include/a/poly.h

   1 /*!
   2  @file poly.h
   3  @brief polynomial
   4 */
   5
   6 #ifndef LIBA_POLY_H
   7 #define LIBA_POLY_H
   8
   9 #include "a.h"
  10
  11 /*!
  12  @ingroup A
  13  @addtogroup A_POLY polynomial
  14  @{
  15 */
  16
  17 #if defined(__cplusplus)
  18 extern "C" {
  19 #endif /* __cplusplus */
  20 #if defined(LIBA_POLY_C)
  21 #undef A_INTERN
  22 #define A_INTERN A_INLINE
  23 #endif /* LIBA_POLY_C */
  24
  25 /*!
  26  @brief swap between \f$ \sum_{i=0}^{n}a_{i}x^{i} \f$ and \f$ \sum_{i=0}^{n}a_{i}x^{n-i} \f$
  27 */
  28 A_EXTERN a_float *a_poly_swap(a_float *a, a_size n);
  29
  30 /*!
  31  @brief horner function for polynomial \f$ \sum_{i=0}^{n}a_{i}x^{i} \f$
  32  \f[
  33   \left\{\begin{array}{l}
  34   S_n = a_n\\
  35   S_i = xS_{i+1} + a_i,\quad(i=n-1,n-2,\cdots,1,0)\\
  36   P(x) = S_0
  37   \end{array}\right.
  38  \f]
  39 */
  40 #if !defined A_HAVE_INLINE || defined(LIBA_POLY_C)
  41 A_EXTERN a_float a_poly_eval(a_float const *a, a_size n, a_float x);
  42 #endif /* A_HAVE_INLINE */
  43 A_EXTERN a_float a_poly_eval_(a_float const *a, a_float const *b, a_float x);
  44 #if defined(A_HAVE_INLINE) || defined(LIBA_POLY_C)
  45 A_INTERN a_float a_poly_eval(a_float const *a, a_size n, a_float x)
  46 {
  47     return n ? a_poly_eval_(a, a + n, x) : 0;
  48 }
  49 #endif /* A_HAVE_INLINE */
  50
  51 /*!
  52  @brief horner function for polynomial \f$ \sum_{i=0}^{n}a_{i}x^{n-i} \f$
  53  \f[
  54   \left\{\begin{array}{l}
  55   S_0 = a_0\\
  56   S_i = xS_{i-1} + a_i,\quad(i=1,2,\cdots,n-1,n)\\
  57   P(x) = S_n
  58   \end{array}\right.
  59  \f]
  60 */
  61 #if !defined A_HAVE_INLINE || defined(LIBA_POLY_C)
  62 A_EXTERN a_float a_poly_evar(a_float const *a, a_size n, a_float x);
  63 #endif /* A_HAVE_INLINE */
  64 A_EXTERN a_float a_poly_evar_(a_float const *a, a_float const *b, a_float x);
  65 #if defined(A_HAVE_INLINE) || defined(LIBA_POLY_C)
  66 A_INTERN a_float a_poly_evar(a_float const *a, a_size n, a_float x)
  67 {
  68     return n ? a_poly_evar_(a, a + n, x) : 0;
  69 }
  70 #endif /* A_HAVE_INLINE */
  71
  72 #if defined(LIBA_POLY_C)
  73 #undef A_INTERN
  74 #define A_INTERN static A_INLINE
  75 #endif /* LIBA_POLY_C */
  76 #if defined(__cplusplus)
  77 } /* extern "C" */
  78 #endif /* __cplusplus */
  79
  80 /*! @} A_POLY */
  81
  82 #endif /* a/poly.h */