=====================
One task, four fronts
=====================


The task is CHILL+ on frame 1 of ``input/traj/mW_cubic.lammpstrj``, LAMMPS type 1.
The result is 4096 cubic sites.
``docs/tutorials/test_cross_language.py`` runs the fronts.

.. table::

    +----------+-----------------------------------------------------------------------+-------+
    | language | call                                                                  | cubic |
    +==========+=======================================================================+=======+
    | CLI      | ``seams chill-plus input/traj/mW_cubic.lammpstrj --type 1 --frame 1`` |  4096 |
    +----------+-----------------------------------------------------------------------+-------+
    | Python   | ``pydseams.read(path, atom_type=1).chill_plus().cubic``               |  4096 |
    +----------+-----------------------------------------------------------------------+-------+
    | R        | ``sum(chill_plus(read_frame(path, type=1L))$name =`` "cubic")=        |  4096 |
    +----------+-----------------------------------------------------------------------+-------+
    | Julia    | ``chill_plus(read_frame(path; type=1)).counts["cubic"]``              |  4096 |
    +----------+-----------------------------------------------------------------------+-------+

Python is ``pip install pydseamslib``.
The import is ``pydseams``.
``import pydseamslib`` is the same package.
The package name the d-SEAMS paper should use is ``pydseamslib``.
R is ``bindings/r/dseams``.
Julia is ``bindings/julia/Dseams`` and calls ``libseams_lang`` with ``ccall``.

Every front defaults to the cutoff neighbour list (``graph = "cutoff"``, pairs closer than ``cutoff``, 3.5 Å).
``graph = "mutual"`` is the mutual four-nearest list with candidates inside ``cutoff + 1.5``, under the same name on every front.
On this lattice the two lists label the same sites cubic.
On the mixed TIP4P dump (``input/traj/exampleTraj.lammpstrj``, type 2) they do not:

.. table::

    +--------+---------------------------------------------------+
    | front  | mutual-list call                                  |
    +========+===================================================+
    | CLI    | ``seams chill-plus FILE --type 2 --graph mutual`` |
    +--------+---------------------------------------------------+
    | Python | ``frame.chill_plus(graph``"mutual")=              |
    +--------+---------------------------------------------------+
    | R      | ``chill_plus(frame, graph = "mutual")``           |
    +--------+---------------------------------------------------+
    | Julia  | ``chill_plus(frame; graph = "mutual")``           |
    +--------+---------------------------------------------------+

The cutoff list gives 12 interClathrate and 238 water.
The mutual list gives 1 clathrate, 7 interClathrate, and 242 water.

A cage signature takes the same face-edge window on every front.
The default is ``2.65,3.15`` in the coordinate units of the file.
``none`` leaves the cage bound to the face census.

.. table::

    +--------+--------------------------------------------------------------------------------------------+
    | front  | call                                                                                       |
    +========+============================================================================================+
    | CLI    | ``seams cages FILE --signature 512 --cage-edge none``                                      |
    +--------+--------------------------------------------------------------------------------------------+
    | Python | ``frame.cages_by_signature("512", edge``"none")=                                           |
    +--------+--------------------------------------------------------------------------------------------+
    | Lua    | ``dseams.cages_by_signature(frame, "512", {edge = "none"})``                               |
    +--------+--------------------------------------------------------------------------------------------+
    | C      | ``seams_frame_signature_edge(frame, 3.5, 1, "cutoff", "512", "none", &n_cages, &n_atoms)`` |
    +--------+--------------------------------------------------------------------------------------------+

A null C edge string keeps the default.
Set the window to the heavy-atom contact range of the model.
Widen it for a compressed cell or a guest that stretches a cage.
A nanometre file uses ``0.265,0.315``.

``tests/chill_plus_fronts.py`` (Meson test ``chill_plus_fronts_agree``) runs all four fronts on that dump with both lists.
It checks the histograms on all four and the per-atom labels on Python, R, and Julia.
The Python front needs a pydseamslib whose ``chill_plus`` takes ``graph``.