[R] Calculate daily means from 5-minute interval data

[Rich Shepard]

On Tue, 31 Aug 2021, Richard O'Keefe wrote:

> I made up fake data in order to avoid showing untested code. It's not part
> of the process I was recommending. I expect data recorded every N minutes
> to use NA when something is missing, not to simply not be recorded. Well
> and good, all that means is that reshaping the data is not a trivial call
> to matrix(). It does not mean that any additional package is needed or
> appropriate and it does not affect the rest of the process.

Richard,

The instruments in the gauge pipe don't know to write NA when they're not
measuring. :-) The outage period varies greatly by location, constituent
measured, and other unknown factors.

> You will want the POSIXct class, see ?DateTimeClasses. Do you know whether
> the time stamps are in universal time or in local time?

The data values are not timestamps. There's one column for date a second
colume for time and a third column for time zone (P in the case of the west
coast.

> Above all, it doesn't affect the point that you probably should not
> be doing any of this.

? (Doesn't require an explanation.)

Rich