00001 // 00002 // Copyright(c) 1993-1996 Tony Kirke 00003 // author="Tony Kirke" * 00004 /* 00005 * SPUC - Signal processing using C++ - A DSP library 00006 * 00007 * This program is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License as published by 00009 * the Free Software Foundation; either version 2, or (at your option) 00010 * any later version. 00011 * 00012 * This program is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 * GNU General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU General Public License 00018 * along with this program; if not, write to the Free Software 00019 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00020 */ 00021 #ifndef IIR_SHELF 00022 #define IIR_SHELF 00023 namespace SPUC { 00026 // 00033 template <class Numeric> class iir_shelf 00034 { 00035 protected: 00036 double a; 00037 double b; 00038 Numeric out; 00039 Numeric previous_out; 00040 Numeric previous_in; 00041 00042 public: 00043 iir_shelf(double A=0,double B=0) : a(A),b(B) { 00044 previous_in = previous_out = out = 0 ; } 00046 Numeric clock(Numeric input) { 00047 // Shift previous outputs and calculate new output */ 00048 out = ((1-b)*previous_out + (a+1)*input + (a-1)*previous_in)/(1+b); 00049 previous_out = out; 00050 previous_in = input; 00051 return(out); 00052 } 00054 void reset() { 00055 previous_in = previous_out = out = 0; 00056 } 00057 }; 00058 } // namespace SPUC 00059 #endif