numpy.finfo¶

class
numpy.
finfo
(dtype)[source]¶ Machine limits for floating point types.
 Parameters
 dtypefloat, dtype, or instance
Kind of floating point datatype about which to get information.
See also
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 IEEE754 standard [1], NumPy floating point types make use of subnormal numbers to fill the gap between 0 andtiny
. However, subnormal numbers may have significantly reduced precision [2].References
 1
IEEE Standard for FloatingPoint Arithmetic, IEEE Std 7542008, pp.170, 2008, http://www.doi.org/10.1109/IEEESTD.2008.4610935
 2
Wikipedia, “Denormal Numbers”, https://en.wikipedia.org/wiki/Denormal_number
 Attributes
 bitsint
The number of bits occupied by the type.
 epsfloat
The difference between 1.0 and the next smallest representable float larger than 1.0. For example, for 64bit binary floats in the IEEE754 standard,
eps = 2**52
, approximately 2.22e16. epsnegfloat
The difference between 1.0 and the next smallest representable float less than 1.0. For example, for 64bit binary floats in the IEEE754 standard,
epsneg = 2**53
, approximately 1.11e16. iexpint
The number of bits in the exponent portion of the floating point representation.
 macharMachAr
The object which calculated these parameters and holds more detailed information.
 machepint
The exponent that yields eps.
 maxfloating point number of the appropriate type
The largest representable number.
 maxexpint
The smallest positive power of the base (2) that causes overflow.
 minfloating point number of the appropriate type
The smallest representable number, typically
max
. minexpint
The most negative power of the base (2) consistent with there being no leading 0’s in the mantissa.
 negepint
The exponent that yields epsneg.
 nexpint
The number of bits in the exponent including its sign and bias.
 nmantint
The number of bits in the mantissa.
 precisionint
The approximate number of decimal digits to which this kind of float is precise.
 resolutionfloating point number of the appropriate type
The approximate decimal resolution of this type, i.e.,
10**precision
. tinyfloat
The smallest positive floating point number with full precision (see Notes).