This function gsl_multiroot_function_fdf requires three function entries: the basic function, the derivative of the function and a sequential call to the first two.
The operation of *_fdf (last function listed in gsl_multiroot_function_fdf) is clear in that a sequence of a call to the function followed by a derivative call guarantees that elements of the computation of the basic function may be carried over to the derivative call. What is not clear, because of the independently passed derivative call, is whether it is guarantee that the basic function will always be called (with the same arguments) before the derivative funtion. If this sequence were true, it would appear that the second function (derivative) argument in gsl_multiroot_function_fdf would not be necessary. What I am concerned with is: can I depend upon a call to the basic function prior to a call to the derivative function---each with the same vector x argument. Comments appreciated. Thank-you. PS: Current usage works assuming without carrying over computations but some speed up should occur if I can use previously computed elements in the derivatives. -- The whole religious complexion of the modern world is due to the absence from Jerusalem of a lunatic asylum. -- Havelock Ellis (1859-1939) British psychologist _______________________________________________ Help-gsl mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gsl
