Resets the Gaussian Process.
ogpreset;
ogpreset resets the GLOBAL Gaussian Process structure net to its
original state.
If elements can be added to the BV set, then the BV set itself is cleared,
otherwise (ie. if net.isBVfixed~=0) the BV set is kept but other
Gaussian Process parameters in net are set to zero. One can use this
function to reset the OGP if kernel parameters change.
If there exists a nonempty GLOBAL structure ep, then the fields in
this structure are also reset to a default value.
Copyright (c) Lehel Csató (2001-2004)