createfeature

//Stop-words
static const char * sw[] = {
    "a", "about", "an", "and", "are", "as", "at",
    "be", "by",
    "en",
    "for", "from",
    "how",
    "i", "in", "is", "it",
    "of", "on", "or",
    "that", "the", "this", "to",
    "was", "what", "when", "where", "which", "who", "why", "will", "with"
};

static Xapian::QueryParser
initialise_queryparser(const Xapian::Database & db)
{
    Xapian::SimpleStopper* mystopper;
    mystopper = new Xapian::SimpleStopper(sw, sw + sizeof(sw) / sizeof(sw[0]));
    Xapian::Stem stemmer("english");
    Xapian::QueryParser parser;
    parser.add_prefix("title", "S");
    parser.add_prefix("subject", "S");
    parser.set_database(db);
    parser.set_default_op(Xapian::Query::OP_OR);
    parser.set_stemmer(stemmer);
    parser.set_stemming_strategy(Xapian::QueryParser::STEM_SOME);
    parser.set_stopper(mystopper->release());
    return parser;
}


DEFINE_TESTCASE(createfeaturevector, generated)
{
    Xapian::FeatureList fl;
    string db_path = get_database_path("apitest_ranker1",
                       db_index_two_documents);
    Xapian::Enquire enquire((Xapian::Database(db_path)));
    Xapian::MSet mset;
    vector<Xapian::FeatureVector> fv =
        fl.create_feature_vectors(mset, Xapian::Query("lions"), (Xapian::Database(db_path)));
    TEST(fv.empty());
    string querystr = "lions";
    Xapian::QueryParser parser = initialise_queryparser( (Xapian::Database(db_path)));
    Xapian::Query query_no_prefix = parser.parse_query(querystr,
                    parser.FLAG_DEFAULT|
                    parser.FLAG_SPELLING_CORRECTION);
    // query with 'title' field as default prefix "S"
    Xapian::Query query_default_prefix = parser.parse_query(querystr,
                     parser.FLAG_DEFAULT|
                     parser.FLAG_SPELLING_CORRECTION,
                     "S");
    Xapian::Query query = Xapian::Query(Xapian::Query::OP_OR, query_no_prefix, query_default_prefix);
    enquire.set_query(query);
    mset = enquire.get_mset(0, 10);
    fv = fl.create_feature_vectors(mset, query,  (Xapian::Database(db_path)));
    for(size_t i =0;i<2;i++)
    {
    for(size_t j =0;j<19;j++)
    {
        printf("%f ",fv[i].get_fvals()[j]);
    }
    printf("\n");
    }
    return true;
}