Qucs-core  0.0.19
poly.h
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00001 /*
00002  * poly.h - poly class definitions and implementation
00003  *
00004  * Copyright (C) 2005 Stefan Jahn <stefan@lkcc.org>
00005  *
00006  * This is free software; you can redistribute it and/or modify
00007  * it under the terms of the GNU General Public License as published by
00008  * the Free Software Foundation; either version 2, or (at your option)
00009  * any later version.
00010  *
00011  * This software is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  * GNU General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU General Public License
00017  * along with this package; see the file COPYING.  If not, write to
00018  * the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
00019  * Boston, MA 02110-1301, USA.
00020  *
00021  * $Id$
00022  *
00023  */
00024 
00025 #ifndef __POLY_H__
00026 #define __POLY_H__
00027 
00028 namespace qucs {
00029 
00030 class poly
00031 {
00032  public:
00033   poly (nr_double_t _x, nr_double_t _y)
00034     : x(_x), f0(_y) { f1 = f2 = 0; }
00035   poly (nr_double_t _x, nr_double_t _f0, nr_double_t _f1)
00036     : x(_x), f0(_f0), f1(_f1) { f2 = 0; }
00037   poly (nr_double_t _x, nr_double_t _f0, nr_double_t _f1, nr_double_t _f2)
00038     : x(_x), f0(_f0), f1(_f1), f2(_f2) { }
00039   ~poly ()
00040     { }
00041   nr_double_t eval (nr_double_t _x) {
00042     nr_double_t dx = _x - x; return f0 + dx * (f1 + dx * f2);
00043   }
00044 
00045   nr_double_t x;  // x     - argument
00046   nr_double_t f0; // f(x)  - value
00047   nr_double_t f1; // f'(x) - 1st derivative
00048   nr_double_t f2; // f"(x) - 2nd derivative
00049 };
00050 
00051 } // namespace qucs
00052 
00053 #endif /* __POLY_H__ */