1 /* Resampling library |
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2 * Copyright (C) <2001> David A. Schleef <ds@schleef.org> |
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3 * |
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4 * This library is free software; you can redistribute it and/or |
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5 * modify it under the terms of the GNU Library General Public |
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6 * License as published by the Free Software Foundation; either |
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7 * version 2 of the License, or any later version. |
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8 * |
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9 * This library is distributed in the hope that it will be useful, |
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10 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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12 * Library General Public License for more details. |
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13 * |
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14 * You should have received a copy of the GNU Library General Public |
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15 * License along with this library; if not, write to the |
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16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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17 * Boston, MA 02111-1307, USA. |
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18 */ |
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19 |
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20 #ifdef HAVE_CONFIG_H |
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21 #ifndef __SYMBIAN32__ |
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22 #include <config.h> |
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23 #else |
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24 #include "config.h" |
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25 #endif |
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26 #endif |
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27 |
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28 #include <string.h> |
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29 #include <math.h> |
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30 #include <stdio.h> |
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31 #include <stdlib.h> |
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32 |
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33 #include "functable.h" |
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34 #include "debug.h" |
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35 |
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36 |
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37 #ifdef __SYMBIAN32__ |
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38 EXPORT_C |
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39 #endif |
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40 |
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41 void |
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42 functable_func_sinc (double *fx, double *dfx, double x, void *closure) |
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43 { |
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44 if (x == 0) { |
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45 *fx = 1; |
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46 *dfx = 0; |
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47 return; |
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48 } |
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49 |
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50 *fx = sin (x) / x; |
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51 *dfx = (cos (x) - sin (x) / x) / x; |
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52 } |
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53 #ifdef __SYMBIAN32__ |
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54 EXPORT_C |
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55 #endif |
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56 |
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57 |
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58 void |
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59 functable_func_boxcar (double *fx, double *dfx, double x, void *closure) |
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60 { |
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61 double width = *(double *) closure; |
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62 |
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63 if (x < width && x > -width) { |
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64 *fx = 1; |
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65 } else { |
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66 *fx = 0; |
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67 } |
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68 *dfx = 0; |
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69 } |
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70 #ifdef __SYMBIAN32__ |
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71 EXPORT_C |
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72 #endif |
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73 |
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74 |
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75 void |
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76 functable_func_hanning (double *fx, double *dfx, double x, void *closure) |
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77 { |
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78 double width = *(double *) closure; |
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79 |
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80 if (x < width && x > -width) { |
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81 x /= width; |
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82 *fx = (1 - x * x) * (1 - x * x); |
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83 *dfx = -2 * 2 * x / width * (1 - x * x); |
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84 } else { |
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85 *fx = 0; |
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86 *dfx = 0; |
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87 } |
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88 } |
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89 #ifdef __SYMBIAN32__ |
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90 EXPORT_C |
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91 #endif |
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92 |
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93 |
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94 |
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95 Functable * |
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96 functable_new (void) |
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97 { |
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98 Functable *ft; |
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99 |
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100 ft = malloc (sizeof (Functable)); |
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101 memset (ft, 0, sizeof (Functable)); |
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102 |
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103 return ft; |
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104 } |
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105 #ifdef __SYMBIAN32__ |
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106 EXPORT_C |
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107 #endif |
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108 |
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109 |
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110 void |
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111 functable_free (Functable * ft) |
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112 { |
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113 free (ft); |
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114 } |
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115 #ifdef __SYMBIAN32__ |
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116 EXPORT_C |
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117 #endif |
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118 |
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119 |
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120 void |
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121 functable_set_length (Functable * t, int length) |
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122 { |
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123 t->length = length; |
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124 } |
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125 #ifdef __SYMBIAN32__ |
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126 EXPORT_C |
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127 #endif |
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128 |
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129 |
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130 void |
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131 functable_set_offset (Functable * t, double offset) |
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132 { |
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133 t->offset = offset; |
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134 } |
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135 #ifdef __SYMBIAN32__ |
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136 EXPORT_C |
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137 #endif |
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138 |
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139 |
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140 void |
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141 functable_set_multiplier (Functable * t, double multiplier) |
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142 { |
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143 t->multiplier = multiplier; |
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144 } |
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145 #ifdef __SYMBIAN32__ |
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146 EXPORT_C |
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147 #endif |
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148 |
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149 |
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150 void |
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151 functable_calculate (Functable * t, FunctableFunc func, void *closure) |
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152 { |
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153 int i; |
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154 double x; |
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155 |
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156 if (t->fx) |
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157 free (t->fx); |
