好的，所以我有一系列值，如下所示:SymbolTimestampVolumePriceOpenNIF2011-05-1011:26:014397571.31501.3100NIF2011-05-1011:25:014397571.31501.3100NIF2011-05-1011:24:014397571.31501.3100NIF2011-05-1011:23:014397521.31501.3100NIF2011-05-1011:22:024397521.31501.3100NIF2011-05-1011:21:024397521.31501.3100NIF2011-05-1011