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HDF5 Predefined Datatypes

The following datatypes are predefined in HDF5.

Predefined IEEE Floating Point Datatypes
Datatype	Description
H5T_IEEE_F16BE	16-bit big-endian IEEE floating point
H5T_IEEE_F16LE	16-bit little-endian IEEE floating point
H5T_IEEE_F32BE	32-bit big-endian IEEE floating point
H5T_IEEE_F32LE	32-bit little-endian IEEE floating point
H5T_IEEE_F64BE	64-bit big-endian IEEE floating point
H5T_IEEE_F64LE	64-bit little-endian IEEE floating point

Predefined Alternative Floating Point Datatypes
Datatype	Description
H5T_FLOAT_BFLOAT16BE	16-bit big-endian bfloat16 floating point
H5T_FLOAT_BFLOAT16LE	16-bit little-endian bfloat16 floating point
H5T_FLOAT_F8E4M3	8-bit FP8 E4M3 (4 exponent bits, 3 mantissa bits) floating point
H5T_FLOAT_F8E5M2	8-bit FP8 E5M2 (5 exponent bits, 2 mantissa bits) floating point

Predefined Complex Number Datatypes
Datatype	Description
H5T_COMPLEX_IEEE_F16BE	Complex number of 2 16-bit big-endian IEEE floating point numbers
H5T_COMPLEX_IEEE_F16LE	Complex number of 2 16-bit little-endian IEEE floating point numbers
H5T_COMPLEX_IEEE_F32BE	Complex number of 2 32-bit big-endian IEEE floating point numbers
H5T_COMPLEX_IEEE_F32LE	Complex number of 2 32-bit little-endian IEEE floating point numbers
H5T_COMPLEX_IEEE_F64BE	Complex number of 2 64-bit big-endian IEEE floating point numbers
H5T_COMPLEX_IEEE_F64LE	Complex number of 2 64-bit little-endian IEEE floating point numbers

Predefined Standard Datatypes
Datatype	Description
H5T_STD_I8BE	8-bit big-endian signed integer (2's complement)
H5T_STD_I8LE	8-bit little-endian signed integer (2's complement)
H5T_STD_I16BE	16-bit big-endian signed integer (2's complement)
H5T_STD_I16LE	16-bit little-endian signed integer (2's complement)
H5T_STD_I32BE	32-bit big-endian signed integer (2's complement)
H5T_STD_I32LE	32-bit little-endian signed integer (2's complement)
H5T_STD_I64BE	64-bit big-endian signed integer (2's complement)
H5T_STD_I64LE	64-bit little-endian signed integer (2's complement)
H5T_STD_U8BE	8-bit big-endian unsigned integer
H5T_STD_U8LE	8-bit little-endian unsigned integer
H5T_STD_U16BE	16-bit big-endian unsigned integer
H5T_STD_U16LE	16-bit little-endian unsigned integer
H5T_STD_U32BE	32-bit big-endian unsigned integer
H5T_STD_U32LE	32-bit little-endian unsigned integer
H5T_STD_U64BE	64-bit big-endian unsigned integer
H5T_STD_U64LE	64-bit little-endian unsigned integer
H5T_STD_B8BE	8-bit big-endian bitfield
H5T_STD_B8LE	8-bit little-endian bitfield
H5T_STD_B16BE	16-bit big-endian bitfield
H5T_STD_B16LE	16-bit little-endian bitfield
H5T_STD_B32BE	32-bit big-endian bitfield
H5T_STD_B32LE	32-bit little-endian bitfield
H5T_STD_B64BE	64-bit big-endian bitfield
H5T_STD_B64LE	64-bit little-endian bitfield
H5T_STD_REF_OBJ	Object reference
H5T_STD_REF_DSETREG	Dataset region reference
H5T_STD_REF	Generic reference

Predefined UNIX-specific Datatypes
Datatype	Description
H5T_UNIX_D32BE	32-bit big-endian
H5T_UNIX_D32LE	32-bit little-endian
H5T_UNIX_D64BE	64-bit big-endian
H5T_UNIX_D64LE	64-bit little-endian

