PHP - I'm Trying To Add An Email Auto Responder Into A Existing Php Script

Hello! I found this code from github. https://github.com/gburtini/Learning-Library-for-PHP and I want to know if its possible to add variables to it and what changes needed to be done to the whole script.
My first guess is the variables are 

$xs

and 

$ys

I want replace them and add two more. The whole code is he

<?php 

    require_once 'function.php';

    function ll_nn_predict($xs, $ys, $row, $k) {
        $distances = ll_nearestNeighbors($xs, $row);
        $distances = array_slice($distances, 0, $k);

        $predictions = array();
        foreach($distances as $neighbor=>$distance) {
            $predictions[$ys[$neighbor]]++;
        }
        asort($predictions);

        return $predictions;
    }

    function ll_nearestNeighbors($xs, $row) {
        $testPoint = $xs[$row];

        $distances = _ll_distances_to_point($xs, $testPoint);
        return $distances;
    }

    function _ll_distances_to_point($xs, $x) {
        $distances = array();
        foreach($xs as $index=>$xi) {
            $distances[$index] = ll_euclidean_distance($xi, $x);
        }
        asort($distances);
        array_shift($distances);
        return $distances;
    }

and the function.php that is required is this:

<?php

    function ll_transpose($rows) {
        $columns = array();
        for($i=0;$i<count($rows);$i++) {
            for($k = 0; $k<count($rows[$i]); $k++) {
                $columns[$k][$i] = $rows[$i][$k];
            }
        }
        return $columns;
    }

    function ll_mean($array) {
        return array_sum($array)/($array);
    }

    function ll_variance($array) {
        $mean = ll_mean($array);

        $sum_difference = 0;
        $n = count($array);

        for($i=0; $i<$n; $i++) {
            $sum_difference += pow(($array[$i] - $mean),2);
        }

        $variance = $sum_difference / $n;
        return $variance;
    }
 
    function ll_euclidean_distance($a, $b) {
        if(count($a) != count($b))
            return false;
        
        $distance = 0;
        for($i=0;$i<count($a);$i++) {
            $distance += pow($a[$i] - $b[$i], 2);
        }

        return sqrt($distance);
    }

 

I just want to know where is the variables in those 2 scripts and add more as I'm not well versed in using PHP. Thank you!

Is there anything different between a response and a responder?  My thought is maybe a response is something that one application gives to another, and a responder is used only by a single application to create a response.

interface TrendInterface
{
    public function getResponse($blabla):TrendResponse;
    public function getResponder($blabla):TrendResponder;
}

Hi,

In my attendance system i want to add email alert using php. I want the system to check the records in my db and send email to everyone that  forgot to clock-in after 7:30AM from Sunday to Thursday. What i need to use for this, ideas?