Total Complexity | 45 |
Total Lines | 466 |
Duplicated Lines | 0 % |
Changes | 0 |
Complex classes like SequenceProvider often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use SequenceProvider, and based on these observations, apply Extract Interface, too.
1 | <?php |
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19 | class SequenceProvider |
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20 | { |
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21 | |||
22 | const EULER_ZIGZAG = [ |
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23 | '1', // 0 |
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24 | '1', // 1 |
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25 | '1', // 2 |
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26 | '2', // 3 |
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27 | '5', // 4 |
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28 | '16', // 5 |
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29 | '61', // 6 |
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30 | '272', // 7 |
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31 | '1385', // 8 |
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32 | '7936', // 9 |
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33 | '50521', // 10 |
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34 | '353792', // 11 |
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35 | '2702765', // 12 |
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36 | '22368256', // 13 |
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37 | '199360981', // 14 |
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38 | '1903757312', // 15 |
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39 | '19391512145', // 16 |
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40 | '209865342976', // 17 |
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41 | '2404879675441', // 18 |
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42 | '29088885112832', // 19 |
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43 | '370371188237525', // 20 |
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44 | '4951498053124096', // 21 |
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45 | '69348874393137901', // 22 |
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46 | '1015423886506852352', // 23 |
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47 | '15514534163557086905', // 24 |
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48 | '246921480190207983616', // 25 |
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49 | '4087072509293123892361', // 26 |
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50 | '70251601603943959887872', // 27 |
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51 | '1252259641403629865468285', // 28 |
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52 | '23119184187809597841473536', // 29 |
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53 | '441543893249023104553682821', // 30 |
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54 | '8713962757125169296170811392', // 31 |
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55 | '177519391579539289436664789665', // 32 |
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56 | '3729407703720529571097509625856', // 33 |
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57 | '80723299235887898062168247453281', // 34 |
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58 | '1798651693450888780071750349094912', // 35 |
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59 | '41222060339517702122347079671259045', // 36 |
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60 | '970982810785059112379399707952152576', // 37 |
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61 | '23489580527043108252017828576198947741', // 38 |
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62 | '583203324917310043943191641625494290432', // 39 |
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63 | '14851150718114980017877156781405826684425', // 40 |
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64 | '387635983772083031828014624002175135645696', // 41 |
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65 | '10364622733519612119397957304745185976310201', // 42 |
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66 | '283727921907431909304183316295787837183229952', // 43 |
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67 | '7947579422597592703608040510088070619519273805', // 44 |
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68 | '227681379129930886488600284336316164603920777216', // 45 |
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69 | '6667537516685544977435028474773748197524107684661', // 46 |
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70 | '199500252157859031027160499643195658166340757225472', // 47 |
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71 | '6096278645568542158691685742876843153976539044435185', // 48 |
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72 | '190169564657928428175235445073924928592047775873499136', // 49 |
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73 | '6053285248188621896314383785111649088103498225146815121', // 50 |
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74 | ]; |
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75 | |||
76 | /** |
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77 | * OEIS: A005408 |
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78 | * |
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79 | * @param int $n |
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80 | * @param bool $asCollection |
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81 | * @param int $collectionSize |
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82 | * |
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83 | * @return ImmutableDecimal|NumberCollection |
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84 | * @throws IntegrityConstraint |
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85 | * @throws MissingPackage |
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86 | */ |
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87 | public static function nthOddNumber(int $n, bool $asCollection = false, int $collectionSize = 10): ImmutableDecimal|NumberCollection |
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88 | { |
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89 | if ($asCollection) { |
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90 | $sequence = new NumberCollection(); |
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91 | |||
92 | for ($i = 0;$i < $collectionSize;$i++) { |
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93 | $sequence->push(self::nthOddNumber($n + $i)); |
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94 | } |
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95 | |||
96 | return $sequence; |
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97 | } |
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98 | |||
99 | if ($n >= (PHP_INT_MAX/2)) { |
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100 | $n = new ImmutableDecimal($n, 100); |
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101 | |||
102 | return $n->multiply(2)->add(1); |
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103 | } else { |
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104 | return new ImmutableDecimal(($n*2)+1, 100); |
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105 | } |
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106 | |||
107 | } |
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108 | |||
109 | /** |
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110 | * OEIS: A005843 |
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111 | * |
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112 | * @param int $n |
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113 | * @param int|null $scale |
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114 | * @param bool $asCollection |
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115 | * @param int $collectionSize |
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116 | * |
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117 | * @return ImmutableDecimal|NumberCollection |