Predefined String Datatypes
Datatype	Description
H5T_C_S1	String datatype in C (size defined in bytes rather than in bits)
H5T_FORTRAN_S1	String datatype in Fortran (as defined for the HDF5 C library)

Predefined Intel-specific Datatypes
Datatype	Description
H5T_INTEL_I8	8-bit little-endian signed integer (2's complement)
H5T_INTEL_I16	16-bit little-endian signed integer (2's complement)
H5T_INTEL_I32	32-bit little-endian signed integer (2's complement)
H5T_INTEL_I64	64-bit little-endian signed integer (2's complement)
H5T_INTEL_U8	8-bit little-endian unsigned integer
H5T_INTEL_U16	16-bit little-endian unsigned integer
H5T_INTEL_U32	32-bit little-endian unsigned integer
H5T_INTEL_U64	64-bit little-endian unsigned integer
H5T_INTEL_B8	8-bit little-endian bitfield
H5T_INTEL_B16	16-bit little-endian bitfield
H5T_INTEL_B32	32-bit little-endian bitfield
H5T_INTEL_B64	64-bit little-endian bitfield
H5T_INTEL_F32	32-bit little-endian IEEE floating point
H5T_INTEL_F64	64-bit little-endian IEEE floating point

Predefined DEC Alpha-specific Datatypes
Datatype	Description
H5T_ALPHA_I8	8-bit little-endian signed integer (2's complement)
H5T_ALPHA_I16	16-bit little-endian signed integer (2's complement)
H5T_ALPHA_I32	32-bit little-endian signed integer (2's complement)
H5T_ALPHA_I64	64-bit little-endian signed integer (2's complement)
H5T_ALPHA_U8	8-bit little-endian unsigned integer
H5T_ALPHA_U16	16-bit little-endian unsigned integer
H5T_ALPHA_U32	32-bit little-endian unsigned integer
H5T_ALPHA_U64	64-bit little-endian unsigned integer
H5T_ALPHA_B8	8-bit little-endian bitfield
H5T_ALPHA_B16	16-bit little-endian bitfield
H5T_ALPHA_B32	32-bit little-endian bitfield
H5T_ALPHA_B64	64-bit little-endian bitfield
H5T_ALPHA_F32	32-bit little-endian IEEE floating point
H5T_ALPHA_F64	64-bit little-endian IEEE floating point

Predefined MIPS-specific Datatypes
Datatype	Description
H5T_MIPS_I8	8-bit big-endian signed integer (2's complement)
H5T_MIPS_I16	16-bit big-endian signed integer (2's complement)
H5T_MIPS_I32	32-bit big-endian signed integer (2's complement)
H5T_MIPS_I64	64-bit big-endian signed integer (2's complement)
H5T_MIPS_U8	8-bit big-endian unsigned integer
H5T_MIPS_U16	16-bit big-endian unsigned integer
H5T_MIPS_U32	32-bit big-endian unsigned integer
H5T_MIPS_U64	64-bit big-endian unsigned integer
H5T_MIPS_B8	8-bit big-endian bitfield
H5T_MIPS_B16	16-bit big-endian bitfield
H5T_MIPS_B32	32-bit big-endian bitfield
H5T_MIPS_B64	64-bit big-endian bitfield
H5T_MIPS_F32	32-bit big-endian IEEE floating point
H5T_MIPS_F64	64-bit big-endian IEEE floating point

