WDL/cmath/test_bessel.c

   1 /*
   2   test_bessel.h
   3   Copyright (C) 2011 and later Lubomir I. Ivanov (neolit123 [at] gmail)
   4
   5   This software is provided 'as-is', without any express or implied
   6   warranty.  In no event will the authors be held liable for any damages
   7   arising from the use of this software.
   8
   9   Permission is granted to anyone to use this software for any purpose,
  10   including commercial applications, and to alter it and redistribute it
  11   freely, subject to the following restrictions:
  12
  13   1. The origin of this software must not be misrepresented; you must not
  14      claim that you wrote the original software. If you use this software
  15      in a product, an acknowledgment in the product documentation would be
  16      appreciated but is not required.
  17   2. Altered source versions must be plainly marked as such, and must not be
  18      misrepresented as being the original software.
  19   3. This notice may not be removed or altered from any source distribution.
  20 */
  21
  22 /*
  23   test bessel_polynomial.h and other related headers
  24
  25   gcc -W -Wall -Wextra -ansi pedantic
  26   cl /W4 /Za
  27
  28   reduced precisions for ansi c
  29 */
  30
  31 #include "stdio.h"
  32 #include "custom_math.h"
  33 #include "bessel_polynomial.h"
  34 #include "durand_kerner.h"
  35
  36 int main(void)
  37 {
  38   register cmath_uint16_t i = 0;
  39   register cmath_int16_t diff = 0;
  40
  41   cmath_uint32_t in_order = _BESSEL_MAX_ORDER + 1;
  42   cmath_uint16_t order;
  43   const cmath_uint16_t reverse = 1;
  44
  45   cmath_std_int_t coeff[_BESSEL_MAX_ORDER + 1];
  46
  47   cnum_t dk_coeff[_BESSEL_MAX_ORDER + 1];
  48   cnum_s dk_roots[_BESSEL_MAX_ORDER];
  49
  50   /* */
  51   #ifdef _CMATH_ANSI
  52     puts("\n\nansi c is: on");
  53   #else
  54     puts("\n\nansi c is: off");
  55   #endif
  56
  57   /* */
  58   while (in_order > _BESSEL_MAX_ORDER)
  59   {
  60     printf("\nenter order of bessel polynomial (0 - %d): ", _BESSEL_MAX_ORDER);
  61     scanf("%u", &in_order);
  62   }
  63
  64   order = (cmath_uint16_t)in_order;
  65   bessel_polynomial(coeff, order, reverse);
  66
  67   printf("\norder [N]: %d", order);
  68   printf("\nreversed bessel: %d\n\n", reverse);
  69   printf("list of coefficients:\n");
  70   while (i <= order)
  71   {
  72     printf("order[%2d]: ", (order - i));
  73     printf("%"_CMATH_PR_STD_INT"\n", coeff[i]);
  74     i++;
  75   }
  76   puts("\npolynomial:");
  77   printf("y(x) = ");
  78
  79   i = 0;
  80   while (i <= order)
  81   {
  82     diff = (cmath_int16_t)(order - i);
  83     if (diff > 0)
  84       if (coeff[i] > 1)
  85       {
  86         printf("%"_CMATH_PR_STD_INT, coeff[i]);
  87         if (diff > 1)
  88           printf("*x^%d + ", diff);
  89         else
  90           printf("*x + ");
  91       }
  92       else
  93         printf("x^%d + ", diff);
  94     else
  95       printf("%"_CMATH_PR_STD_INT"", coeff[i]);
  96     i++;
  97   }
  98
  99   /* */
 100   puts("\n\nlist roots:");
 101   i = 0;
 102   while (i < order+1)
 103   {
 104     dk_coeff[i] = (cnum_t)coeff[i];
 105     i++;
 106   }
 107
 108   durand_kerner(dk_coeff, dk_roots, order);
 109
 110   i = 0;
 111   while (i < order)
 112   {
 113     printf("root[%2d]: %.15f \t % .15f*i\n",
 114       i+1, (double)dk_roots[i].r, (double)dk_roots[i].i);
 115     i++;
 116   }
 117
 118   return 0;
 119 }