mars.tensor.
expm1
Calculate exp(x) - 1 for all elements in the tensor.
exp(x) - 1
x (array_like) – Input values.
out (Tensor, None, or tuple of Tensor and None, optional) – A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated tensor is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.
where (array_like, optional) – Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone.
**kwargs –
out – Element-wise exponential minus one: out = exp(x) - 1.
out = exp(x) - 1
Tensor
See also
log1p
log(1 + x), the inverse of expm1.
log(1 + x)
Notes
This function provides greater precision than exp(x) - 1 for small values of x.
x
Examples
The true value of exp(1e-10) - 1 is 1.00000000005e-10 to about 32 significant digits. This example shows the superiority of expm1 in this case.
exp(1e-10) - 1
1.00000000005e-10
>>> import mars.tensor as mt
>>> mt.expm1(1e-10).execute() 1.00000000005e-10 >>> (mt.exp(1e-10) - 1).execute() 1.000000082740371e-10