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phprating

constrain proportions between intervals

i'm trying to make a small class in php that would be used to integrate a rating system and i'm stuck on a little probably simple problem. i want to show the rating between 0 and 5 but the votes can be in any interval like 1 to 10 or 1 to 12. for example if interval was of votes was 1-12 and total score/total votes would be 6 i want to actually display 2.5 i'm currently using this 

$rating = number_format(round(($total_score/$total_votes)*2)/2,1);

so how can i make this to show values only 0-5 interval ?

Solution 
  • $fromminrate = 1;
$frommaxrate = 12;
$tominrate = 0;
$tomaxrate = 5;
$rating = $tominrate + (
     ((($total_score/$total_votes)-$fromminrate)
     / ($frommaxrate-$fromminrate))
     * ($tomaxrate-$tominrate));