xtensor provides the following exponential functions for xexpressions:
Defined in xtensor/core/xmath.hpp
.. doxygenfunction:: exp(E&&)
.. doxygenfunction:: exp2(E&&)
.. doxygenfunction:: expm1(E&&)
.. doxygenfunction:: log(E&&)
.. doxygenfunction:: log2(E&&)
.. doxygenfunction:: log10(E&&)
.. doxygenfunction:: log1p(E&&)