Matching a closest number

Question

I have a series of numbers from 0 to 59 which are listed to a given step value. For example if I have Step value is 5 then the series become.

0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55

(or if the Step was 3, it'd become 0, 3, 6, 9, 12 .... 59 etc etc)

Now I need to find the closest match on a given user number. For example, if I the user number 18,19 or 20 then the closest match is 20. If the user number is 16,17 then it's 15. I am assuming this examples for step value of 5. But if it could be for any step value, then that would be great.

How do I do that?

$step = 5; 
$usernumber = 18;
$myseries = range(0, 59, $step);
foreach($myseries as $num) {
  echo $num.'<br />';

  //if($usernumber is close to $num) { 
  //      echo 'Matching number is '.$num;
  //}
}

Is step value will be fix ? Who will decide step value ? how it will going to change ? — Rikesh, Feb 24 '14 at 11:21
yes it will be fixed ... e.g. $step = 5; Updated code above. — user1421214, Feb 24 '14 at 11:25
Than see this question I guess is the same what you need..http://stackoverflow.com/questions/5464919/php-nearest-value-from-an-array — Rikesh, Feb 24 '14 at 11:26

score 3 · Accepted Answer · answered Feb 24 '14 at 11:29

3

What about $step * round($usernumber / $step) ?

You will need to check bounds of $usernumber and give it as a floating-point number for the division.

answered Feb 24 '14 at 11:29

Kiwi

2,698
16
15

Great - looks like this is what I need. Let me test. – user1421214 Feb 24 '14 at 11:32
1

this smashes any loop attempt, smart – Feb 24 '14 at 11:33

score 0 · Answer 2 · answered Feb 24 '14 at 11:31

0

try this

$step = 5; 
$usernumber = 188;
$myseries = range(0, 59, $step);

$myseries = range(0, 59, 5);

$check = round($usernumber/$step) * $step;

if(in_array($check,$myseries))
    echo "<br>".$check;
else
    echo max($myseries);

Demo

answered Feb 24 '14 at 11:31

krishna

4,069
2
29
56

score 0 · Answer 3 · answered Feb 24 '14 at 11:32

If your series won't have any holes (like 8, 9, 11), then you don't need to iterate through the whole array. It is only a draft, so not sure if it's 100% correct, but I hope it can help:

$usernumber = 18;
$min = 0;
$max = 60;
$step = 5;

$r = $usernumber % $step;
if ($r > $step / 2) {
    $num = $usernumber + ($step - $r);
    if ($num > $max) {
        $num = $max - $max % $step;
    }
}
else {
    $num = $usernumber - ($step - $r);
    if ($num < $min) {
        $num = $min + $step - ($min % $step);
    }
}
echo $num;

Matching a closest number

3 Answers3