Required fixes

[chldkdtn]

Default values not properly declared

If the function takes a default value in its arguments, it needs to be specified with py::arg. For example of Vector constructor,

// Constructor
.def(py::init([](py::array_t<double> vec, bool distributed, bool copy_data = true) {
        py::buffer_info buf_info = vec.request();
        int dim = buf_info.shape[0];
        double* data = static_cast<double*>(buf_info.ptr);
        return new Vector(data, dim, distributed, copy_data);
    }), py::arg("vec"), py::arg("distributed"), py::arg("copy_data") = true) // default value needs to be defined here.

Note the last line.

Vector::getData not returning an array object

In c++, getData function returns the memory address of the data array. In python, this should return the reference of the data array. Currently, Vector::getData does not do any special care, returning a float value as a result.

.def("getData", &Vector::getData)

Vector::get_data naming

Compared to the function above, this function can cause a confusion. Based on its action, it needs to be renamed as copy_data or something.

(Enhancement) Vector and Matrix as a buffer protocol

Vector and Matrix should support buffer view, to handler large-size arrays without copying them in memory. Useful references are:

• python buffer protocol
• pybind11 numpy instruction

Based on pybind11 numpy instruction, an example of Matrix definition should be:

py::class_<Matrix>(m, "Matrix", py::buffer_protocol()) 
    .def_buffer([](Matrix &self) -> py::buffer_info {
        return py::buffer_info(
            self.getData(),                         /* Pointer to buffer */
            sizeof(float),                          /* Size of one scalar */
            py::format_descriptor<float>::format(), /* Python struct-style format descriptor */
            2,                                      /* Number of dimensions */
            { self.numRows(), self.numColumns() },  /* Buffer dimensions */
            { sizeof(float) * self.numColumns(),
              sizeof(float) }                       /* Strides (in bytes) for each index */
        );
    })

Similar definition is possible for Vector as well.

(Enhancement) Supporting slice view of Vector and Matrix

Vector and Matrix must support slice view of its data.