If you have a function defined in an external program, then what you need to do in order to make it possible to call the function from within Mathematica is to add ...
LQRegulatorGains[ss, {q, r}] gives the optimal state feedback gain matrix for the StateSpaceModel object ss and the quadratic cost function with state and control weighting ...
ZTransform[expr, n, z] gives the Z transform of expr. ZTransform[expr, {n_1, n_2, ...}, {z_1, z_2, ...}] gives the multidimensional Z transform of expr.
AdjacencyGraph[amat] gives the graph with adjacency matrix amat.AdjacencyGraph[{v_1, v_2, ...}, amat] gives the graph with vertices v_i and adjacency matrix amat.
IncidenceGraph[m] gives the graph with incidence matrix m.
KirchhoffGraph[kmat] gives the graph with Kirchhoff matrix kmat.KirchhoffGraph[{v_1, v_2, ...}, kmat] gives the graph with vertices v_i and Kirchhoff matrix kmat.
MomentConvert[mexpr, form] converts the moment expression mexpr to the specified form.
PathGraph[{v_1, v_2, ...}] yields a path with vertices v_i and edges between v_i and v i +\[ThinSpace]1 .PathGraph[{e_1, e_2, ...}] yields a path with edges ...
RSolve
(Built-in Mathematica Symbol) RSolve[eqn, a[n], n] solves a recurrence equation for a[n]. RSolve[{eqn_1, eqn_2, ...}, {a_1[n], a_2[n], ...}, n] solves a system of recurrence equations. RSolve[eqn, a[n_1, ...
WeightedAdjacencyGraph[wmat] gives the graph with weighted adjacency matrix wmat.WeightedAdjacencyGraph[{v_1, v_2, ...}, wmat] gives the graph with vertices v_i and weighted ...