72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/*
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horner.h
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Copyright (C) 2011 and later Lubomir I. Ivanov (neolit123 [at] gmail)
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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/*
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algorithm to evaluate integer order polynomials using horner's scheme.
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*/
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#ifndef _HORNER_H_
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#define _HORNER_H_
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#include "custom_math.h"
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#include "complex_number.h"
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/* settings */
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#ifndef _HORNER_INLINE
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#define _HORNER_INLINE _CMATH_INLINE
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#else
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#define _HORNER_INLINE
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#endif
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/* real */
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_HORNER_INLINE
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cmath_t horner_eval
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(const cmath_t *coeff, const cmath_t x, cmath_uint16_t order)
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{
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register cmath_t y = coeff[0];
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register cmath_uint16_t n = 1;
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order += 1;
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while(n < order)
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{
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y = y*x + coeff[n];
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n++;
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}
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return y;
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}
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/* complex */
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_HORNER_INLINE
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cnum_s horner_eval_c
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(const cnum_s *coeff, const cnum_s x, cmath_uint16_t order)
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{
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register cmath_uint16_t n = 1;
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cnum_s y = coeff[0];
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order += 1;
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while(n < order)
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{
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y = cnum_add(cnum_mul(y, x), coeff[n]);
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n++;
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}
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return y;
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}
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#endif /* _HORNER_H_ */
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