = 64
VolumeIntegrals_vacuumX::enable_file_output = 1
VolumeIntegrals_vacuumX::outVolIntegral_dir = "volume_integration"
VolumeIntegrals_vacuumX::verbose = 1
# The AMR centre will only track the first referenced integration quantities that track said centre.
#   Thus, centeroflapse output will not feed back into the AMR centre positions.
VolumeIntegrals_vacuumX::Integration_quantity_keyword[1] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[2] = "usepreviousintegrands"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[3] = "usepreviousintegrands"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[4] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[5] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[6] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[7] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[8] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[9] = "H_M_CnstraintsL2"
VolumeIntegrals_vacuumX::Integration_quantity_keyword[10]= "H_M_CnstraintsL2"

# Second integral takes the first integral integrand, then excises the region around the first BH
VolumeIntegrals_vacuumX::volintegral_sphere__center_x_initial            [2] = -5.9
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius              [2] =  2.2
VolumeIntegrals_vacuumX::volintegral_sphere__tracks__amr_centre          [2] =  0
VolumeIntegrals_vacuumX::volintegral_usepreviousintegrands_num_integrands[2] =  4

# Third integral takes the second integral integrand, then excises the region around the second BH
VolumeIntegrals_vacuumX::volintegral_sphere__center_x_initial            [3] =  5.9
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius              [3] =  2.2
VolumeIntegrals_vacuumX::volintegral_sphere__tracks__amr_centre          [3] =  1
VolumeIntegrals_vacuumX::volintegral_usepreviousintegrands_num_integrands[3] =  4

# Just an outer region
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[4] = 8.2
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[5] =12.0
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[6] =16.0
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[7] =24.0
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[8] =48.0
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[9] =96.0
VolumeIntegrals_vacuumX::volintegral_outside_sphere__radius[10]=192.0


TODO/FIXME   : This thorn currently depends on ML_BSSN. There is a bit
               of code duplication and duplicated functionality between
               VolumeIntegrals_vacuumX and VolumeIntegrals_GRMHDX, to
               ensure that VolumeIntegrals_vacuumX can be used without
               requiring a GRMHD code. For this thorn to make use of
               gridfunctions either in ML_BSSN/ADMBase *or* Hydrobase
               does not seem to be possible within the ETK at this time.


Maintainer(s): Zachariah B. Etienne
License      : BSD 2-Clause (FreeBSD license)
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