NormalMode.hpp

Go to the documentation of this file.

/**
 * @file
 * Declares functionality in the `OpenMPCD::NormalMode` namespace.
 */
 
#ifndef OPENMPCD_NORMALMODE_HPP
#define OPENMPCD_NORMALMODE_HPP
 
#include <OpenMPCD/Vector3D.hpp>
 
namespace OpenMPCD
{
 
/**
 * Namespace for functionality related to normal modes.
 *
 * Given a number \f$ N \f$ of coordinate vectors \f$ \vec{r}_n \f$,
 * \f$ n \in \left[ 1, N \right] \f$,
 * the \f$ i \f$-th normal coordinate \f$ \vec{q}_i \f$, with
 * \f$ i \in \left[ 0, N \right] \f$, is defined as
 * \f[
 *      \vec{q}_i
 *      =
 *      \frac{1}{N} \sum_{n=1}^N
 *      \cos\left( \frac{ i \pi \left( n + S \right) }{N} \right) \vec{r}_n
 * \f]
 * where \f$ S \f$ is a shift parameter.
 */
namespace NormalMode
{
 
/**
 * Calculates a normal coordinate.
 *
 * @see OpenMPCD::NormalMode
 *
 * @throw OpenMPCD::NULLPointerException
 *        If `OPENMPCD_DEBUG` is defined, throws if `vectors == nullptr`.
 * @throw OpenMPCD::InvalidArgumentException
 *        If `OPENMPCD_DEBUG` is defined, throws if `N == 0`, or if `i` is out of
 *        range.
 *
 * @tparam T The underlying floating-point data type.
 *
 * @param[in] i
 *            The index of the normal coordinate to compute, which must lie in
 *            the range `[0, N]`.
 * @param[in] vectors
 *            The input vectors to use. Must be a non-`nullptr` pointer pointing
 *            to at least `N` instances.
 * @param[in] N
 *            The number of input coordinate vectors, which must not be `0`.
 * @param[in] shift
 *            The shift parameter \f$ S \f$.
 */
template<typename T>
const Vector3D<T> computeNormalCoordinate(
    const unsigned int i, const Vector3D<T>* const vectors,
    const std::size_t N, const T shift = 0);
 
} //namespace NormalMode
} //namespace OpenMPCD
 
 
#include <OpenMPCD/ImplementationDetails/NormalMode.hpp>
 
#endif //OPENMPCD_NORMALMODE_HPP