# numpy.finfo¶

class `numpy.``finfo`(dtype)[source]

Machine limits for floating point types.

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.

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.

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