[Help-gsl] Is there a way to change the step size used by the (multi)root finder?

[Huaiyu Duan]

If the step size of the (multi)root finder is too big, it can enter
the region where the function is undefined (e.g., sqrt(-1)). I tried
having the function return the out of range error (GSL_EDOM), and the
iteration failed with the bad function error (GSL_EBADFUNC). I then
tried changing the solver's step size by manipulating solver->dx which
actually did not affect the step size. Is there a way to change the
step size used by the root finder? Thanks!