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<?php |
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|
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namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\Statistical; |
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|
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use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled; |
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use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception; |
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use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Functions; |
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use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError; |
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|
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class Confidence |
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{ |
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use ArrayEnabled; |
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|
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/** |
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* CONFIDENCE. |
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* |
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* Returns the confidence interval for a population mean |
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* |
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* @param mixed $alpha As a float |
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* Or can be an array of values |
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* @param mixed $stdDev Standard Deviation as a float |
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* Or can be an array of values |
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* @param mixed $size As an integer |
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* Or can be an array of values |
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* |
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* @return array<mixed>|float|string If an array of numbers is passed as an argument, then the returned result will also be an array |
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* with the same dimensions |
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*/ |
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public static function CONFIDENCE($alpha, $stdDev, $size) |
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{ |
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if (is_array($alpha) || is_array($stdDev) || is_array($size)) { |
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return self::evaluateArrayArguments([self::class, __FUNCTION__], $alpha, $stdDev, $size); |
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} |
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|
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try { |
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$alpha = StatisticalValidations::validateFloat($alpha); |
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$stdDev = StatisticalValidations::validateFloat($stdDev); |
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$size = StatisticalValidations::validateInt($size); |
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} catch (Exception $e) { |
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return $e->getMessage(); |
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} |
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|
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if (($alpha <= 0) || ($alpha >= 1) || ($stdDev <= 0) || ($size < 1)) { |
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return ExcelError::NAN(); |
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} |
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/** @var float $temp */ |
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$temp = Distributions\StandardNormal::inverse(1 - $alpha / 2); |
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|
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/** @var float */ |
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$result = Functions::scalar($temp * $stdDev / sqrt($size)); |
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|
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return $result; |
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} |
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} |
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