<?php

namespace MathPHP\Statistics\Regression;

abstract class ParametricRegression extends Regression
{
    /**
     * An array of model parameters
     */
    protected $parameters;

    /**
     * Have the parent separate the points into xs and ys.
     * Calculate the regression parameters
     *
     * @param float[] $points
     */
    public function __construct(array $points)
    {
        parent::__construct($points);
        $this->calculate();
    }

    abstract public function calculate();
    
    /**
     * Return the model as a string
     */
    public function __toString(): string
    {
        return $this->getEquation();
    }

    /**
     * Get the equation
     * Uses the model's getModelEquation method.
     *
     * @return string
     */
    public function getEquation(): string
    {
        return $this->getModelEquation($this->parameters);
    }

    /**
     * Get the parameters
     * Uses the model's getModelParameters method.
     *
     * @return array
     */
    public function getParameters(): array
    {
        return $this->getModelParameters($this->parameters);
    }

    abstract public function getModelEquation(array $parameters): string;

    abstract public function getModelParameters(array $parameters): array;
}