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118 | * @throws IntegrityConstraint |
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119 | */ |
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120 | public static function nthEvenNumber(int $n, int $scale = null, bool $asCollection = false, int $collectionSize = 10): ImmutableDecimal|NumberCollection |
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121 | { |
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122 | |||
123 | if ($asCollection) { |
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124 | $sequence = new NumberCollection(); |
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125 | |||
126 | for ($i = 0;$i < $collectionSize;$i++) { |
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127 | $sequence->push(self::nthEvenNumber($n + $i)); |
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128 | } |
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129 | |||
130 | return $sequence; |
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131 | } |
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132 | if ($n > (PHP_INT_MAX/2)) { |
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133 | $n = Numbers::makeOrDont(Numbers::IMMUTABLE, $n, $scale); |
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134 | |||
135 | return $n->multiply(2); |
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136 | } else { |
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137 | return new ImmutableDecimal(($n*2), $scale); |
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138 | } |
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139 | |||
140 | } |
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141 | |||
142 | /** |
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143 | * OEIS: A033999 |
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144 | * |
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145 | * @param int $n |
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146 | * @param bool $asCollection |
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147 | * @param int $collectionSize |
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148 | * |
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149 | * @return ImmutableDecimal|NumberCollection |
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150 | * @throws IntegrityConstraint |
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151 | */ |
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152 | public static function nthPowerNegativeOne(int $n, bool $asCollection = false, int $collectionSize = 10): ImmutableDecimal|NumberCollection |
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153 | { |
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154 | |||
155 | if ($asCollection) { |
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156 | $sequence = new NumberCollection(); |
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157 | |||
158 | for ($i = 0;$i < $collectionSize;$i++) { |
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159 | $sequence->push(self::nthPowerNegativeOne($n + $i)); |
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160 | } |
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161 | |||
162 | return $sequence; |
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163 | } |
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164 | |||
165 | return ($n % 2 ? new ImmutableDecimal(-1) : new ImmutableDecimal(1)); |
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166 | |||
167 | } |
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168 | |||
169 | /** |
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170 | * OEIS: A000111 |
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171 | * |
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172 | * @param int $n |
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173 | * @param bool $asCollection |
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174 | * @param int $collectionSize |
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175 | * |
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176 | * @return ImmutableDecimal|NumberCollection |
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177 | * @throws IntegrityConstraint |
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178 | */ |
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179 | public static function nthEulerZigzag(int $n, bool $asCollection = false, int $collectionSize = 10): ImmutableDecimal|NumberCollection |
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180 | { |
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181 | |||
182 | if ($asCollection) { |
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183 | $sequence = new NumberCollection(); |
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184 | |||
185 | for ($i = 0;$i < $collectionSize;$i++) { |
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186 | $sequence->push(self::nthEulerZigzag($n + $i)); |
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187 | } |
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188 | |||
189 | return $sequence; |
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190 | } |
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191 | |||
192 | if ($n > 50) { |
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193 | throw new IntegrityConstraint( |
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194 | '$n cannot be larger than 50', |
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195 | 'Limit your use of the Euler Zigzag Sequence to the 50th index', |
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196 | 'This library does not support the Euler Zigzag Sequence (OEIS: A000111) beyond E(50)' |
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197 | ); |
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198 | } |
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199 | |||
200 | return Numbers::make(Numbers::IMMUTABLE, static::EULER_ZIGZAG[$n], 100); |
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201 | |||
202 | } |
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203 | |||
204 | /** |
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205 | * Returns the nth Bernoulli Number, where odd indexes return zero, and B1() is -1/2. |
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206 | * |
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207 | * This function gets very slow if you demand large precision. |
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208 | * |
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209 | * @param $n |
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210 | * @param int|null $scale |
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211 | * @return ImmutableDecimal |
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212 | * @throws IncompatibleObjectState |
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213 | * @throws IntegrityConstraint |
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214 | * @throws MissingPackage |
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215 | */ |
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216 | public static function nthBernoulliNumber($n, ?int $scale = null): ImmutableDecimal |
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217 | { |
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218 | |||
219 | $scale = $scale ?? 5; |
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220 | |||
221 | $internalScale = (int)ceil($scale*(log10($scale)+1)); |
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222 | |||
223 | $n = Numbers::makeOrDont(Numbers::IMMUTABLE, $n, $internalScale)->setMode(CalcMode::Precision); |
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224 | |||
225 | if (!$n->isWhole()) { |
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226 | throw new IntegrityConstraint( |
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227 | 'Only integers may be indexes for Bernoulli numbers', |
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228 | 'Ensure only integers are provided as indexes', |
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229 | 'An attempt was made to get a Bernoulli number with a non-integer index' |
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230 | ); |
