During the computation of a curve it is sometimes necessary to
introduce variables and do additional computations that are common to all points of the
curve. The continuer has stored the handle to the initialization and cleaning of the workspace in the variables cds.curve_init and cds.curve_done.
These can be relegated to a call of the type
feval(cds.curve_init,x,v).
This option has to be provided only
if the variable WorkSpace in cds.options is switched on. In this case a call
feval(cds.curve_done,x,v)
must clear the workspace. Variables in the workspace must be set global.