R help - Dec 2021 - Find tibble row with maximum recorded value

On Fri, 3 Dec 2021, Rich Shepard wrote:
> I find solutions when the data_frame is grouped, but none when it's
not.
Thanks, Bert. ?which.max confirmed that's all I need to find the maximum
value.

Now I need to read more than ?filter to learn why I'm not getting the
relevant row with:
> which.max(pdx_disc$cfs)
[1] 8054
> filter(pdx_disc, cfs == 8054)
# A tibble: 0 ? 9
# ? with 9 variables: site_nbr <chr>, year <int>, mon <int>,
day <int>,
#   hr <dbl>, min <dbl>, tz <chr>, cfs <dbl>, sampdt
<dttm>

Regards,

Rich

Hello,

Inline.

?s 22:08 de 03/12/21, Rich Shepard escreveu:
> On Fri, 3 Dec 2021, Rich Shepard wrote:
> 
>> I find solutions when the data_frame is grouped, but none when it's
not.
> 
> Thanks, Bert. ?which.max confirmed that's all I need to find the
maximum
> value.
> 
> Now I need to read more than ?filter to learn why I'm not getting the
> relevant row with:
>> which.max(pdx_disc$cfs)
> [1] 8054
This is the *index* for which cfs is the first maximum, not the maximum 
value itself.
> 
>> filter(pdx_disc, cfs == 8054)
Therefore, you probably want any of


filter(pdx_disc, cfs == cfs[8054])

filter(pdx_disc, cfs == cfs[which.max(cfs)])

filter(pdx_disc, cfs == max(cfs))    # I find this one better, simpler


Hope this helps,

Rui Barradas

> # A tibble: 0 ? 9
> # ? with 9 variables: site_nbr <chr>, year <int>, mon
<int>, day <int>,
> #?? hr <dbl>, min <dbl>, tz <chr>, cfs <dbl>,
sampdt <dttm>
> 
> Regards,
> 
> Rich
> 
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