Portable Document Format (PDF) - Institut für Mathematik - TU Berlin

The vector-valued functions of linear problems require implementation accordingto the following standards.• Headerfunction [f,ierr] = anyName(l, t, idif)ArgumentsThe following table describes the input arguments to the auxiliary function.ltidifnumber of equationstimeparameter specifying the order of desired derivative.The following table lists the output arguments for the auxiliary function.fierridif-th derivative of Gerror flag being always zerosonly if idif is larger than the highest derivativethat this function provides ierr is assigned the value −2.DescriptionThis function takes as input the number of equations m as well as the timet and the parameter idif. As output, it produces the idif-th derivative off at time t. An error is signaled via ierr if a higher derivative is requestedthan provided.The functions for nonlinear problems look a little bit different. It is shownbelow. In the following let µ be the strangeness-index of the DAE.• Headerfunction [F,ierr] = anyName(t, idif, x)ArgumentsThe following table describes the input arguments to the auxiliary function.tidifxtimeparameter specifying the order of desired derivativevector containing an approximation to the solution˜x = (x, ẋ, ..., x (m+1) ), where m ≥ µ.The following table lists the output arguments for the auxiliary function.Fierrcolumn vector containing the idif-th derivative of Ferror flag being always zerosonly if idif is larger than the highest derivativethat this function provides ierr is assigned the value −1.30