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authorMystery Man <unknown@mandriva.org>2003-08-20 07:37:27 +0000
committerMystery Man <unknown@mandriva.org>2003-08-20 07:37:27 +0000
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This commit was manufactured by cvs2svn to create branch 'MDKC_1_0'.topic/MDKC_1_0
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+/*--------------------------------------------------------------------------*
+
+Name __poly - generates a polynomial from arguments
+
+Usage double __poly ( double x, int n, const double* c );
+
+Prototype in math.h
+
+Description __poly generates a polynomial in x, of degree n, with
+ coefficients c[0], c[1], ..., c[n]. For example, if n=4,
+ the generated polynomial is
+
+ c[4]*x^4 + c[3]*x^3 + c[2]*x^2 + c[1]*x + c[0]
+
+ The polynomial is calculated using Horner's method:
+
+ polynom = (..((x*c[n] + c[n-1])*x + c[n-2])..)*x + c[0]
+
+Return value __poly returns the value of the polynomial as evaluated for
+ the given x.
+ A range error occurs if the result exceeds double range.
+
+*---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+#include "dietlibm.h"
+
+double __poly ( double x, size_t n, const double* c)
+{
+ long double ret;
+ size_t i;
+
+ i = n;
+ c += n;
+ ret = 0;
+ do
+ ret = ret * x + *c--;
+ while ( i-- );
+
+ return ret;
+}