Type Info — PyTorch 2.7 documentation (original) (raw)

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 pointtorch.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()).

torch.iinfo

class torch.iinfo

A torch.iinfo is an object that represents the numerical properties of a integertorch.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.