Starting variable-order Adams and BDF codes (Q579860)

The paper presents a description and a discussion, not the listing, of a new procedure - named FINDH - for the automatic computation of an initial step size in the Euler or backward Euler integration scheme. This procedure can be applied in the usual variable-order codes for the numerical solution of initial value problems in ordinary differential equations. The construction of the initial stepsize is based on comparing the numerical values obtained by the Euler scheme and an explicit second order Runge-Kutta scheme. The results of many comparing tests are reported.