[R] using complete.cases() with nested factors

[Gabor Grothendieck]

See ?subset and ?ave and try this:

subset(DF, ave(year, year, FUN = length) == 12)


On Thu, Sep 4, 2008 at 5:04 PM, Andrew Barr <wabarr at gmail.com> wrote:
> Hello,
>
> This maybe a newbie question.  I have a dataframe that looks like the sample
> at the bottom of the email.  I have monthly precipitation data from several
> sites over several years.  For each site, I need to extract years that have
> a complete series of 12 monthly precipitation values, while excluding that
> year for sites with incomplete data.  I can't figure out how to do this
> gracefully (i.e. without a silly for loop).  Any help will be appreciate,
> thanks!
>
> Andrew
>
> SiteID    year    month    precip(mm)
> 670090    1941    jan    2998
> 670090    1941    feb    1299
> 670090    1941    mar    1007
> 670090    1941    apr    354
> 670090    1941    may    88
> 670090    1941    jun    156
> 670090    1941    jul    8
> 670090    1941    aug    4
> 670090    1941    sep    8
> 670090    1941    oct    58
> 670090    1941    nov    397
> 670090    1941    dec    248
> 670090    1942    jan    NA
> 670090    1942    feb    380
> 670090    1942    mar    797
> 670090    1942    apr    142
> 670090    1942    may    43
> 670090    1942    jun    14
> 670090    1942    jul    70
> 670090    1942    aug    51
> 670090    1942    sep    0
> 670090    1942    oct    10
> 670090    1942    nov    235
> 670090    1942    dec    405
>
> --
> Andrew
>
>        [[alternative HTML version deleted]]
>
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