pgadmin3/pgscript/utilities/m_apm/mapm5sin.cpp
2020-07-07 22:19:12 +05:00

154 lines
4.2 KiB
C++

/*
* M_APM - mapm5sin.c
*
* Copyright (C) 1999 - 2007 Michael C. Ring
*
* Permission to use, copy, and distribute this software and its
* documentation for any purpose with or without fee is hereby granted,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation.
*
* Permission to modify the software is granted. Permission to distribute
* the modified code is granted. Modifications are to be distributed by
* using the file 'license.txt' as a template to modify the file header.
* 'license.txt' is available in the official MAPM distribution.
*
* This software is provided "as is" without express or implied warranty.
*/
/*
*
* This file contains the functions that implement the sin (5x)
* and cos (4x) multiple angle relations
*
*/
#include "pgAdmin3.h"
#include "pgscript/utilities/mapm-lib/m_apm_lc.h"
/****************************************************************************/
void M_5x_sin(M_APM r, int places, M_APM x)
{
M_APM tmp8, tmp9;
tmp8 = M_get_stack_var();
tmp9 = M_get_stack_var();
m_apm_multiply(tmp9, x, MM_5x_125R); /* 1 / (5*5*5) */
M_raw_sin(tmp8, (places + 6), tmp9);
M_5x_do_it(tmp9, (places + 4), tmp8);
M_5x_do_it(tmp8, (places + 4), tmp9);
M_5x_do_it(r, places, tmp8);
M_restore_stack(2);
}
/****************************************************************************/
void M_4x_cos(M_APM r, int places, M_APM x)
{
M_APM tmp8, tmp9;
tmp8 = M_get_stack_var();
tmp9 = M_get_stack_var();
/*
* if |x| >= 1.0 use multiple angle identity 4 times
* if |x| < 1.0 use multiple angle identity 3 times
*/
if (x->m_apm_exponent > 0)
{
m_apm_multiply(tmp9, x, MM_5x_256R); /* 1 / (4*4*4*4) */
M_raw_cos(tmp8, (places + 8), tmp9);
M_4x_do_it(tmp9, (places + 8), tmp8);
M_4x_do_it(tmp8, (places + 6), tmp9);
M_4x_do_it(tmp9, (places + 4), tmp8);
M_4x_do_it(r, places, tmp9);
}
else
{
m_apm_multiply(tmp9, x, MM_5x_64R); /* 1 / (4*4*4) */
M_raw_cos(tmp8, (places + 6), tmp9);
M_4x_do_it(tmp9, (places + 4), tmp8);
M_4x_do_it(tmp8, (places + 4), tmp9);
M_4x_do_it(r, places, tmp8);
}
M_restore_stack(2);
}
/****************************************************************************/
/*
* calculate the multiple angle identity for sin (5x)
*
* sin (5x) == 16 * sin^5 (x) - 20 * sin^3 (x) + 5 * sin(x)
*/
void M_5x_do_it(M_APM rr, int places, M_APM xx)
{
M_APM tmp0, tmp1, t2, t3, t5;
tmp0 = M_get_stack_var();
tmp1 = M_get_stack_var();
t2 = M_get_stack_var();
t3 = M_get_stack_var();
t5 = M_get_stack_var();
m_apm_multiply(tmp1, xx, xx);
m_apm_round(t2, (places + 4), tmp1); /* x ^ 2 */
m_apm_multiply(tmp1, t2, xx);
m_apm_round(t3, (places + 4), tmp1); /* x ^ 3 */
m_apm_multiply(t5, t2, t3); /* x ^ 5 */
m_apm_multiply(tmp0, xx, MM_Five);
m_apm_multiply(tmp1, t5, MM_5x_Sixteen);
m_apm_add(t2, tmp0, tmp1);
m_apm_multiply(tmp1, t3, MM_5x_Twenty);
m_apm_subtract(tmp0, t2, tmp1);
m_apm_round(rr, places, tmp0);
M_restore_stack(5);
}
/****************************************************************************/
/*
* calculate the multiple angle identity for cos (4x)
*
* cos (4x) == 8 * [ cos^4 (x) - cos^2 (x) ] + 1
*/
void M_4x_do_it(M_APM rr, int places, M_APM xx)
{
M_APM tmp0, tmp1, t2, t4;
tmp0 = M_get_stack_var();
tmp1 = M_get_stack_var();
t2 = M_get_stack_var();
t4 = M_get_stack_var();
m_apm_multiply(tmp1, xx, xx);
m_apm_round(t2, (places + 4), tmp1); /* x ^ 2 */
m_apm_multiply(t4, t2, t2); /* x ^ 4 */
m_apm_subtract(tmp0, t4, t2);
m_apm_multiply(tmp1, tmp0, MM_5x_Eight);
m_apm_add(tmp0, MM_One, tmp1);
m_apm_round(rr, places, tmp0);
M_restore_stack(4);
}
/****************************************************************************/
/*
* compute r = sqrt(1 - a ^ 2).
*/
void M_cos_to_sin(M_APM r, int places, M_APM a)
{
M_APM tmp1, tmp2;
tmp1 = M_get_stack_var();
tmp2 = M_get_stack_var();
m_apm_multiply(tmp1, a, a);
m_apm_subtract(tmp2, MM_One, tmp1);
m_apm_sqrt(r, places, tmp2);
M_restore_stack(2);
}
/****************************************************************************/