numpy.finfo

class numpy.finfo[源代码]

Machine limits for floating point types.

Parameters:
dtype : float, dtype, or instance

Kind of floating point data-type about which to get information.

参见

MachAr
The implementation of the tests that produce this information.
iinfo
The equivalent for integer data types.

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.

Attributes:
bits : int

The number of bits occupied by the type.

eps : float

The smallest representable positive number such that 1.0 + eps != 1.0. Type of eps is an appropriate floating point type.

epsneg : floating point number of the appropriate type

The smallest representable positive number such that 1.0 - epsneg != 1.0.

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 usable number. Type of tiny is an appropriate floating point type.