painless script to sort by calculating Euclidean distance in elastic search 6.4

euclidean_distance_sort.json

//can be used with -> curl -XGET -H "Content-Type:application/json" http://es_host:es_port/image_index/_search -d@euclidean_distance_sort.json
{
  "sort" : {
    "_score" : "asc" 
  },
   
    "query": {
    "function_score" : {
      "script_score" : {
        "script" : {
          "lang" : "painless",
           "source":" int distance = 0;int max_score = 9363600 ; def docvalues = params._source['vec']; if(docvalues.length != params.query_feature.size()){ distance = max_score; }else{ int i=0;for(val in docvalues){int diff = (int)val - (int)(params.query_feature[i]); diff=(int)(Math.abs(diff)); distance = diff*diff; i += 1;}}return Math.sqrt(distance);"
                ,
                 "params" : {
                   "query_feature" : [ 555,1125,1116, 728, 292, ..omitted]
                } 
        }
      }
    }
  },
  "size":10,
  "from":"0"
}