Elasticsearch - sort by the sum of elements within an array

sort_array.bash

#!/bin/bash

#delete the test type
curl -XDELETE localhost:9200/test/test2/

#insert some docs######
curl -XPOST localhost:9200/test/test2/ -d '{
    "id": 123,
    "a": 10,
    "b": 12,
    "c": [
        {
            "x": "A",
            "y": 102,
            "z": 92
        },
        {
            "x": "B",
            "y": 110,
            "z": 96
        }
    ]
}'

curl -XPOST localhost:9200/test/test2/ -d '{
    "id": 123,
    "a": 10,
    "b": 12,
    "c": [
        {
            "x": "A",
            "y": 10,
            "z": 92
        },
        {
            "x": "B",
            "y": 110,
            "z": 96
        }
    ]
}'

curl -XPOST localhost:9200/test/test2/ -d '{
    "id": 123,
    "a": 10,
    "b": 12,
    "c": [
        {
            "x": "A",
            "y": 1,
            "z": 92
        },
        {
            "x": "B",
            "y": 110,
            "z": 96
        }
    ]
}'
#done inserting######

#verify the mapping
curl localhost:9200/test/test2/_mapping

#refresh
curl localhost:9200/test/_refresh

#custom score query
curl localhost:9200/test/test2/_search?pretty=true -d '{
    "query": {
        "custom_score": {
            "query": {"match_all": {}},
            "script": "result=0; for (element : _source.c) { result = result + element.y; result = result + element.z*3 }; result"
        }
    }
}'

#script sort
curl localhost:9200/test/test2/_search?pretty=true -d '{
    "sort": {
        "_script": {
            "type": "number",
            "script": "result=0; for (element : _source.c) { result = result + element.y; result = result + element.z*3 }; result"
        }
    }
}'