[PHP-CLI] "Gradual" Condorcet

<?php

// download php on : https://www.php.net/downloads.php

// each vote will be stocked within a single .csv file.
// for example, if you have a proposition "prop1", and vote :
   // 24% on fuck no
   // 30% on meh
   // 47% on okay
   // 50% on good
   // 68% on pretty good
   // 98% on hell yeah
// then you'll have a line in "prop1.csv" where it's written :
   // 24,30,47,50,68,98

// each vote will be stocked in arrays, which look like :
   /* [24,30,47,50,68,98] */
// with each being percentages for, from left-to-right :
   // fuck no
   // meh
   // okay
   // good
   // pretty good
   // hell yeah

function csv2arr ($path) {
/* description */
 // converts a csv file's content in a 2d array (table),
 // csv files being big tables of data separated by commas.
/* use */
 // we'll stock votes from prop1.csv to propn.csv for n=2, or 3, ...
 // we'll have to convert them into 2d arrays (tables) to use them.
/* parameter(s) */
 // $path
    // path of the csv file.
    // here it's just "1.csv", "2.csv", etc.
    // that's bcs they're all in the same folder as this program.

    $file = file($path);
    // file($path) creates an array with each line,
    //  and $file = file($path); assigns the array of
    //  file($path) to $file.
    // however, right now it's still not very usable,
    //  because it thinks these are just big strings
    //  of characters with lots of commas in there.
    // we therefore need to convert those strings
    //  into arrays, which is what we'll do here :

    foreach ($file as $index => $eval) {
    // foreach ($path as $index => $eval) runs through the $file array,
    //  and at each step it assigns the index to $index and the string
    //  content to $eval (which i called like that bcs they'll have to
    //  be evaluated).
        eval("\$ret[$index] = [$eval];");
        // in those csv files, there are just numbers.
        // in php, we can define an array $array of numbers as such :
           /* $array = [24,30,47,50,68,98]; */
        // eval() evaluates the expression within the input, and if,
        //  for example, $eval = "24,30,47,50,68,98", then "[$eval]"
        //  which will be evaluated as :
           /* [24,30,47,50,68,98] */
        // hence, "\$ret[$index] = [$eval];" will assign the evaluated
        //  array eval("[$eval]") to $ret[$index]. in this example,
        //  it will assign [24,30,47,50,68,98] to $ret[$index].
    }

    return $ret;
    // the resulting array of arrays / 2d array / table will be returned
    //  by the function. so for example, if we have :
       /* $ret[0] = [24,30,47,50,68,98] */
    //  we can then reach the first value, 24, doing $ret[0][0], the
    //  second with $ret[0][1], the third with $ret[0][2], etc.

}

$dir = scandir(".");
// takes all the files in the folder and puts their name and extension in
//  an array. if you put the csv files in a specific subfolder, replace "."
//  by the name of said folder in quotation marks.

foreach ($dir as $fileNameExt) {
// runs through each file, and assigns to $file the name and extension of
//  each file in the folder at each step.

    if (strpos($fileNameExt,".csv") !== false) {
    // if the file is a .csv file...

        $propositions[str_replace(".csv","",$fileNameExt)] = csv2arr($fileNameExt);
        // each proposition voting tables/.csv files will be assigned their
        //  .csv table converted into arrays, so we can actually use them.
        //  the str_replace(".csv","",$fileNameExt) removes the extension to
        //  $fileNameExt, which is basically just the file name then lol.

    }

}

function linear_interpolation ($array) {
/* description */
 // maps each percentage $array[0..5] to $ret[0], $ret[20], $ret[40],
 //  $ret[60], $ret[80], $ret[100], and use linear interpolation to fill
 //  in the gaps, and rounding all the values to the nearest integer.
 // basically the v function which was presented in the video.
/* use */
 // we will use it along with condorcet's method to determine the condorcet
 //  winning percentage which will be assigned to the proposition.
/* parameter(s) */
 // $array
    // one of the arrays from $propositions[..] tables.

    foreach ($array as $score => $percentage) {
    // runs through all the percentages and scores given.

        $ret[$score*20] = round($percentage);
        // maps each percentage $array[0..5] to $ret[0], $ret[20], $ret[40],
        //  $ret[60], $ret[80], $ret[100].

        if ($score < 5)
            for ($i = $score*20+1; $i < ($score+1)*20; $i++)
                $ret[$i] = round(($array[$score+1]-$percentage)
                                  * ($i-$score*20)/20
                                 + $percentage)+rand(-50,49)/100;
        // that's the linear interpolation part, we fill the gaps for indices
        //  other than 0, 20, 40, 60, 80 or 100, and rounds the values. the
        //  rand(-50,49)/100 value added gives a random value betwen -0.5 and
        //  +0.49 in order to randomly sort tying rounded values in (*).

    }

    return $ret;

}

// <minor function>
function array_of_indices (&$array) {

    $ret = [];
    foreach ($array as $index => $content)
        $ret[count($ret)] = $index;
    $array = $ret;

    // pretty self-explainatory

}
// </minor function>

foreach ($propositions as $fileName => $votes) {

    $preferences[$fileName] = [];

    foreach ($votes as $index => $vote) {

        for ($i = 0; $i < max($vote); $i++) {
        // we will count each vote as if it were as many votes as the maximum
        //  percentage of all the ones given in the vote.

            $tmp = linear_interpolation($vote);
            // we stock the array of this linearly interpolated vote temporarily.

            arsort($tmp); // (*)
            array_of_indices($tmp);
            $preferences[$fileName][count($preferences[$fileName])] = $tmp;

        }

    }

}

function maximal_lotteries ($votes) {
/* description */
 // we use condorcet's method first, aka we take each percentages on 1-to-1
 //  contests with each other and make an array of all the
/* use */
 // we will use it along with condorcet's method to determine the condorcet
 //  winning percentage which will be assigned to the proposition.
/* parameter(s) */
 // $votes
    // self-explainatory.

    foreach ($votes as $vote) {

        for ($percentage1 = 0; $percentage1 <= 100; $percentage1 += 1) {
                                                //                  |
                                                // you can give higher
                                                // values to faster, but
                                                // you will lose accuracy
                                                //                  |
        for ($percentage2 = 0; $percentage2 <= 100; $percentage2 += 1) {

            if ($percentage1 != $percentage2)
            $ranking[$percentage1] += intval(array_search($percentage1,$vote)
                                        <=   array_search($percentage2,$vote));

        }}

    }

    $condorcet = [];

    for ($percentage = 0; $percentage <= 100; $percentage++) {

        if (max($ranking) == $ranking[$percentage])
            $condorcet[count($condorcet)] = $percentage;

    }

    return $condorcet[rand(0,count($condorcet)-1)];

}

print "\n  Results (can take a while) :\n";

foreach ($preferences as $proposition => $votes) {

    print "   - $proposition : ".maximal_lotteries($votes)." %\n";
    // gives the final results

}
print "\n  If there is a tie, you can :
   - Run the program again
   - Pick a random winner in the ones with the highest percentage\n";

system("pause>nul");

?>