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/* __polevll.c
* __p1evll.c
*
* Evaluate polynomial
*
*
*
* SYNOPSIS:
*
* int N;
* long double x, y, coef[N+1], __polevl[];
*
* y = __polevll( x, coef, N );
*
*
*
* DESCRIPTION:
*
* Evaluates polynomial of degree N:
*
* 2 N
* y = C + C x + C x +...+ C x
* 0 1 2 N
*
* Coefficients are stored in reverse order:
*
* coef[0] = C , ..., coef[N] = C .
* N 0
*
* The function __p1evll() assumes that coef[N] = 1.0 and is
* omitted from the array. Its calling arguments are
* otherwise the same as polevll().
*
* SPEED:
*
* In the interest of speed, there are no checks for out
* of bounds arithmetic. This routine is used by most of
* the functions in the library. Depending on available
* equipment features, the user may wish to rewrite the
* program in microcode or assembly language.
*
*/
/* Polynomial evaluator:
* P[0] x^n + P[1] x^(n-1) + ... + P[n]
*/
long double __polevll( x, P, n )
long double x;
long double *P;
int n;
{
register long double y;
y = *P++;
do
{
y = y * x + *P++;
}
while( --n );
return(y);
}
/* Polynomial evaluator:
* x^n + P[0] x^(n-1) + P[1] x^(n-2) + ... + P[n]
*/
long double __p1evll( x, P, n )
long double x;
long double *P;
int n;
{
register long double y;
n -= 1;
y = x + *P++;
do
{
y = y * x + *P++;
}
while( --n );
return( y );
}
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