Module « numpy »

Classe « finfo »

Informations générales

Héritage

builtins.object
    finfo

Définition

class finfo(builtins.object):

Description _{[extrait de finfo.__doc__]}

    finfo(dtype)

    Machine limits for floating point types.

    Attributes
    ----------
    bits : int
        The number of bits occupied by the type.
    eps : float
        The difference between 1.0 and the next smallest representable float
        larger than 1.0. For example, for 64-bit binary floats in the IEEE-754
        standard, ``eps = 2**-52``, approximately 2.22e-16.
    epsneg : float
        The difference between 1.0 and the next smallest representable float
        less than 1.0. For example, for 64-bit binary floats in the IEEE-754
        standard, ``epsneg = 2**-53``, approximately 1.11e-16.
    iexp : int
        The number of bits in the exponent portion of the floating point
        representation.
    machar : MachAr
        The object which calculated these parameters and holds more
        detailed information.
    machep : int
        The exponent that yields `eps`.
    max : floating point number of the appropriate type
        The largest representable number.
    maxexp : int
        The smallest positive power of the base (2) that causes overflow.
    min : floating point number of the appropriate type
        The smallest representable number, typically ``-max``.
    minexp : int
        The most negative power of the base (2) consistent with there
        being no leading 0's in the mantissa.
    negep : int
        The exponent that yields `epsneg`.
    nexp : int
        The number of bits in the exponent including its sign and bias.
    nmant : int
        The number of bits in the mantissa.
    precision : int
        The approximate number of decimal digits to which this kind of
        float is precise.
    resolution : floating point number of the appropriate type
        The approximate decimal resolution of this type, i.e.,
        ``10**-precision``.
    tiny : float
        The smallest positive floating point number with full precision
        (see Notes).

    Parameters
    ----------
    dtype : float, dtype, or instance
        Kind of floating point data-type about which to get information.

    See Also
    --------
    MachAr : The implementation of the tests that produce this information.
    iinfo : The equivalent for integer data types.
    spacing : The distance between a value and the nearest adjacent number
    nextafter : The next floating point value after x1 towards x2

    Notes
    -----
    For developers of NumPy: do not instantiate this at the module level.
    The initial calculation of these parameters is expensive and negatively
    impacts import times.  These objects are cached, so calling ``finfo()``
    repeatedly inside your functions is not a problem.

    Note that ``tiny`` is not actually the smallest positive representable
    value in a NumPy floating point type. As in the IEEE-754 standard [1]_,
    NumPy floating point types make use of subnormal numbers to fill the
    gap between 0 and ``tiny``. However, subnormal numbers may have
    significantly reduced precision [2]_.
    
    References
    ----------
    .. [1] IEEE Standard for Floating-Point Arithmetic, IEEE Std 754-2008,
           pp.1-70, 2008, http://www.doi.org/10.1109/IEEESTD.2008.4610935
    .. [2] Wikipedia, "Denormal Numbers",
           https://en.wikipedia.org/wiki/Denormal_number
    

Constructeur(s)

Signature du constructeur	Description
__new__(cls, dtype)

Liste des opérateurs

Opérateurs hérités de la classe object

__eq__, __ge__, __gt__, __le__, __lt__, __ne__

Méthodes héritées de la classe object

__delattr__, __dir__, __format__, __getattribute__, __hash__, __init_subclass__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __subclasshook__