  A recursive algebraic method which allows to obtain the Feynman or Schwinger
parametric representation of a generic L-loops and (E+1) external lines
diagram, in a scalar $\phi ^{3}\oplus \phi ^{4}$ theory, is presented. The
representation is obtained starting from an Initial Parameters Matrix (IPM),
which relates the scalar products between internal and external momenta, and
which appears explicitly when this parametrization is applied to the momentum
space representation of the graph. The final product is an algorithm that can
be easily programmed, either in a computer programming language (C/C++,
Fortran,...) or in a symbolic calculation package (Maple, Mathematica,...).