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231 | } |
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232 | |||
233 | if ($n->isLessThan(0)) { |
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234 | throw new IntegrityConstraint( |
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235 | 'Index must be non-negative', |
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236 | 'Provide only non-negative indexes for Bernoulli number generation', |
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237 | 'An attempt was made to get a Bernoulli number with a negative index' |
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238 | ); |
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239 | } |
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240 | |||
241 | if ($n->isEqual(0)) { |
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242 | return Numbers::makeOne($scale); |
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243 | } |
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244 | |||
245 | if ($n->isEqual(1)) { |
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246 | return Numbers::make(Numbers::IMMUTABLE, '-0.5', $scale); |
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247 | } |
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248 | |||
249 | if ($n->modulo(2)->isEqual(1)) { |
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250 | return Numbers::makeZero($scale); |
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251 | } |
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252 | |||
253 | $tau = Numbers::makeTau($internalScale)->setMode(CalcMode::Precision); |
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254 | |||
255 | $d = Numbers::make(Numbers::IMMUTABLE, 4, $internalScale)->setMode(CalcMode::Precision)->add( |
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256 | $n->factorial()->ln($internalScale)->subtract( |
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257 | $n->multiply($tau->log10($internalScale)) |
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258 | )->truncate() |
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259 | )->add( |
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260 | $n->numberOfIntDigits() |
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261 | ); |
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262 | $s = $d->multiply( |
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263 | Numbers::makeNaturalLog10($internalScale) |
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264 | )->multiply( |
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265 | '0.5' |
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266 | )->divide($n, $internalScale)->exp($internalScale)->truncate()->add(1); |
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267 | $internalScale = ($d->isGreaterThan($internalScale)) ? $d->asInt() : $internalScale; |
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268 | |||
269 | $s = $s->truncateToScale($internalScale); |
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270 | $n = $n->truncateToScale($internalScale); |
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271 | $tau = Numbers::make2Pi($internalScale)->setMode(CalcMode::Precision); |
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272 | $p = Numbers::makeOne($internalScale)->setMode(CalcMode::Precision); |
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273 | $t1 = Numbers::makeOne($internalScale)->setMode(CalcMode::Precision); |
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274 | $t2 = Numbers::makeOne($internalScale)->setMode(CalcMode::Precision); |
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275 | |||
276 | while ($p->isLessThanOrEqualTo($s)) { |
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277 | $p = self::_nextprime($p); |
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278 | $pn = $p->pow($n); |
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279 | $pn1 = $pn->subtract(1); |
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280 | $t1 = $pn->multiply($t1); |
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281 | $t2 = $pn1->multiply($t2); |
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282 | } |
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283 | |||
284 | $z = $t1->divide($t2, $internalScale); |
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285 | $oz = Numbers::makeZero($internalScale)->setMode(CalcMode::Precision); |
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286 | |||
287 | while (!$oz->isEqual($z)) { |
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288 | $oz = $z; |
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289 | $p = self::_nextprime($p); |
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290 | $pn = $p->pow($n); |
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291 | $pn1 = $z->divide($pn, $internalScale); |
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292 | $z = $z->add($pn1); |
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293 | } |
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294 | |||
295 | $f = $n->factorial(); |
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296 | $taun = $tau->pow($n); |
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297 | |||
298 | $z = $z->multiply(2)->multiply($f)->divide($taun, $internalScale); |
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299 | |||
300 | if ($n->modulo(4)->isEqual(0)) { |
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301 | $z = $z->multiply(-1); |
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302 | } |
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303 | |||
304 | return $z->round($scale); |
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305 | |||
306 | } |
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307 | |||
308 | /** |
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309 | * @param int $n |
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310 | * @return NumberCollection |
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311 | * @throws IntegrityConstraint |
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312 | * @throws MissingPackage |
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313 | */ |
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314 | public static function nthPrimeNumbers(int $n): NumberCollection |
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315 | { |
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316 | $collection = new NumberCollection(); |
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317 | |||
318 | $collection->push(Numbers::make(Numbers::IMMUTABLE, 2)); |
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319 | |||
320 | $currentPrime = Numbers::make(Numbers::IMMUTABLE, 3); |
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321 | |||
322 | for ($i = 1;$i < $n;$i++) { |
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323 | while (!$currentPrime->isPrime()) { |
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324 | $currentPrime = $currentPrime->add(2); |
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325 | } |
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326 | |||
327 | $collection->push($currentPrime); |
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328 | $currentPrime = $currentPrime->add(2); |
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329 | } |
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330 | |||
331 | return $collection; |
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332 | } |
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333 | |||
334 | /** |
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335 | * OEIS: A000045 |
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336 | * |
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337 | * This uses an implementation of the fast-doubling Karatsuba multiplication algorithm as described by 'Nayuki': |
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338 | * |
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339 | * https://www.nayuki.io/page/fast-fibonacci-algorithms |
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340 | * |
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341 | * @param int $n |
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342 | * @param bool $asCollection |
