def studentized_residuals(self, p=None):
self._massage_data()<EOL>return self._studentized_residuals_fast(p)<EOL>
Massages the data and calculates the studentized residuals for 
each data set / function.

Parameters
----------
p=None
    List of parameter values for the functions. If None, it will use
    the fit results or guess values (if no fit results exist).