You can't *see* 65,000 points, let alone 2 million.
If you subset the data in an external program Excel will happily plot graphs
far more detailed than would possibly be useful. If you want to use some of
Excels advanced features this may not work, but for display purposes it's
fine. As long as the data varies slowly relative to your sampling rate (ie
you obey Mr Nyquist's warnings) then you could just take every Nth data
point or process it intelligently. If the data varies "rapidly" then you can
only view a subset of it in a manner that is meaningful to your eye/brain.
Even plotted along the long side of an A3 sheet a 65000 point data set gives
about 4000 dpi !

        RM

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