fimedinet/escudero

<?php

namespace FimediNET\Escudero\Tools\BMR\Formulas;



/*
 * Calculator for Basal Metabolic Rate based on
 * Harris Benedict revised Roza Shizgal formula.
 *
 * Metric calculation.
 *
 * W: Weight (Kg)
 * H: Height (cm)
 * A: Age (years old)
 * 
 */
class BMRHarrisBenedictRevisedRS implements BMRFormulaInterface
{
    const GENDER_MALE = 'M';
    const GENDER_FEMALE = 'F';

    protected $formulas = [
        self::GENDER_MALE   => '88.362 + (13.397 * W) + (4.799 * H) - (5.677 * A)',
        self::GENDER_FEMALE => '447.593 + (9.247 * W) + (3.098 * H) - (4.330 * A)',
    ];

    public function expression(string $gender)
    {
        return $this->formulas[$gender];
    }

    public function formulaName() : string
    {
        return 'Harris Benedict revised by Roza Shizgal.';
    }
}