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<?php |
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declare(strict_types=1); |
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namespace ExtendedStrings\Strings; |
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class VibratingString |
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{ |
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private $frequency; |
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/** |
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* @param float $frequency |
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*/ |
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public function __construct(float $frequency) |
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{ |
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$this->frequency = $frequency; |
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} |
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/** |
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* @param float $stringLength |
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* |
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* @return float |
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*/ |
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View Code Duplication |
public function getStoppedFrequency(float $stringLength = 1.0): float |
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{ |
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if (Math::isZero($stringLength)) { |
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return 0; |
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} |
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$centsOverString = Cent::frequenciesToCents($stringLength, 1); |
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return Cent::centsToFrequency($centsOverString, $this->frequency); |
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} |
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/** |
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* @param float $stringLength |
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* |
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* @return float |
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*/ |
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public function getHarmonicSoundingFrequency(float $stringLength = 1.0): float |
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{ |
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return Math::isZero($stringLength) |
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? 0 |
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: $this->frequency * self::getHarmonicNumber($stringLength); |
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} |
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/** |
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* @param float $frequency |
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* |
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* @return float |
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*/ |
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View Code Duplication |
public function getStringLength(float $frequency): float |
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{ |
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if (Math::isZero($frequency)) { |
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return 0; |
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} |
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$centsOverString = Cent::frequenciesToCents($this->frequency, $frequency); |
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return $this->centsToStringLength($centsOverString); |
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} |
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/** |
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* @param float $cents |
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* The number of cents between the open string and the stop. |
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* |
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* @return float |
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* The length of the remaining vibrating string. |
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*/ |
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private function centsToStringLength(float $cents): float |
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{ |
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return 1 / pow(2, $cents / 1200); |
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} |
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/** |
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* @param float $stringLength |
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* |
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* @throws \InvalidArgumentException |
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* |
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* @return int |
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*/ |
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public static function getHarmonicNumber(float $stringLength): int |
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{ |
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$number = intval(1 / Math::gcd(1, $stringLength)); |
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if ($number > 100) { |
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throw new \InvalidArgumentException(sprintf('Invalid string length for a harmonic: %f', $stringLength)); |
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} |
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return $number; |
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} |
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/** |
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* @param int $limit |
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* |
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* @return float[] |
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*/ |
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public static function getHarmonicSeries(int $limit): array |
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{ |
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$series = []; |
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$base = 0; |
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for ($denominator = 1; $denominator <= $limit; $denominator++) { |
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$base = $series[$denominator] = $base + 1 / $denominator; |
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} |
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return $series; |
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} |
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} |
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extended-strings /
strings