Predefined Native Datatypes
Datatype	Description
H5T_NATIVE_CHAR	C-style char
H5T_NATIVE_SCHAR	C-style signed char
H5T_NATIVE_UCHAR	C-style unsigned signed char
H5T_NATIVE_SHORT	C-style short
H5T_NATIVE_USHORT	C-style unsigned short
H5T_NATIVE_INT	C-style int
H5T_NATIVE_UINT	C-style unsigned int
H5T_NATIVE_LONG	C-style long
H5T_NATIVE_ULONG	C-style unsigned long
H5T_NATIVE_LLONG	C-style long long
H5T_NATIVE_ULLONG	C-style unsigned long long
H5T_NATIVE_FLOAT16	C-style _Float16 (May be H5I_INVALID_HID if platform doesn't support _Float16 type)
H5T_NATIVE_FLOAT	C-style float
H5T_NATIVE_DOUBLE	C-style double
H5T_NATIVE_LDOUBLE	C-style long double
H5T_NATIVE_FLOAT_COMPLEX	C-style float _Complex (MSVC _Fcomplex) (May be H5I_INVALID_HID if platform doesn't support float _Complex / _Fcomplex type)
H5T_NATIVE_DOUBLE_COMPLEX	C-style double _Complex (MSVC _Dcomplex) (May be H5I_INVALID_HID if platform doesn't support double _Complex / _Dcomplex type)
H5T_NATIVE_LDOUBLE_COMPLEX	C-style long double _Complex (MSVC _Lcomplex) (May be H5I_INVALID_HID if platform doesn't support long double _Complex / _Lcomplex type)
H5T_NATIVE_B8	8-bit bitfield based on native types
H5T_NATIVE_B16	16-bit bitfield based on native types
H5T_NATIVE_B32	32-bit bitfield based on native types
H5T_NATIVE_B64	64-bit bitfield based on native types
H5T_NATIVE_OPAQUE	opaque unit based on native types
H5T_NATIVE_HADDR	address type based on native types
H5T_NATIVE_HSIZE	size type based on native types
H5T_NATIVE_HSSIZE	signed size type based on native types
H5T_NATIVE_HERR	error code type based on native types
H5T_NATIVE_HBOOL	Boolean type based on native types

Predefined ANSI C9x-specific Native Integer Datatypes
Datatype	Description
H5T_NATIVE_INT8	8-bit signed integer (2's complement)
H5T_NATIVE_UINT8	8-bit unsigned integer
H5T_NATIVE_INT_LEAST8	8-bit signed integer (2's complement) with storage to use least amount of space
H5T_NATIVE_UINT_LEAST8	8-bit unsigned integer with storage to use least amount of space
H5T_NATIVE_INT_FAST8	8-bit signed integer (2's complement) with storage to maximize performance
H5T_NATIVE_UINT_FAST8	8-bit unsigned integer with storage to maximize performance
H5T_NATIVE_INT16	16-bit signed integer (2's complement)
H5T_NATIVE_UINT16	16-bit unsigned integer
H5T_NATIVE_INT_LEAST16	16-bit signed integer (2's complement) with storage to use least amount of space
H5T_NATIVE_UINT_LEAST16	16-bit unsigned integer with storage to use least amount of space
H5T_NATIVE_INT_FAST16	16-bit signed integer (2's complement) with storage to maximize performance
H5T_NATIVE_UINT_FAST16	16-bit unsigned integer with storage to maximize performance
H5T_NATIVE_INT32	32-bit signed integer (2's complement)
H5T_NATIVE_UINT32	32-bit unsigned integer
H5T_NATIVE_INT_LEAST32	32-bit signed integer (2's complement) with storage to use least amount of space
H5T_NATIVE_UINT_LEAST32	32-bit unsigned integer with storage to use least amount of space
H5T_NATIVE_INT_FAST32	32-bit signed integer (2's complement) with storage to maximize performance
H5T_NATIVE_UINT_FAST32	32-bit unsigned integer with storage to maximize performance
H5T_NATIVE_INT64	64-bit signed integer (2's complement)
H5T_NATIVE_UINT64	64-bit unsigned integer
H5T_NATIVE_INT_LEAST64	64-bit signed integer (2's complement) with storage to use least amount of space
H5T_NATIVE_UINT_LEAST64	64-bit unsigned integer with storage to use least amount of space
H5T_NATIVE_INT_FAST64	64-bit signed integer (2's complement) with storage to maximize performance
H5T_NATIVE_UINT_FAST64	64-bit unsigned integer with storage to maximize performance

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