[R] stdev error

[Eric Berger]

try changing
Bse_ftv = mean(Bse_ftv)
to
Bse_ftv_mean = mean(Bse_ftv)

On Fri, Mar 11, 2022 at 4:15 PM Jeff Reichman <reichmanj using sbcglobal.net>
wrote:

> r-help forum
>
>
>
> When I run the following code
>
>
>
> my_tbl %>%
>
>   mutate(Bse_bwt = round(Bse_bwt * 2) / 2) %>%
>
>   group_by(Cat, Bse_bwt) %>%
>
>   summarize(count = n(), Bse_ftv = mean(Bse_ftv), stdev = sd(Bse_ftv))
>
>
>
> I get the following error:
>
>
>
> Error: `stdev` refers to a variable created earlier in this summarise().
>
> Do you need an extra mutate() step?
>
>
>
> I suspect it is because the standard deviation of a length-one vector is NA
> and R is errorerrors out on the standard deviation  of 1. So then I tried
>
>
>
> summarize(count = n(), Bse_ftv = mean(Bse_ftv), stdev = if(n()>1)
> sd(Bse_ftv) else 0) and this didn't seem to work either. So there has to be
> a way to add some sort of error checker to my standard deviation function
> to
> check if n > 1 and then take the standard deviation in dplyr.
>
>
>
> Jeff
>
>
>
>
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