math.expm1() - math

Return e**x - 1.  For small floats x, the subtraction in exp(x) - 1
can result in a significant loss of precision; the expm1()
function provides a way to compute this quantity to full precision:

Syntax

math.expm1(x)

Example

>>> from math import exp, expm1
>>> exp(1e-5) - 1  # gives result accurate to 11 places
1.0000050000069649e-05
>>> expm1(1e-5)    # result accurate to full precision
1.0000050000166668e-05

Output / Return Value

Limitations

Alternatives / See Also

Reference