MathNumeric.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* MathNumeric.h                                               (C) 2000-2026 */
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/* Mathematical operations on numeric types (Real2, Real3, NumVector, ...)   */
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#ifndef ARCCORE_BASE_MATHNUMERIC_H
#define ARCCORE_BASE_MATHNUMERIC_H
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#include "arccore/base/NumVector.h"
#include "arccore/base/NumMatrix.h"
 
#include "arccore/base/MathReal2.h"
#include "arccore/base/MathReal3.h"
#include "arccore/base/MathReal2x2.h"
#include "arccore/base/MathReal3x3.h"
 
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namespace Arcane::math
{
 
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/*!
 * \brief Compares the vector with the vector zero.
 *
 * The matrix is nearly zero if and only if each of its components
 * is less than a given epsilon. The epsilon value used is that
 * of FloatInfo<DataType>::nearlyEpsilon():
 * \f[A=0 \Leftrightarrow |A.x|<\epsilon,|A.y|<\epsilon,|A.z|<\epsilon \f]
 */
template <typename DataType, int Size> constexpr ARCCORE_HOST_DEVICE bool
isNearlyZero(const NumVector<DataType, Size>& v)
{
  bool is_nearly_zero = true;
  for (int i = 0; i < Size; ++i)
    is_nearly_zero = is_nearly_zero && math::isNearlyZero(v[i]);
  return is_nearly_zero;
}
 
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/*!
 * \brief Compares the matrix with the zero matrix.
 *
 * The matrix is zero if and only if each of its components
 * is less than a given epsilon. The epsilon value used is that
 * of float_info<value_type>::nearlyEpsilon():
 * \f[A=0 \Leftrightarrow |A.x|<\epsilon,|A.y|<\epsilon,|A.z|<\epsilon \f]
 *
 * \retval true if the matrix is equal to the zero matrix,
 * \retval false otherwise.
 */
template <typename DataType, int RowSize, int ColumnSize> constexpr ARCCORE_HOST_DEVICE bool
isNearlyZero(const NumMatrix<DataType, RowSize, ColumnSize>& v)
{
  bool is_nearly_zero = true;
  for (int i = 0; i < RowSize; ++i)
    is_nearly_zero = is_nearly_zero && math::isNearlyZero(v.row(i));
  return is_nearly_zero;
}
 
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//! Returns the square of the L2 norm of the vector
template <typename DataType, int Size> constexpr ARCCORE_HOST_DEVICE DataType
squareNormL2(const NumVector<DataType, Size>& v)
{
  DataType norm = {};
  for (int i = 0; i < Size; ++i)
    norm += v[i] * v[i];
  return norm;
}
 
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//! Returns the L2 norm of the vector
template <typename DataType, int Size> ARCCORE_HOST_DEVICE Real
normL2(const NumVector<DataType, Size>& v)
{
  return Arcane::math::sqrt(squareNormL2(v));
}
 
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} // namespace Arcane::math
 
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#endif