[R] Find tibble row with maximum recorded value

[Rich Shepard]

On Fri, 3 Dec 2021, Bert Gunter wrote:

> Perhaps you meant to point this out, but the cfs[which.max(cfs)] and
> cfs == ... are not the same:
>
>> x <- rep(1:2,3)
>> x
> [1] 1 2 1 2 1 2
>> x[which.max(x)]
> [1] 2
>> x[x==max(x)]
> [1] 2 2 2
>
> So maybe your point is: which does the OP want (in case there are
> repeated maxes)? I suspect the == forms, but ...?

Bert,

When I looked at the results I saw there were many rows with the maximum
(and minimum) values. I thought those represented instrument limits, and
they apparently do. For example, 99.9000 cubic feet per second is reached
multiple times over the past 32 years.

> max(pdx_disc$cfs)
[1] 99900

and

> filter(pdx_disc, cfs == max(cfs))
# A tibble: 74 × 9
    site_nbr  year   mon   day    hr   min tz      cfs sampdt
    <chr>    <int> <int> <int> <dbl> <dbl> <chr> <dbl> <dttm>
  1 14211720  1988    11    28     0     0 PST   99900 1988-11-28 00:00:00
  2 14211720  1988    11    28     5     0 PST   99900 1988-11-28 05:00:00
  3 14211720  1988    11    28     5    10 PST   99900 1988-11-28 05:10:00
  4 14211720  1988    11    28     5    20 PST   99900 1988-11-28 05:20:00
  5 14211720  1988    11    29     6    20 PST   99900 1988-11-29 06:20:00
  6 14211720  1988    11    29    13     0 PST   99900 1988-11-29 13:00:00
  7 14211720  1988    11    29    13    10 PST   99900 1988-11-29 13:10:00
  8 14211720  1988    11    29    15    20 PST   99900 1988-11-29 15:20:00
  9 14211720  1989     1    11     0     0 PST   99900 1989-01-11 00:00:00
10 14211720  1989     1    11     0    10 PST   99900 1989-01-11 00:10:00
# … with 64 more rows

So the gauge was pegged at its top end quite a few times over the years.
Makes me wonder just how much higher really was.

Carpe weekend,

Rich