Type Info

The numerical properties of a torch.dtype can be accessed through either the torch.finfo or the torch.iinfo.

torch.finfo

class torch.finfo

A torch.finfo is an object that represents the numerical properties of a floating point torch.dtype, (i.e. torch.float32, torch.float64, torch.float16, and torch.bfloat16). This is similar to numpy.finfo.

A torch.finfo provides the following attributes:

Name	Type	Description
bits	int	The number of bits occupied by the type.
eps	float	The smallest representable number such that 1.0 + eps != 1.0.
max	float	The largest representable number.
min	float	The smallest representable number (typically -max).
tiny	float	The smallest positive normal number. Equivalent to smallest_normal.
smallest_normal	float	The smallest positive normal number. See notes.
resolution	float	The approximate decimal resolution of this type, i.e., 10**-precision.

Note

The constructor of torch.finfo can be called without argument, in which case the class is created for the pytorch default dtype (as returned by torch.get_default_dtype()).

Note

smallest_normal returns the smallest normal number, but there are smaller subnormal numbers. See https://en.wikipedia.org/wiki/Denormal_number for more information.

torch.iinfo

class torch.iinfo

A torch.iinfo is an object that represents the numerical properties of a integer torch.dtype (i.e. torch.uint8, torch.int8, torch.int16, torch.int32, and torch.int64). This is similar to numpy.iinfo.

A torch.iinfo provides the following attributes:

Name	Type	Description
bits	int	The number of bits occupied by the type.
max	int	The largest representable number.
min	int	The smallest representable number.