# #StackBounty: #pgfplots #pgfmath pgfplots: x vs x

### Bounty: 50

• This question is a follow-up to this question ("pgfplots: Strange Bump in tanh Function").
• Stefan Pinnow, who knows a thing or two about pgfplots, provided an answer that distinguished between addplot{tanh(x)}; and addplot{tanh(x)};(x vs x as the argument).
• In a comment, Stefan stated "My thought also was that tanh(x) is the same as tanh(x) but it seems that Lua "doesn’t like" "commands", i.e. <something>. But to my experience I never used x in addplot calls. Since this is easier to read and easier to type […]".
% use TeX as calculation engine