Cadabra manual: Map

map_sympy

Map Sympy algorithms to Cadabra expressions

Cadabra expressions are typically tensor expressions, which you cannot feed directly into Sympy. With the map_sympy function you can recursively apply Sympy algorithms to the scalar parts of Cadabra expressions. The simplest example is when you have a scalar expression in Cadabra, for instance

ex:= \int{\sin(x)}{x};

\(\displaystyle{}\int \sin{x}\,\,{\rm d}x\)

map_sympy(ex);

\(\displaystyle{}-\cos{x}\)

The inert Cadabra expression gets evaluated by Sympy and then stored again in the `ex` object,

ex;

\(\displaystyle{}-\cos{x}\)

In more complicated cases you may have a tensorial expression which you would like to simplify using Sympy, for instance

ex:= (\sin(x)**2 + \cos(x)**2) A_{m} - A_{m};

\(\displaystyle{}\left({\left(\sin{x}\right)}^{2}+{\left(\cos{x}\right)}^{2}\right) A_{m}-A_{m}\)

map_sympy(ex, "simplify");

\(\displaystyle{}0\)