solr/contrib/ltr/src/test-files/modelExamples/external_model.json

{
    "class":"org.apache.solr.ltr.model.LinearModel",
    "name":"externalmodel",
    "features":[
        { "name": "titlePhraseMatch"}
    ],
    "params":{
        "weights": {
            "titlePhraseMatch": 0.555
        }
    }
}