source/blender/blenlib/BLI_math_statistics.h

   1 /* SPDX-FileCopyrightText: 2015 Blender Authors
   2  *
   3  * SPDX-License-Identifier: GPL-2.0-or-later */
   4
   5 #pragma once
   6
   7 /** \file
   8  * \ingroup bli
   9  */
  10
  11 #include "BLI_math_inline.h"
  12 #include "BLI_sys_types.h"
  13
  14 #ifdef __cplusplus
  15 extern "C" {
  16 #endif
  17
  18 #ifdef BLI_MATH_GCC_WARN_PRAGMA
  19 #  pragma GCC diagnostic push
  20 #  pragma GCC diagnostic ignored "-Wredundant-decls"
  21 #endif
  22
  23 /* -------------------------------------------------------------------- */
  24 /** \name Covariance Matrices
  25  * \{ */
  26
  27 /**
  28  * \brief Compute the covariance matrix of given set of nD coordinates.
  29  *
  30  * \param n: the dimension of the vectors (and hence, of the covariance matrix to compute).
  31  * \param cos_vn: the nD points to compute covariance from.
  32  * \param cos_vn_num: the number of nD coordinates in cos_vn.
  33  * \param center: the center (or mean point) of cos_vn. If NULL,
  34  * it is assumed cos_vn is already centered.
  35  * \param use_sample_correction: whether to apply sample correction
  36  *                              (i.e. get 'sample variance' instead of 'population variance').
  37  * \return r_covmat the computed covariance matrix.
  38  */
  39 void BLI_covariance_m_vn_ex(int n,
  40                             const float *cos_vn,
  41                             int cos_vn_num,
  42                             const float *center,
  43                             bool use_sample_correction,
  44                             float *r_covmat);
  45 /**
  46  * \brief Compute the covariance matrix of given set of 3D coordinates.
  47  *
  48  * \param cos_v3: the 3D points to compute covariance from.
  49  * \param cos_v3_num: the number of 3D coordinates in cos_v3.
  50  * \return r_covmat the computed covariance matrix.
  51  * \return r_center the computed center (mean) of 3D points (may be NULL).
  52  */
  53 void BLI_covariance_m3_v3n(const float (*cos_v3)[3],
  54                            int cos_v3_num,
  55                            bool use_sample_correction,
  56                            float r_covmat[3][3],
  57                            float r_center[3]);
  58
  59 #ifdef BLI_MATH_GCC_WARN_PRAGMA
  60 #  pragma GCC diagnostic pop
  61 #endif
  62
  63 /** \} */
  64
  65 #ifdef __cplusplus
  66 }
  67 #endif