#include "mconf.h" /* chbevl.c * * Evaluate Chebyshev series * * * * SYNOPSIS : * * int N ; * double x , y , coef [ N ] , chebevl ( ) ; * * y = chbevl ( x , coef , N ) ; * * * * DESCRIPTION : * * Evaluates the series * * N - 1 * - ' * y = > coef [ i ] T ( x / 2 ) * - i * i = 0 * * of Chebyshev polynomials Ti at argument x / 2 . * * Coefficients are stored in reverse order , i . e . the zero * order term is last in the array . Note N is the number of * coefficients , not the order . * * If coefficients are for the interval a to b , x must * have been transformed to x - > 2 ( 2 x - b - a ) / ( b - a ) before * entering the routine . This maps x from ( a , b ) to ( - 1 , 1 ) , * over which the Chebyshev polynomials are defined . * * If the coefficients are for the inverted interval , in * which ( a , b ) is mapped to ( 1 / b , 1 / a ) , the transformation * required is x - > 2 ( 2 ab / x - b - a ) / ( b - a ) . If b is infinity , * this becomes x - > 4 a / x - 1 . * * * * SPEED : * * Taking advantage of the recurrence properties of the * Chebyshev polynomials , the routine requires one more * addition per loop than evaluating a nested polynomial of * the same degree . * /* chbevl.c */ /*Cephes Math Library Release 2 . 0 : April , 1987 Copyright 1985 , 1987 by Stephen L . Moshier Direct inquiries to 30 Frost Street , Cambridge , MA 02140 double chbevl(x, array, n) double x;double array[];int n;double b0, b1, b2, *p;int i;0 .0 ;1 ;do {while (--i);return (0 .5 * (b0 - b2));
Messung V0.5 in Prozent C=97 H=92 G=94
¤ Dauer der Verarbeitung: 0.4 Sekunden
¤ *© Formatika GbR, Deutschland
