httk.atomistic.numeric_cell
===========================

.. py:module:: httk.atomistic.numeric_cell

.. autoapi-nested-parse::

   The NumericCell presentation: a Cell exposed as plain numpy numbers.



Classes
-------

.. autoapisummary::

   httk.atomistic.numeric_cell.NumericCell


Module Contents
---------------

.. py:class:: NumericCell(cell: httk.atomistic.cell_like.CellLike)

   A plain-numpy presentation of a :class:`~httk.atomistic.Cell`.

   Where a ``Cell`` holds its geometry **exactly** (a :class:`~httk.core.SurdVector` basis, exact
   ``SurdScalar`` lengths/volume, exact ``Fraction`` angles), a ``NumericCell`` mirrors that
   interface but returns plain numpy numbers — a ``float64`` :class:`numpy.ndarray` for every vector
   and a plain :class:`float` for every scalar — for callers who do not need exact arithmetic and
   just want numpy arrays.

   The presentation is numpy-backed, so constructing a ``NumericCell`` **requires numpy** (the
   ``httk-atomistic[numpy]`` extra) and raises :class:`ImportError` eagerly when it is unavailable.
   The exact object is always one hop away via :attr:`exact`.


   .. py:property:: scale
      :type: float


      The overall length factor as a plain ``float``.


   .. py:property:: unscaled_basis
      :type: httk.core.NumericVector


      The 3x3 cell vectors before applying ``scale`` as a ``float64`` numpy array.


   .. py:property:: basis
      :type: httk.core.NumericVector


      The 3x3 lattice vectors ``scale * unscaled_basis`` as a ``float64`` numpy array.


   .. py:property:: lengths
      :type: httk.core.NumericVector


      The three cell-vector lengths as a ``(3,)`` ``float64`` numpy array.


   .. py:property:: angles
      :type: httk.core.NumericVector


      The cell angles ``(alpha, beta, gamma)`` in degrees as a ``(3,)`` ``float64`` numpy array.


   .. py:property:: volume
      :type: float


      The cell volume as a plain ``float``.


   .. py:method:: metric() -> httk.core.NumericVector

      The Gram matrix ``basis * basis^T`` as a ``float64`` numpy array.



   .. py:property:: exact
      :type: httk.atomistic.cell.Cell


      The exact :class:`~httk.atomistic.Cell` this presentation wraps.