jax.numpy.finfo#

classjax.numpy.finfo(dtype)#

Machine limits for floating point types.

bits#

The number of bits occupied by the type.

Type:

int

dtype#

Returns the dtype for whichfinfo returns information. For complexinput, the returned dtype is the associatedfloat* dtype for itsreal and complex components.

Type:

dtype

eps#

The difference between 1.0 and the next smallest representable floatlarger than 1.0. For example, for 64-bit binary floats in the IEEE-754standard,eps=2**-52, approximately 2.22e-16.

Type:

float

epsneg#

The difference between 1.0 and the next smallest representable floatless than 1.0. For example, for 64-bit binary floats in the IEEE-754standard,epsneg=2**-53, approximately 1.11e-16.

Type:

float

iexp#

The number of bits in the exponent portion of the floating pointrepresentation.

Type:

int

machep#

The exponent that yieldseps.

Type:

int

max#

The largest representable number.

Type:

floating point number of the appropriate type

maxexp#

The smallest positive power of the base (2) that causes overflow.

Type:

int

min#

The smallest representable number, typically-max.

Type:

floating point number of the appropriate type

minexp#

The most negative power of the base (2) consistent with therebeing no leading 0’s in the mantissa.

Type:

int

negep#

The exponent that yieldsepsneg.

Type:

int

nexp#

The number of bits in the exponent including its sign and bias.

Type:

int

nmant#

The number of bits in the mantissa.

Type:

int

precision#

The approximate number of decimal digits to which this kind offloat is precise.

Type:

int

resolution#

The approximate decimal resolution of this type, i.e.,10**-precision.

Type:

floating point number of the appropriate type

tiny#

An alias forsmallest_normal, kept for backwards compatibility.

Type:

float

smallest_normal#

The smallest positive floating point number with 1 as leading bit inthe mantissa following IEEE-754 (see Notes).

Type:

float

smallest_subnormal#

The smallest positive floating point number with 0 as leading bit inthe mantissa following IEEE-754.

Type:

float

Parameters:

dtype (float,dtype, orinstance) – Kind of floating point or complex floating pointdata-type about which to get information.

See also

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 negativelyimpacts import times. These objects are cached, so callingfinfo()repeatedly inside your functions is not a problem.

Note thatsmallest_normal is not actually the smallest positiverepresentable value in a NumPy floating point type. As in the IEEE-754standard[1], NumPy floating point types make use of subnormal numbers tofill the gap between 0 andsmallest_normal. However, subnormal numbersmay have significantly reduced precision[2].

This function can also be used for complex data types as well. If used,the output will be the same as the corresponding real float type(e.g. numpy.finfo(numpy.csingle) is the same as numpy.finfo(numpy.single)).However, the output is true for the real and imaginary components.

References

[1]

IEEE Standard for Floating-Point Arithmetic, IEEE Std 754-2008,pp.1-70, 2008,https://doi.org/10.1109/IEEESTD.2008.4610935

[2]

Wikipedia, “Denormal Numbers”,https://en.wikipedia.org/wiki/Denormal_number

Examples

>>>importnumpyasnp>>>np.finfo(np.float64).dtypedtype('float64')>>>np.finfo(np.complex64).dtypedtype('float32')

__init__()#

Methods

__init__()

Attributes

smallest_normal	Return the value for the smallest normal.
tiny	Return the value for tiny, alias of smallest_normal.