$('.stars_small').raty({
                              readOnly : true,
                              half  : true,
                              score : 2,
                              space : false
                         });

<div class="stars_small"></div>

$('.stars_small').each(function() {

         $(this).raty({
                    readOnly : true,
                    half  : true,
                    score : 2,
                    space : false
              });
        });

// lines of JS generated with a loop in PHP (for the rate content)
var rates = [];
rates.push({...one rate coming from PHP...});
rates.push({...one rate coming from PHP...});
// etc...

$(document).ready(function() {

    $(".starts_small").each(function(index, element) {

        $(this).raty(rates[index]);

    });

});