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Diffstat (limited to 'numpy/doc/basics.py')
| -rw-r--r-- | numpy/doc/basics.py | 184 |
1 files changed, 151 insertions, 33 deletions
diff --git a/numpy/doc/basics.py b/numpy/doc/basics.py index 4d3ab046e..c87a40ccd 100644 --- a/numpy/doc/basics.py +++ b/numpy/doc/basics.py @@ -9,39 +9,157 @@ Array types and conversions between types NumPy supports a much greater variety of numerical types than Python does. This section shows which are available, and how to modify an array's data-type. -============ ========================================================== -Data type Description -============ ========================================================== -``bool_`` Boolean (True or False) stored as a byte -``int_`` Default integer type (same as C ``long``; normally either - ``int64`` or ``int32``) -intc Identical to C ``int`` (normally ``int32`` or ``int64``) -intp Integer used for indexing (same as C ``ssize_t``; normally - either ``int32`` or ``int64``) -int8 Byte (-128 to 127) -int16 Integer (-32768 to 32767) -int32 Integer (-2147483648 to 2147483647) -int64 Integer (-9223372036854775808 to 9223372036854775807) -uint8 Unsigned integer (0 to 255) -uint16 Unsigned integer (0 to 65535) -uint32 Unsigned integer (0 to 4294967295) -uint64 Unsigned integer (0 to 18446744073709551615) -``float_`` Shorthand for ``float64``. -float16 Half precision float: sign bit, 5 bits exponent, - 10 bits mantissa -float32 Single precision float: sign bit, 8 bits exponent, - 23 bits mantissa -float64 Double precision float: sign bit, 11 bits exponent, - 52 bits mantissa -``complex_`` Shorthand for ``complex128``. -complex64 Complex number, represented by two 32-bit floats (real - and imaginary components) -complex128 Complex number, represented by two 64-bit floats (real - and imaginary components) -============ ========================================================== - -Additionally to ``intc`` the platform dependent C integer types ``short``, -``long``, ``longlong`` and their unsigned versions are defined. +The primitive types supported are tied closely to those in C: + +.. list-table:: + :header-rows: 1 + + * - Numpy type + - C type + - Description + + * - `np.bool` + - ``bool`` + - Boolean (True or False) stored as a byte + + * - `np.byte` + - ``signed char`` + - Platform-defined + + * - `np.ubyte` + - ``unsigned char`` + - Platform-defined + + * - `np.short` + - ``short`` + - Platform-defined + + * - `np.ushort` + - ``unsigned short`` + - Platform-defined + + * - `np.intc` + - ``int`` + - Platform-defined + + * - `np.uintc` + - ``unsigned int`` + - Platform-defined + + * - `np.int_` + - ``long`` + - Platform-defined + + * - `np.uint` + - ``unsigned long`` + - Platform-defined + + * - `np.longlong` + - ``long long`` + - Platform-defined + + * - `np.ulonglong` + - ``unsigned long long`` + - Platform-defined + + * - `np.half` / `np.float16` + - + - Half precision float: + sign bit, 5 bits exponent, 10 bits mantissa + + * - `np.single` + - ``float`` + - Platform-defined single precision float: + typically sign bit, 8 bits exponent, 23 bits mantissa + + * - `np.double` + - ``double`` + - Platform-defined double precision float: + typically sign bit, 11 bits exponent, 52 bits mantissa. + + * - `np.longdouble` + - ``long double`` + - Platform-defined extended-precision float + + * - `np.csingle` + - ``float complex`` + - Complex number, represented by two single-precision floats (real and imaginary components) + + * - `np.cdouble` + - ``double complex`` + - Complex number, represented by two double-precision floats (real and imaginary components). + + * - `np.clongdouble` + - ``long double complex`` + - Complex number, represented by two extended-precision floats (real and imaginary components). + + +Since many of these have platform-dependent definitions, a set of fixed-size +aliases are provided: + +.. list-table:: + :header-rows: 1 + + * - Numpy type + - C type + - Description + + * - `np.int8` + - ``int8_t`` + - Byte (-128 to 127) + + * - `np.int16` + - ``int16_t`` + - Integer (-32768 to 32767) + + * - `np.int32` + - ``int32_t`` + - Integer (-2147483648 to 2147483647) + + * - `np.int64` + - ``int64_t`` + - Integer (-9223372036854775808 to 9223372036854775807) + + * - `np.uint8` + - ``uint8_t`` + - Unsigned integer (0 to 255) + + * - `np.uint16` + - ``uint16_t`` + - Unsigned integer (0 to 65535) + + * - `np.uint32` + - ``uint32_t`` + - Unsigned integer (0 to 4294967295) + + * - `np.uint64` + - ``uint64_t`` + - Unsigned integer (0 to 18446744073709551615) + + * - `np.intp` + - ``intptr_t`` + - Integer used for indexing, typically the same as ``ssize_t`` + + * - `np.uintp` + - ``uintptr_t`` + - Integer large enough to hold a pointer + + * - `np.float32` + - ``float`` + - + + * - `np.float64` / `np.float_` + - ``double`` + - Note that this matches the precision of the builtin python `float`. + + * - `np.complex64` + - ``float complex`` + - Complex number, represented by two 32-bit floats (real and imaginary components) + + * - `np.complex128` / `np.complex_` + - ``double complex`` + - Note that this matches the precision of the builtin python `complex`. + NumPy numerical types are instances of ``dtype`` (data-type) objects, each having unique characteristics. Once you have imported NumPy using |