pybind11/tests/test_numpy_vectorize.cpp
Jason Rhinelander f3ce00eaed vectorize: pass-through of non-vectorizable args
This extends py::vectorize to automatically pass through
non-vectorizable arguments.  This removes the need for the documented
"explicitly exclude an argument" workaround.

Vectorization now applies to arithmetic, std::complex, and POD types,
passed as plain value or by const lvalue reference (previously only
pass-by-value types were supported).  Non-const lvalue references and
any other types are passed through as-is.

Functions with rvalue reference arguments (whether vectorizable or not)
are explicitly prohibited: an rvalue reference is inherently not
something that can be passed multiple times and is thus unsuitable to
being in a vectorized function.

The vectorize returned value is also now more sensitive to inputs:
previously it would return by value when all inputs are of size 1; this
is now amended to having all inputs of size 1 *and* 0 dimensions.  Thus
if you pass in, for example, [[1]], you get back a 1x1, 2D array, while
previously you got back just the resulting single value.

Vectorization of member function specializations is now also supported
via `py::vectorize(&Class::method)`; this required passthrough support
for the initial object pointer on the wrapping function pointer.
2017-05-24 20:43:41 -04:00

86 lines
3.4 KiB
C++

/*
tests/test_numpy_vectorize.cpp -- auto-vectorize functions over NumPy array
arguments
Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#include "pybind11_tests.h"
#include <pybind11/numpy.h>
double my_func(int x, float y, double z) {
py::print("my_func(x:int={}, y:float={:.0f}, z:float={:.0f})"_s.format(x, y, z));
return (float) x*y*z;
}
std::complex<double> my_func3(std::complex<double> c) {
return c * std::complex<double>(2.f);
}
struct VectorizeTestClass {
VectorizeTestClass(int v) : value{v} {};
float method(int x, float y) { return y + (float) (x + value); }
int value = 0;
};
struct NonPODClass {
NonPODClass(int v) : value{v} {}
int value;
};
test_initializer numpy_vectorize([](py::module &m) {
// Vectorize all arguments of a function (though non-vector arguments are also allowed)
m.def("vectorized_func", py::vectorize(my_func));
// Vectorize a lambda function with a capture object (e.g. to exclude some arguments from the vectorization)
m.def("vectorized_func2",
[](py::array_t<int> x, py::array_t<float> y, float z) {
return py::vectorize([z](int x, float y) { return my_func(x, y, z); })(x, y);
}
);
// Vectorize a complex-valued function
m.def("vectorized_func3", py::vectorize(my_func3));
/// Numpy function which only accepts specific data types
m.def("selective_func", [](py::array_t<int, py::array::c_style>) { return "Int branch taken."; });
m.def("selective_func", [](py::array_t<float, py::array::c_style>) { return "Float branch taken."; });
m.def("selective_func", [](py::array_t<std::complex<float>, py::array::c_style>) { return "Complex float branch taken."; });
// Passthrough test: references and non-pod types should be automatically passed through (in the
// function definition below, only `b`, `d`, and `g` are vectorized):
py::class_<NonPODClass>(m, "NonPODClass").def(py::init<int>());
m.def("vec_passthrough", py::vectorize(
[](double *a, double b, py::array_t<double> c, const int &d, int &e, NonPODClass f, const double g) {
return *a + b + c.at(0) + d + e + f.value + g;
}
));
py::class_<VectorizeTestClass> vtc(m, "VectorizeTestClass");
vtc .def(py::init<int>())
.def_readwrite("value", &VectorizeTestClass::value);
// Automatic vectorizing of methods
vtc.def("method", py::vectorize(&VectorizeTestClass::method));
// Internal optimization test for whether the input is trivially broadcastable:
py::enum_<py::detail::broadcast_trivial>(m, "trivial")
.value("f_trivial", py::detail::broadcast_trivial::f_trivial)
.value("c_trivial", py::detail::broadcast_trivial::c_trivial)
.value("non_trivial", py::detail::broadcast_trivial::non_trivial);
m.def("vectorized_is_trivial", [](
py::array_t<int, py::array::forcecast> arg1,
py::array_t<float, py::array::forcecast> arg2,
py::array_t<double, py::array::forcecast> arg3
) {
ssize_t ndim;
std::vector<ssize_t> shape;
std::array<py::buffer_info, 3> buffers {{ arg1.request(), arg2.request(), arg3.request() }};
return py::detail::broadcast(buffers, ndim, shape);
});
});