#NEWLINE# def multi_stats( self , start , end , series = None , fields = None , stats = None ) : #NEWLINE# #INDENT# "Perform cross multivariate statistics calculation of\nthis :class:`ColumnTS` and other *series*.\n\n:parameter start: the start date.\n:parameter start: the end date\n:parameter field: name of field to perform multivariate statistics.\n:parameter series: a list of two elements tuple containing the id of the\n    a :class:`columnTS` and a field name.\n:parameter stats: list of statistics to evaluate.\n    Default: ['covariance']\n" #NEWLINE# stats = ( stats or self . default_multi_stats ) #NEWLINE# start = self . pickler . dumps ( start ) #NEWLINE# end = self . pickler . dumps ( end ) #NEWLINE# backend = self . read_backend #NEWLINE# return backend . execute ( backend . structure ( self ) . multi_stats ( self , end , fields , series , stats ) , self . _stats )