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158 if (t->dfx) |
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159 free (t->dfx); |
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160 |
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161 t->fx = malloc (sizeof (double) * (t->length + 1)); |
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162 t->dfx = malloc (sizeof (double) * (t->length + 1)); |
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163 |
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164 t->inv_multiplier = 1.0 / t->multiplier; |
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165 |
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166 for (i = 0; i < t->length + 1; i++) { |
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167 x = t->offset + t->multiplier * i; |
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168 |
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169 func (&t->fx[i], &t->dfx[i], x, closure); |
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170 } |
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171 } |
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172 #ifdef __SYMBIAN32__ |
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173 EXPORT_C |
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174 #endif |
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175 |
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176 |
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177 void |
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178 functable_calculate_multiply (Functable * t, FunctableFunc func, void *closure) |
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179 { |
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180 int i; |
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181 double x; |
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182 |
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183 for (i = 0; i < t->length + 1; i++) { |
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184 double afx, adfx, bfx, bdfx; |
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185 |
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186 afx = t->fx[i]; |
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187 adfx = t->dfx[i]; |
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188 x = t->offset + t->multiplier * i; |
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189 func (&bfx, &bdfx, x, closure); |
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190 t->fx[i] = afx * bfx; |
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191 t->dfx[i] = afx * bdfx + adfx * bfx; |
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192 } |
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193 |
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194 } |
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195 #ifdef __SYMBIAN32__ |
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196 EXPORT_C |
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197 #endif |
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198 |
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199 |
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200 double |
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201 functable_evaluate (Functable * t, double x) |
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202 { |
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203 int i; |
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204 double f0, f1, w0, w1; |
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205 double x2, x3; |
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206 double w; |
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207 |
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208 if (x < t->offset || x > (t->offset + t->length * t->multiplier)) { |
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209 RESAMPLE_DEBUG ("x out of range %g", x); |
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210 } |
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211 |
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212 x -= t->offset; |
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213 x *= t->inv_multiplier; |
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214 i = floor (x); |
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215 x -= i; |
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216 |
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217 x2 = x * x; |
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218 x3 = x2 * x; |
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219 |
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220 f1 = 3 * x2 - 2 * x3; |
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221 f0 = 1 - f1; |
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222 w0 = (x - 2 * x2 + x3) * t->multiplier; |
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223 w1 = (-x2 + x3) * t->multiplier; |
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224 |
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225 w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1; |
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226 |
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227 /*w = t->fx[i] * (1-x) + t->fx[i+1] * x; */ |
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228 |
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229 return w; |
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230 } |
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231 #ifdef __SYMBIAN32__ |
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232 EXPORT_C |
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233 #endif |
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234 |
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235 |
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236 |
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237 double |
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238 functable_fir (Functable * t, double x, int n, double *data, int len) |
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239 { |
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240 int i, j; |
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241 double f0, f1, w0, w1; |
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242 double x2, x3; |
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243 double w; |
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244 double sum; |
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245 |
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246 x -= t->offset; |
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247 x /= t->multiplier; |
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248 i = floor (x); |
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249 x -= i; |
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250 |
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251 x2 = x * x; |
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252 x3 = x2 * x; |
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253 |
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254 f1 = 3 * x2 - 2 * x3; |
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255 f0 = 1 - f1; |
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256 w0 = (x - 2 * x2 + x3) * t->multiplier; |
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257 w1 = (-x2 + x3) * t->multiplier; |
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258 |
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259 sum = 0; |
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260 for (j = 0; j < len; j++) { |
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261 w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1; |
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262 sum += data[j * 2] * w; |
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263 i += n; |
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264 } |
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265 |
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266 return sum; |
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267 } |
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268 #ifdef __SYMBIAN32__ |
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269 EXPORT_C |
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270 #endif |
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271 |
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272 |
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273 void |
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274 functable_fir2 (Functable * t, double *r0, double *r1, double x, |
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275 int n, double *data, int len) |
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276 { |
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277 int i, j; |
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278 double f0, f1, w0, w1; |
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279 double x2, x3; |
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280 double w; |
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281 double sum0, sum1; |
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282 double floor_x; |
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283 |
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284 x -= t->offset; |
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285 x *= t->inv_multiplier; |
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286 floor_x = floor (x); |
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287 i = floor_x; |
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288 x -= floor_x; |
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289 |
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290 x2 = x * x; |
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291 x3 = x2 * x; |
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292 |
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293 f1 = 3 * x2 - 2 * x3; |
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294 f0 = 1 - f1; |
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295 w0 = (x - 2 * x2 + x3) * t->multiplier; |
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296 w1 = (-x2 + x3) * t->multiplier; |
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297 |
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298 sum0 = 0; |
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299 sum1 = 0; |
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300 for (j = 0; j < len; j++) { |
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301 w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1; |
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302 sum0 += data[j * 2] * w; |
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303 sum1 += data[j * 2 + 1] * w; |
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304 i += n; |
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305 } |
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306 |
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307 *r0 = sum0; |
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308 *r1 = sum1; |
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309 } |
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