in python/src/theta_wrapper.cpp [32:168]
void init_theta(py::module &m) {
using namespace datasketches;
py::class_<theta_sketch>(m, "theta_sketch")
.def("__str__", &theta_sketch::to_string, py::arg("print_items")=false,
"Produces a string summary of the sketch")
.def("to_string", &theta_sketch::to_string, py::arg("print_items")=false,
"Produces a string summary of the sketch")
.def("is_empty", &theta_sketch::is_empty,
"Returns True if the sketch is empty, otherwise False")
.def("get_estimate", &theta_sketch::get_estimate,
"Estimate of the distinct count of the input stream")
.def("get_upper_bound", &theta_sketch::get_upper_bound, py::arg("num_std_devs"),
"Returns an approximate upper bound on the estimate at standard deviations in {1, 2, 3}")
.def("get_lower_bound", &theta_sketch::get_lower_bound, py::arg("num_std_devs"),
"Returns an approximate lower bound on the estimate at standard deviations in {1, 2, 3}")
.def("is_estimation_mode", &theta_sketch::is_estimation_mode,
"Returns True if sketch is in estimation mode, otherwise False")
.def("get_theta", &theta_sketch::get_theta,
"Returns theta (effective sampling rate) as a fraction from 0 to 1")
.def("get_theta64", &theta_sketch::get_theta64,
"Returns theta as 64-bit value")
.def("get_num_retained", &theta_sketch::get_num_retained,
"Returns the number of items currently in the sketch")
.def("get_seed_hash", &theta_sketch::get_seed_hash,
"Returns a hash of the seed used in the sketch")
.def("is_ordered", &theta_sketch::is_ordered,
"Returns True if the sketch entries are sorted, otherwise False")
.def("__iter__", [](const theta_sketch& s) { return py::make_iterator(s.begin(), s.end()); })
;
py::class_<update_theta_sketch, theta_sketch>(m, "update_theta_sketch")
.def(
py::init([](uint8_t lg_k, double p, uint64_t seed) {
return update_theta_sketch::builder().set_lg_k(lg_k).set_p(p).set_seed(seed).build();
}),
py::arg("lg_k")=theta_constants::DEFAULT_LG_K, py::arg("p")=1.0, py::arg("seed")=DEFAULT_SEED
)
.def(py::init<const update_theta_sketch&>())
.def("update", (void (update_theta_sketch::*)(int64_t)) &update_theta_sketch::update, py::arg("datum"),
"Updates the sketch with the given integral value")
.def("update", (void (update_theta_sketch::*)(double)) &update_theta_sketch::update, py::arg("datum"),
"Updates the sketch with the given floating point value")
.def("update", (void (update_theta_sketch::*)(const std::string&)) &update_theta_sketch::update, py::arg("datum"),
"Updates the sketch with the given string")
.def("compact", &update_theta_sketch::compact, py::arg("ordered")=true,
"Returns a compacted form of the sketch, optionally sorting it")
.def("trim", &update_theta_sketch::trim, "Removes retained entries in excess of the nominal size k (if any)")
.def("reset", &update_theta_sketch::reset, "Resets the sketch to the initial empty state")
;
py::class_<compact_theta_sketch, theta_sketch>(m, "compact_theta_sketch")
.def(py::init<const compact_theta_sketch&>())
.def(py::init<const theta_sketch&, bool>())
.def(
"serialize",
[](const compact_theta_sketch& sk) {
auto bytes = sk.serialize();
return py::bytes(reinterpret_cast<const char*>(bytes.data()), bytes.size());
},
"Serializes the sketch into a bytes object"
)
.def_static(
"deserialize",
[](const std::string& bytes, uint64_t seed) {
return compact_theta_sketch::deserialize(bytes.data(), bytes.size(), seed);
},
py::arg("bytes"), py::arg("seed")=DEFAULT_SEED,
"Reads a bytes object and returns the corresponding compact_theta_sketch"
);
py::class_<theta_union>(m, "theta_union")
.def(
py::init([](uint8_t lg_k, double p, uint64_t seed) {
return theta_union::builder().set_lg_k(lg_k).set_p(p).set_seed(seed).build();
}),
py::arg("lg_k")=theta_constants::DEFAULT_LG_K, py::arg("p")=1.0, py::arg("seed")=DEFAULT_SEED
)
.def("update", &theta_union::update<const theta_sketch&>, py::arg("sketch"),
"Updates the union with the given sketch")
.def("get_result", &theta_union::get_result, py::arg("ordered")=true,
"Returns the sketch corresponding to the union result")
;
py::class_<theta_intersection>(m, "theta_intersection")
.def(py::init<uint64_t>(), py::arg("seed")=DEFAULT_SEED)
.def(py::init<const theta_intersection&>())
.def("update", &theta_intersection::update<const theta_sketch&>, py::arg("sketch"),
"Intersections the provided sketch with the current intersection state")
.def("get_result", &theta_intersection::get_result, py::arg("ordered")=true,
"Returns the sketch corresponding to the intersection result")
.def("has_result", &theta_intersection::has_result,
"Returns True if the intersection has a valid result, otherwise False")
;
py::class_<theta_a_not_b>(m, "theta_a_not_b")
.def(py::init<uint64_t>(), py::arg("seed")=DEFAULT_SEED)
.def(
"compute",
&theta_a_not_b::compute<const theta_sketch&, const theta_sketch&>,
py::arg("a"), py::arg("b"), py::arg("ordered")=true,
"Returns a sketch with the result of applying the A-not-B operation on the given inputs"
)
;
py::class_<theta_jaccard_similarity>(m, "theta_jaccard_similarity")
.def_static(
"jaccard",
[](const theta_sketch& sketch_a, const theta_sketch& sketch_b, uint64_t seed) {
return theta_jaccard_similarity::jaccard(sketch_a, sketch_b, seed);
},
py::arg("sketch_a"), py::arg("sketch_b"), py::arg("seed")=DEFAULT_SEED,
"Returns a list with {lower_bound, estimate, upper_bound} of the Jaccard similarity between sketches"
)
.def_static(
"exactly_equal",
&theta_jaccard_similarity::exactly_equal<const theta_sketch&, const theta_sketch&>,
py::arg("sketch_a"), py::arg("sketch_b"), py::arg("seed")=DEFAULT_SEED,
"Returns True if sketch_a and sketch_b are equivalent, otherwise False"
)
.def_static(
"similarity_test",
&theta_jaccard_similarity::similarity_test<const theta_sketch&, const theta_sketch&>,
py::arg("actual"), py::arg("expected"), py::arg("threshold"), py::arg("seed")=DEFAULT_SEED,
"Tests similarity of an actual sketch against an expected sketch. Computers the lower bound of the Jaccard "
"index J_{LB} of the actual and expected sketches. If J_{LB} >= threshold, then the sketches are considered "
"to be similar with a confidence of 97.7% and returns True, otherwise False.")
.def_static(
"dissimilarity_test",
&theta_jaccard_similarity::dissimilarity_test<const theta_sketch&, const theta_sketch&>,
py::arg("actual"), py::arg("expected"), py::arg("threshold"), py::arg("seed")=DEFAULT_SEED,
"Tests dissimilarity of an actual sketch against an expected sketch. Computers the lower bound of the Jaccard "
"index J_{UB} of the actual and expected sketches. If J_{UB} <= threshold, then the sketches are considered "
"to be dissimilar with a confidence of 97.7% and returns True, otherwise False."
)
;
}