in src/theta_wrapper.cpp [35:197]
void init_theta(nb::module_ &m) {
using namespace datasketches;
nb::class_<theta_sketch>(m, "theta_sketch", "An abstract base class for theta sketches")
.def("__str__", [](const theta_sketch& sk) { return sk.to_string(); },
"Produces a string summary of the sketch")
.def("to_string", [](const theta_sketch& sk, bool print_items) { return sk.to_string(print_items); }, nb::arg("print_items")=false,
"Produces a string summary of the sketch")
.def("is_empty", static_cast<bool (theta_sketch::*)() const>(&theta_sketch::is_empty),
"Returns True if the sketch is empty, otherwise False")
.def("get_estimate", static_cast<double (theta_sketch::*)() const>(&theta_sketch::get_estimate),
"Estimate of the distinct count of the input stream")
.def("get_upper_bound", static_cast<double (theta_sketch::*)(uint8_t) const>(&theta_sketch::get_upper_bound), nb::arg("num_std_devs"),
"Returns an approximate upper bound on the estimate at standard deviations in {1, 2, 3}")
.def("get_lower_bound", static_cast<double (theta_sketch::*)(uint8_t) const>(&theta_sketch::get_lower_bound), nb::arg("num_std_devs"),
"Returns an approximate lower bound on the estimate at standard deviations in {1, 2, 3}")
.def("is_estimation_mode", static_cast<bool (theta_sketch::*)() const>(&theta_sketch::is_estimation_mode),
"Returns True if sketch is in estimation mode, otherwise False")
.def_prop_ro("theta", static_cast<double (theta_sketch::*)() const>(&theta_sketch::get_theta),
"Theta (effective sampling rate) as a fraction from 0 to 1")
.def_prop_ro("theta64", static_cast<uint64_t (theta_sketch::*)() const>(&theta_sketch::get_theta64),
"Theta as 64-bit value")
.def_prop_ro("num_retained", static_cast<uint32_t (theta_sketch::*)() const>(&theta_sketch::get_num_retained),
"The number of items currently in the sketch")
.def("get_seed_hash", static_cast<uint16_t (theta_sketch::*)() const>(&theta_sketch::get_seed_hash),
"Returns a hash of the seed used in the sketch")
.def("is_ordered", static_cast<bool (theta_sketch::*)() const>(&theta_sketch::is_ordered),
"Returns True if the sketch entries are sorted, otherwise False")
.def("__iter__",
[](const theta_sketch& s) {
return nb::make_iterator(nb::type<theta_sketch>(),
"theta_iterator",
s.begin(),
s.end());
}, nb::keep_alive<0,1>()
)
;
nb::class_<update_theta_sketch, theta_sketch>(m, "update_theta_sketch")
.def("__init__",
[](update_theta_sketch* sk, uint8_t lg_k, double p, uint64_t seed) {
new (sk) update_theta_sketch(update_theta_sketch::builder().set_lg_k(lg_k).set_p(p).set_seed(seed).build());
},
nb::arg("lg_k")=theta_constants::DEFAULT_LG_K, nb::arg("p")=1.0, nb::arg("seed")=DEFAULT_SEED,
"Creates an update_theta_sketch using the provided parameters\n\n"
":param lg_k: base 2 logarithm of the maximum size of the sketch. Default 12.\n:type lg_k: int, optional\n"
":param p: an initial sampling rate to use. Default 1.0\n:type p: float, optional\n"
":param seed: the seed to use when hashing values\n:type seed: int, optional\n"
)
.def("__copy__", [](const update_theta_sketch& sk){ return update_theta_sketch(sk); })
.def("update", (void (update_theta_sketch::*)(int64_t)) &update_theta_sketch::update, nb::arg("datum"),
"Updates the sketch with the given integral value")
.def("update", (void (update_theta_sketch::*)(double)) &update_theta_sketch::update, nb::arg("datum"),
"Updates the sketch with the given floating point value")
.def("update", (void (update_theta_sketch::*)(const std::string&)) &update_theta_sketch::update, nb::arg("datum"),
"Updates the sketch with the given string")
.def("compact", &update_theta_sketch::compact, nb::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")
