127 lines
2.5 KiB
MQL5
127 lines
2.5 KiB
MQL5
|
//+------------------------------------------------------------------+
|
||
|
|
//| polevl.mqh |
|
||
|
|
//| Copyright 2025, MetaQuotes Ltd. |
|
||
|
|
//| https://www.mql5.com |
|
||
|
|
//+------------------------------------------------------------------+
|
||
|
|
#property copyright "Copyright 2025, MetaQuotes Ltd."
|
||
|
|
#property link "https://www.mql5.com"
|
||
|
|
#include"config.mqh"
|
||
|
|
|
||
|
|
namespace special
|
||
|
|
{
|
||
|
|
namespace cephes
|
||
|
|
{
|
||
|
|
inline double polevl(double x, double &coef[], int N)
|
||
|
|
{
|
||
|
|
double ans;
|
||
|
|
int i;
|
||
|
|
int p;
|
||
|
|
|
||
|
|
p = 0;
|
||
|
|
ans = coef[p++];
|
||
|
|
i = N;
|
||
|
|
|
||
|
|
do
|
||
|
|
{
|
||
|
|
ans = ans * x + coef[p++];
|
||
|
|
}
|
||
|
|
while(--i != 0);
|
||
|
|
|
||
|
|
return (ans);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* p1evl() */
|
||
|
|
/* N
|
||
|
|
* Evaluate polynomial when coefficient of x is 1.0.
|
||
|
|
* That is, C_{N} is assumed to be 1, and that coefficient
|
||
|
|
* is not included in the input array coef.
|
||
|
|
* coef must have length N and contain the polynomial coefficients
|
||
|
|
* stored as
|
||
|
|
* coef[0] = C_{N-1}
|
||
|
|
* coef[1] = C_{N-2}
|
||
|
|
* ...
|
||
|
|
* coef[N-2] = C_1
|
||
|
|
* coef[N-1] = C_0
|
||
|
|
* Otherwise same as polevl.
|
||
|
|
*/
|
||
|
|
|
||
|
|
inline double p1evl(double x, double &coef[], int N)
|
||
|
|
{
|
||
|
|
double ans;
|
||
|
|
int p;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
p = 0;
|
||
|
|
ans = x + coef[p++];
|
||
|
|
i = N - 1;
|
||
|
|
|
||
|
|
do
|
||
|
|
ans = ans * x + coef[p++];
|
||
|
|
while(--i != 0);
|
||
|
|
|
||
|
|
return (ans);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Evaluate a rational function. See [1]. */
|
||
|
|
|
||
|
|
/* The function ratevl is only used once in cephes/lanczos.h. */
|
||
|
|
inline double ratevl(double x, double &num[], int M, double &denom[], int N)
|
||
|
|
{
|
||
|
|
int i, dir;
|
||
|
|
double y, num_ans, denom_ans;
|
||
|
|
double absx = abs(x);
|
||
|
|
int p;
|
||
|
|
|
||
|
|
if(absx > 1)
|
||
|
|
{
|
||
|
|
/* Evaluate as a polynomial in 1/x. */
|
||
|
|
dir = -1;
|
||
|
|
p = M;
|
||
|
|
y = 1 / x;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
dir = 1;
|
||
|
|
p = 0;
|
||
|
|
y = x;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Evaluate the numerator */
|
||
|
|
num_ans = num[p];
|
||
|
|
p += dir;
|
||
|
|
for(i = 1; i <= M; i++)
|
||
|
|
{
|
||
|
|
num_ans = num_ans * y + num[p];
|
||
|
|
p += dir;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Evaluate the denominator */
|
||
|
|
if(absx > 1)
|
||
|
|
{
|
||
|
|
p = N;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
p = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
denom_ans = denom[p];
|
||
|
|
p += dir;
|
||
|
|
for(i = 1; i <= N; i++)
|
||
|
|
{
|
||
|
|
denom_ans = denom_ans * y + denom[p];
|
||
|
|
p += dir;
|
||
|
|
}
|
||
|
|
|
||
|
|
if(absx > 1)
|
||
|
|
{
|
||
|
|
i = M - N;
|
||
|
|
return pow(x, i) * num_ans / denom_ans;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
return num_ans / denom_ans;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} // namespace cephes
|
||
|
|
} // namespace special
|