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343 | * @param int $collectionSize |
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344 | * |
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345 | * @return ImmutableDecimal|NumberCollection |
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346 | * @throws IntegrityConstraint |
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347 | */ |
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348 | public static function nthFibonacciNumber(int $n, bool $asCollection = false, int $collectionSize = 10): ImmutableDecimal|NumberCollection |
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349 | { |
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350 | $n = Numbers::makeOrDont(Numbers::IMMUTABLE, $n); |
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351 | |||
352 | if ($n->isLessThan(0)) { |
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353 | throw new IntegrityConstraint( |
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354 | 'Negative term numbers not valid for Fibonacci Sequence', |
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355 | 'Provide a positive term number', |
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356 | 'A negative term number for the Fibonacci sequence was requested; provide a positive term number' |
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357 | ); |
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358 | } |
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359 | |||
360 | $fastFib = static::_fib($n); |
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361 | |||
362 | if ($asCollection) { |
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363 | $sequence = new NumberCollection(); |
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364 | $sequence->push($fastFib[0]); |
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365 | $sequence->push($fastFib[1]); |
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366 | for ($i = 0;$i < ($collectionSize-2);$i++) { |
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367 | $sequence->push($sequence->get($i)->add($sequence[$i+1])); |
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368 | } |
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369 | |||
370 | return $sequence; |
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371 | } |
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372 | |||
373 | return $fastFib[0]; |
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374 | } |
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375 | |||
376 | /** |
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377 | * OEIS: A000045 |
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378 | * |
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379 | * This uses an implementation of the fast-doubling Karatsuba multiplication algorithm as described by 'Nayuki': |
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380 | * |
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381 | * https://www.nayuki.io/page/fast-fibonacci-algorithms |
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382 | * |
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383 | * @param int $n |
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384 | * @return ImmutableDecimal[] |
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385 | * @throws IntegrityConstraint |
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386 | */ |
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387 | public static function nthFibonacciPair(int $n): array |
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388 | { |
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389 | $n = Numbers::makeOrDont(Numbers::IMMUTABLE, $n); |
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390 | |||
391 | if ($n->isLessThan(0)) { |
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392 | throw new IntegrityConstraint( |
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393 | 'Negative term numbers not valid for Fibonacci Sequence', |
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394 | 'Provide a positive term number', |
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395 | 'A negative term number for the Fibonacci sequence was requested; provide a positive term number' |
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396 | ); |
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397 | } |
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398 | |||
399 | return static::_fib($n); |
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400 | } |
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401 | |||
402 | /** |
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403 | * OEIS: A000032 |
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404 | * |
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405 | * @param int $n |
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406 | * @return ImmutableDecimal |
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407 | */ |
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408 | public static function nthLucasNumber(int $n): ImmutableDecimal |
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409 | { |
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410 | |||
411 | if ($n == 0) { |
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412 | return Numbers::make(Numbers::IMMUTABLE, 2); |
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413 | } elseif ($n == 1) { |
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414 | return Numbers::make(Numbers::IMMUTABLE, 1); |
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415 | } elseif ($n < 0) { |
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416 | throw new IntegrityConstraint( |
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417 | 'Negative term numbers not valid for Lucas Numbers', |
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418 | 'Provide a positive term number', |
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419 | 'A negative term number for the Lucas sequence was requested; provide a positive term number' |
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420 | ); |
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421 | } |
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422 | |||
423 | [$F1, $fib] = static::_fib(Numbers::make(Numbers::IMMUTABLE, $n-1)); |
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424 | [$fib, $F2] = static::_fib($fib); |
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425 | |||
426 | return $F1->add($F2); |
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427 | |||
428 | } |
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429 | |||
430 | /** |
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431 | * OEIS: A000217 |
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432 | * |
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433 | * @param int $n |
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434 | * @return ImmutableDecimal |
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435 | * @throws IntegrityConstraint |
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436 | */ |
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437 | public static function nthTriangularNumber(int $n): ImmutableDecimal |
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451 | |||
452 | } |
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453 | |||
454 | /** |
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455 | * @param ImmutableDecimal $number |
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456 | * @return ImmutableDecimal[] |
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457 | * @throws IntegrityConstraint |
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458 | */ |
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459 | private static function _fib(ImmutableDecimal $number): array |
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480 | } |
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481 | |||
482 | private static function _nextprime(ImmutableDecimal $number): ImmutableDecimal |
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483 | { |
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485 | } |
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486 | |||
487 | } |