[Numpy-discussion] Mapping of dtype to C types

[Pauli Virtanen]

Sun, 08 May 2011 14:45:45 -0700, Keith Goodman wrote:
> I'm writing a function that accepts four possible dtypes: int32, int64,
> float32, float64. The function will call a C extension (wrapped in
> Cython). What are the equivalent C types? int, long, float, double,
> respectively? Will that work on all systems?

Long can be 32-bit or 64-bit, depending on the platform.

The types available in Numpy are listed here, including
the information which of them are compatible with which C types:

http://docs.scipy.org/doc/numpy/reference/arrays.scalars.html

The C long seems not to be listed -- but it's the same as
"Python int", i.e., np.int_ will work.

IIRC, the Numpy type codes, dtype.kind, map directly to C types.

	Pauli