torch.set_default_dtype
torch.set_default_dtype(d)
Sets the default floating point dtype to "d". Supports
   torch.float32 and torch.float64 as inputs. Other dtypes may be
   accepted without complaint but are not supported and are unlikely
   to work as expected.
When PyTorch is initialized its default floating point dtype is
   torch.float32, and the intent of set_default_dtype(torch.float64)
   is to facilitate NumPy-like type inference. The default floating
   point dtype is used to:


Implicitly determine the default complex dtype. When the default
      floating point type is float32 the default complex dtype is
      complex64, and when the default floating point type is float64
      the default complex type is complex128.


Infer the dtype for tensors constructed using Python floats or
      complex Python numbers. See examples below.


Determine the result of type promotion between bool and integer

