1 \chapter{Mathematical expressions
}
4 At several points within
\PyX{} mathematical expressions can be
5 provided in form of string parameters. They are evaluated by the
6 module
\verb|mathtree|. This module is not described futher in this
7 user manual, because it is considered to be a technical detail. We
8 just give a list of available operators, functions and predefined
9 variable names here here.
13 \verb|+|;
\verb|-|;
\verb|*|;
\verb|/|;
\verb|**| and
\verb|^| (both
16 \verb|neg| (negate);
\verb|sgn| (signum);
\verb|sqrt| (square root);
17 \verb|exp|;
\verb|log| (natural logarithm);
\verb|sin|,
\verb|cos|,
18 \verb|tan|,
\verb|asin|,
\verb|acos|,
\verb|atan| (trigonometric
19 functions in radian units);
\verb|sind|,
\verb|cosd|,
\verb|tand|,
20 \verb|asind|,
\verb|acosd|,
\verb|atand| (as before but in degree
21 units);
\verb|norm| ($
\sqrt{a^
2+b^
2}$ as an example for functions with
23 \item[predefined variables:
]
24 \verb|pi| ($
\pi$);
\verb|e| ($e$)
