.. index:: pair: class; rgpot::CalcResult
.. _doxid-classrgpot_1_1_calc_result:

class rgpot::CalcResult
=======================

.. toctree::
	:hidden:

Overview
~~~~~~~~

Owns the force DLPack tensor and stores energy/variance from a calculation. :ref:`More...<details-classrgpot_1_1_calc_result>`


.. ref-code-block:: cpp
	:class: doxyrest-overview-code-block

	#include <types.hpp>
	
	class CalcResult {
	public:
		// construction
	
		:ref:`CalcResult<doxid-classrgpot_1_1_calc_result_1a5b4ea0153b7f2c45fb42852fabf674e5>`();
		:target:`CalcResult<doxid-classrgpot_1_1_calc_result_1a8207f2864a461f1fcbfbcc1b3fac3a4a>`(CalcResult&& other);
		:target:`CalcResult<doxid-classrgpot_1_1_calc_result_1ad4019d593c812ca9045b4d1f027b9d58>`(const CalcResult&);
		:target:`~CalcResult<doxid-classrgpot_1_1_calc_result_1aeb9cca3287cb6ad1727a1b1df282fbc8>`();

		// methods
	
		CalcResult& :target:`operator=<doxid-classrgpot_1_1_calc_result_1ac8d7f1237bcb60541be6472dc69c504d>`(CalcResult&& other);
		CalcResult& :target:`operator=<doxid-classrgpot_1_1_calc_result_1a0270e8895242932d6e844e17b0f0593e>`(const CalcResult&);
		rgpot_force_out_t& :ref:`c_struct<doxid-classrgpot_1_1_calc_result_1ae35ee903ca10d45a9e385327e8a79762>`();
		double :ref:`energy<doxid-classrgpot_1_1_calc_result_1afc8a2b34da93fdaa39b36a22558a8736>`() const;
		double :ref:`variance<doxid-classrgpot_1_1_calc_result_1acc76ed425c76d1fc79803f6f88a36594>`() const;
		const double* :ref:`forces_data<doxid-classrgpot_1_1_calc_result_1a8252035b160b3fd53026fdd7f06245bb>`(size_t& n_elements) const;
		std::vector<double> :ref:`forces_vec<doxid-classrgpot_1_1_calc_result_1a97f568661a4d4df34f28e2940ca94a27>`() const;
		bool :ref:`has_forces<doxid-classrgpot_1_1_calc_result_1a51827c449733aa348ff404b24e5662a0>`() const;
	};
.. _details-classrgpot_1_1_calc_result:

Detailed Documentation
~~~~~~~~~~~~~~~~~~~~~~

Owns the force DLPack tensor and stores energy/variance from a calculation.

Wraps ``rgpot_force_out_t``. The ``forces`` field starts as ``NULL`` and is set by the potential callback to an owning DLPack tensor. The destructor calls ``rgpot_tensor_free()`` to release the forces tensor.

For CPU tensors, use ``:ref:`forces_data() <doxid-classrgpot_1_1_calc_result_1a8252035b160b3fd53026fdd7f06245bb>``` to access the raw pointer or ``:ref:`forces_vec() <doxid-classrgpot_1_1_calc_result_1a97f568661a4d4df34f28e2940ca94a27>``` to copy forces into a ``std::vector<double>``.

Construction
------------

.. index:: pair: function; CalcResult
.. _doxid-classrgpot_1_1_calc_result_1a5b4ea0153b7f2c45fb42852fabf674e5:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	CalcResult()

Create a zeroed result buffer for a calculation.

Methods
-------

.. index:: pair: function; c_struct
.. _doxid-classrgpot_1_1_calc_result_1ae35ee903ca10d45a9e385327e8a79762:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	rgpot_force_out_t& c_struct()

Access the underlying C struct (mutable).



.. rubric:: Returns:

Mutable reference; used internally by ``:ref:`PotentialHandle::calculate() <doxid-classrgpot_1_1_potential_handle_1af864dc8f487587b425fb6c3fdf3bc705>```.

.. index:: pair: function; energy
.. _doxid-classrgpot_1_1_calc_result_1afc8a2b34da93fdaa39b36a22558a8736:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	double energy() const

Returns the calculated potential energy.



.. rubric:: Returns:

Energy in the unit system of the potential.

.. index:: pair: function; variance
.. _doxid-classrgpot_1_1_calc_result_1acc76ed425c76d1fc79803f6f88a36594:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	double variance() const

Returns the variance / uncertainty estimate.



.. rubric:: Returns:

Variance (0.0 when not applicable).

.. index:: pair: function; forces_data
.. _doxid-classrgpot_1_1_calc_result_1a8252035b160b3fd53026fdd7f06245bb:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	const double* forces_data(size_t& n_elements) const

Returns a raw pointer to the forces data (CPU only).

The returned pointer is valid for the lifetime of this :ref:`CalcResult <doxid-classrgpot_1_1_calc_result>`.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- n_elements

		- Output: number of doubles in the forces array.



.. rubric:: Returns:

Raw pointer to the force data, or ``nullptr`` if no forces tensor.

.. index:: pair: function; forces_vec
.. _doxid-classrgpot_1_1_calc_result_1a97f568661a4d4df34f28e2940ca94a27:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	std::vector<double> forces_vec() const

Copy forces into a std::vector<double>.



.. rubric:: Returns:

Vector of forces [n_atoms \* 3].

.. index:: pair: function; has_forces
.. _doxid-classrgpot_1_1_calc_result_1a51827c449733aa348ff404b24e5662a0:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	bool has_forces() const

Check if forces are available.



.. rubric:: Returns:

True if the forces tensor has been set by the callback.