System configuration¶
When NumPy is built, information about system configuration is recorded, and is made available for extension modules using Numpy’s C API. These are mostly defined in numpyconfig.h (included in ndarrayobject.h). The public symbols are prefixed by NPY_*. Numpy also offers some functions for querying information about the platform in use.
For private use, Numpy also constructs a config.h in the NumPy include directory, which is not exported by Numpy (that is a python extension which use the numpy C API will not see those symbols), to avoid namespace pollution.
Data type sizes¶
The NPY_SIZEOF_{CTYPE} constants are defined so that sizeof information is available to the pre-processor.
- NPY_SIZEOF_SHORT¶
sizeof(short)
- NPY_SIZEOF_INT¶
sizeof(int)
- NPY_SIZEOF_LONG¶
sizeof(long)
- NPY_SIZEOF_LONG_LONG¶
sizeof(longlong) where longlong is defined appropriately on the platform (A macro defines NPY_SIZEOF_LONGLONG as well.)
- NPY_SIZEOF_PY_LONG_LONG¶
- NPY_SIZEOF_FLOAT¶
sizeof(float)
- NPY_SIZEOF_DOUBLE¶
sizeof(double)
- NPY_SIZEOF_LONG_DOUBLE¶
sizeof(longdouble) (A macro defines NPY_SIZEOF_LONGDOUBLE as well.)
- NPY_SIZEOF_PY_INTPTR_T¶
Size of a pointer on this platform (sizeof(void *)) (A macro defines NPY_SIZEOF_INTP as well.)
Platform information¶
- NPY_CPU_X86¶
- NPY_CPU_AMD64¶
- NPY_CPU_IA64¶
- NPY_CPU_PPC¶
- NPY_CPU_PPC64¶
- NPY_CPU_SPARC¶
- NPY_CPU_SPARC64¶
- NPY_CPU_S390¶
- NPY_CPU_PARISC¶
バージョン 1.3.0 で追加.
CPU architecture of the platform; only one of the above is defined.
Defined in numpy/npy_cpu.h
- NPY_LITTLE_ENDIAN¶
- NPY_BIG_ENDIAN¶
- NPY_BYTE_ORDER¶
バージョン 1.3.0 で追加.
Portable alternatives to the endian.h macros of GNU Libc. If big endian, NPY_BYTE_ORDER == NPY_BIG_ENDIAN, and similarly for little endian architectures.
Defined in numpy/npy_endian.h.
- PyArray_GetEndianness()¶
バージョン 1.3.0 で追加.
Returns the endianness of the current platform. One of NPY_CPU_BIG, NPY_CPU_LITTLE, or NPY_CPU_UNKNOWN_ENDIAN.