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Diffstat (limited to 'doc/source/reference/c-api.array.rst')
| -rw-r--r-- | doc/source/reference/c-api.array.rst | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/doc/source/reference/c-api.array.rst b/doc/source/reference/c-api.array.rst index 9265b1a97..d8c1dae97 100644 --- a/doc/source/reference/c-api.array.rst +++ b/doc/source/reference/c-api.array.rst @@ -202,7 +202,8 @@ From scratch PyTypeObject* subtype, PyArray_Descr* descr, int nd, npy_intp* dims, \ npy_intp* strides, void* data, int flags, PyObject* obj) - This function steals a reference to *descr*. + This function steals a reference to *descr*. The easiest way to get one + is using :c:func:`PyArray_DescrFromType`. This is the main array creation function. Most new arrays are created with this flexible function. @@ -216,9 +217,11 @@ From scratch :c:data:`&PyArray_Type<PyArray_Type>`, then *obj* is the object to pass to the :obj:`~numpy.class.__array_finalize__` method of the subclass. - If *data* is ``NULL``, then new memory will be allocated and *flags* - can be non-zero to indicate a Fortran-style contiguous array. If - *data* is not ``NULL``, then it is assumed to point to the memory + If *data* is ``NULL``, then new unitinialized memory will be allocated and + *flags* can be non-zero to indicate a Fortran-style contiguous array. Use + :c:ref:`PyArray_FILLWBYTE` to initialze the memory. + + If *data* is not ``NULL``, then it is assumed to point to the memory to be used for the array and the *flags* argument is used as the new flags for the array (except the state of :c:data:`NPY_OWNDATA`, :c:data:`NPY_ARRAY_WRITEBACKIFCOPY` and :c:data:`NPY_ARRAY_UPDATEIFCOPY` @@ -232,6 +235,12 @@ From scratch provided *dims* and *strides* are copied into newly allocated dimension and strides arrays for the new array object. + :c:func:`PyArray_CheckStrides` can help verify non- ``NULL`` stride + information. + + If ``data`` is provided, it must stay alive for the life of the array. One + way to manage this is through :c:func:`PyArray_SetBaseObject` + .. c:function:: PyObject* PyArray_NewLikeArray( \ PyArrayObject* prototype, NPY_ORDER order, PyArray_Descr* descr, \ int subok) @@ -2849,7 +2858,10 @@ Data-type descriptors Returns a data-type object corresponding to *typenum*. The *typenum* can be one of the enumerated types, a character code for - one of the enumerated types, or a user-defined type. + one of the enumerated types, or a user-defined type. If you want to use a + flexible size array, then you need to ``flexible typenum`` and set the + results ``elsize`` parameter to the desired size. The typenum is one of the + :c:data:`NPY_TYPES`. .. c:function:: int PyArray_DescrConverter(PyObject* obj, PyArray_Descr** dtype) |