PHP Find closest percentile for a numbered variable

Question

I have 3 percentile values calculated that are stored in variables like this:

$twentyfive = '55';
$fifty = '80';
$seventyfive = '95';

Each user on my website has a value from 20-100 stored in the variable: $percentile and I am trying to match their number closest to one of the three variables above so I can say: You are part of the X percentile.

For example, if a users $percentile value was '35' they would be matched with $twentyfive since that's the closest variable to their number.

Any help would be appreciated

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What will the range for giving the user these percentiles? Like $twentyfive : 20 to ?, $fifty : ? to ? So on — ShivCK, May 14 '19 at 18:41

score 0 · Answer 1 · edited May 14 '19 at 20:05

0

if($percentile < 67.5){
   echo $twentyfive
}  elseif($percentile > 67.5 && $percentile < 87.7){
   echo $fifty
}else{
   echo $seventyfive
}

edited May 14 '19 at 20:05

Valentino

7,291
6
18
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answered May 14 '19 at 18:41

Isuru Indika Lokuhelapitiya

1
1

if you dont want to hardcode values get the difference and devide it by 2 and add to the value – Isuru Indika Lokuhelapitiya May 14 '19 at 18:45

score 0 · Answer 2 · answered May 14 '19 at 18:48

If the values of the 3 variables can change you can use this. There may be a more concise way, but this should work.

//Set users percentile
$user_percentile = 35;
$user_percentile_category = 25;

switch ($user_percentile) {
    case $user_percentile <= $twentyfive:
        $user_percentile_category = '25';
        break;
    case ($user_percentile - $twentyfive) < $fifty - $user_percentile:
        $user_percentile_category = '25';
        break;
    case ($user_percentile - $twentyfive) >= $fifty - $user_percentile:
        $user_percentile_category = '50';
        break;
    case ($user_percentile - $fifty) < $seventyfive - $user_percentile:
        $user_percentile_category = '50';
        break;
    case ($user_percentile - $fifty) >= $seventyfive - $user_percentile:
        $user_percentile_category = '75';
        break;
    default:
        $user_percentile_category = '75';
}

score 0 · Answer 3 · answered May 14 '19 at 19:03

You can use below code for this:

function getClosest($search, $arr) {
   $closest = null;
   foreach ($arr as $item) {
      if ($closest === null || abs($search - $closest) > abs($item - $search)) {
         $closest = $item;
      }
   }
   return $closest;
}

$collection = [55,80,95];
$searchValue = 88;

echo getClosest($searchValue, $collection);

Hope it helps you. I have taken the reference from Find a matching or closest value in an array

Cheers!!

PHP Find closest percentile for a numbered variable

3 Answers3