[R] Locating data source error in large file

[Rich Shepard]

On Fri, 20 Jul 2018, William Dunlap wrote:

> Which format did you use when you used is.na on the output of
>   as.POSIXlt(strings, format=someFormat)
> and found none?  Did the resulting dates look OK?  Perhaps
> all is well.

Bill,

   All dates here are kept as yyyy-mm-dd.

   And each dataframe row has this format:
2015-10-01,00:00,90.6689
2015-10-01,01:00,90.6506
2015-10-01,02:00,90.6719
2015-10-01,03:00,90.6506

Thanks,

Rich