  Starting from the parametric representation of a Feynman diagram, we obtain
it's well defined value in dimensional regularisation by changing the integrals
over parameters into contour integrals. That way we eventually arrive at a
representation consisting of well-defined compact integrals. The result is a
simple transformation of the integrand which gives the analytic continuation of
a wide class of Feynmanintegrals. The algorithm will especially be fit for
numerical calculation of general massive multi-loop integrals. An important
advantage of this method is that it allows us to calculate both infinite and
finite parts independently.
