Error and gamma functions

xtensor provides the following error and gamma functions for xexpressions:

Defined in xtensor/xmath.hpp

Warning

doxygenfunction: Cannot find function “erf” in doxygen xml output for project “xtensor” from directory: ../xml

Warning

doxygenfunction: Cannot find function “erfc” in doxygen xml output for project “xtensor” from directory: ../xml

Warning

doxygenfunction: Cannot find function “tgamma” in doxygen xml output for project “xtensor” from directory: ../xml

Warning

doxygenfunction: Cannot find function “lgamma” in doxygen xml output for project “xtensor” from directory: ../xml