PyArray_SimpleNewFromData example

Question

I know that this thing has been answered a lot of times and I have also read the documentation as well but still I am not able to clearly understand how is this working. As

Answer 1

Make sure that you plug the memory leak that the above approach entrails. I am guessing in the above x is a pointer of type void *. Check this out.

Answer 2

The function is:

 PyObject *
    PyArray_SimpleNewFromData(
        int nd, 
        npy_intp* dims, 
        int typenum, 
         void* data)

• The last argument (data) is a buffer to the data. Let's dispense with that.

• The second argument (dims) is a buffer, whose each entry is a dimension; so for a 1d array, it could be a length-1 buffer (or even an integer, since each integer is a length-1 buffer)

• Since the second argument is a buffer, the first argument (nd) tells its length

• The third argument (typenum) indicates the type.

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For example, say you have 4 64-bit ints at x:

To create an array, use

int dims[1];
dims[0] = 4;
PyArray_SimpleNewFromData(1, dims, NPY_INT64, x)

To create a 2X2 matrix, use

int dims[2];
dims[0] = dims[1] = 2;
PyArray_SimpleNewFromData(2, dims, NPY_INT64, x)