;
nb::class_<compact_theta_sketch, theta_sketch>(m, "compact_theta_sketch")
.def(nb::init<const theta_sketch&, bool>(),
"Creates a compact_theta_sketch from an existing theta_sketch.\n\n"
":param other: a source theta_sketch\n:type other: theta_sketch\n"
":param ordered: whether the incoming sketch entries are sorted. Default True\n"
":type ordered: bool"
)
.def("__copy__", [](const compact_theta_sketch& sk){ return compact_theta_sketch(sk); })
.def(
"serialize",
[](const compact_theta_sketch& sk, bool compress) {
auto bytes = compress ? sk.serialize_compressed() : sk.serialize();
return nb::bytes(reinterpret_cast<const char*>(bytes.data()), bytes.size());
}, nb::arg("compress")=false,
"Serializes the sketch into a bytes object, optionally compressing the data"
)
.def_static(
"deserialize",
[](const nb::bytes& bytes, uint64_t seed) {
return compact_theta_sketch::deserialize(bytes.c_str(), bytes.size(), seed);
},
nb::arg("bytes"), nb::arg("seed")=DEFAULT_SEED,
"Reads a bytes object and returns the corresponding compact_theta_sketch"
);
nb::class_<theta_union>(m, "theta_union")
.def("__init__",
[](theta_union* u, uint8_t lg_k, double p, uint64_t seed) {
new (u) theta_union(theta_union::builder().set_lg_k(lg_k).set_p(p).set_seed(seed).build());
},
nb::arg("lg_k")=theta_constants::DEFAULT_LG_K, nb::arg("p")=1.0, nb::arg("seed")=DEFAULT_SEED,
"Creates a theta_union using the provided parameters\n\n"
":param lg_k: base 2 logarithm of the maximum size of the union. Default 12.\n:type lg_k: int, optional\n"
":param p: an initial sampling rate to use. Default 1.0\n:type p: float, optional\n"
":param seed: the seed to use when hashing values. Must match all sketch seeds.\n:type seed: int, optional"
)
.def("update", &theta_union::update<const theta_sketch&>, nb::arg("sketch"),
"Updates the union with the given sketch")
.def("get_result", &theta_union::get_result, nb::arg("ordered")=true,
"Returns the sketch corresponding to the union result")
;
nb::class_<theta_intersection>(m, "theta_intersection")
.def(nb::init<uint64_t>(), nb::arg("seed")=DEFAULT_SEED,
"Creates a theta_intersection using the provided parameters\n\n"
":param seed: the seed to use when hashing values. Must match all sketch seeds\n:type seed: int, optional"
)
.def("update", &theta_intersection::update<const theta_sketch&>, nb::arg("sketch"),
"Intersections the provided sketch with the current intersection state")
.def("get_result", &theta_intersection::get_result, nb::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")
;
nb::class_<theta_a_not_b>(m, "theta_a_not_b")
.def(nb::init<uint64_t>(), nb::arg("seed")=DEFAULT_SEED,
"Creates a tuple_a_not_b object\n\n"
":param seed: the seed to use when hashing values. Must match all sketch seeds.\n:type seed: int, optional"
)
.def(
"compute",
&theta_a_not_b::compute<const theta_sketch&, const theta_sketch&>,
nb::arg("a"), nb::arg("b"), nb::arg("ordered")=true,
"Returns a sketch with the result of applying the A-not-B operation on the given inputs"
)
;
nb::class_<theta_jaccard_similarity>(m, "theta_jaccard_similarity",
"An object to help compute Jaccard similarity between theta sketches.")
.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);
},
nb::arg("sketch_a"), nb::arg("sketch_b"), nb::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&>,
nb::arg("sketch_a"), nb::arg("sketch_b"), nb::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&>,
nb::arg("actual"), nb::arg("expected"), nb::arg("threshold"), nb::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&>,
nb::arg("actual"), nb::arg("expected"), nb::arg("threshold"), nb::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."
)
;
}