[R] Using multiple dat files

[Bert Gunter]

Sorry, wrong language.
"through the function's closures" in my email should be:
through the function's chain of environments. (A function in R *is* a
closure).

-- Bert



On Wed, Nov 6, 2024 at 12:46 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:

> "It seems therefore that there is no other way than read in individually
> > 100 weather tables using read.tables., right? Using file.choose() doesn't
> change the work."
>
> Yes. With that many files, file.choose() does not make sense. However, I
> still do not understand what is the problem with using lapply() on the
> character vector of file names with read.table() as you did in your
> original post to read in all the files as components of the W list. As data
> frames are also lists, you can extract individual columns as you did before
> using  the $ extractor, i.e. W[[1]]$year, etc.. You can also use data frame
> indices for the columns, i.e. W[[1]][ ,1] or W[[1]][ ,"year"] . All of
> which I believe you know.
>
> However, I will hazard a *guess* (so exercise due diligence and check) as
> to the cause of your original error,
>
> "dd(data = W[[1]]$Precip, time.scale = W[[1]]$year)
> Fehler in W[[1]]$year : $ operator is invalid for atomic vectors'
>
> even though I know **nothing** about the dd() function. My guess is:
> "data" is usually an argument to a function that tells it to use
> "nonstandard evaluation" to look for arguments and other names in the
> function first in the "data" argument, rather than by following R's
> "standard" evaluation by looking first through the function's closures.
> **If** this guess is correct, the call you gave above should be something
> like:
>
> dd(data = W[[1]], time.scale = year, precip = Precip,...)
>
> where precip (small "p") is a formal argument of the dd() function and
> Precip is a column in the data frame W[[1]].  If this is wrong, my
> apologies, and feel free to ignore without responding.
>
> Best,
> Bert
>
> On Wed, Nov 6, 2024 at 10:59 AM Sibylle Stöckli <sibylle.stoeckli using gmx.ch>
> wrote:
>
>> Dear Rui
>> Dear Bert
>>
>> Many thanks
>>
>> Solution
>> filelist <- list.files(path =
>> "O:/Data-Work/2.../Daten_RA-MeteoCH_1990-2021", pattern='*.dat', all.files=
>> T, full.names= T)
>> AAR<-read.table(filelist[1])
>>
>> It seems therefore that there is no other way than read in individually >
>> 100 weather tables using read.tables., right? Using file.choose() doesn't
>> change the work.
>>
>> Yes my .dat files are data.frames
>>
>> > str(W[[1]])'data.frame':	11688 obs. of  7 variables:
>>  $ year  : num  1990 1990 1990 1990 1990 1990 1990 1990 1990 1990 ...
>>  $ DOY   : num  1 2 3 4 5 6 7 8 9 10 ...
>>  $ Ta    : num  -2.67 -2.77 -2.23 -2.21 -0.98 0.82 0.49 -1.02 -2.31 -3.36 ...
>>  $ Tmin  : num  -3.5 -3.7 -4.26 -2.87 -2.98 0.3 -0.83 -1.27 -3 -3.82 ...
>>  $ Tmax  : num  -1.13 -0.15 -0.13 -0.45 1 1.87 1.72 -0.35 -0.85 -2.3 ...
>>  $ Precip: num  0 0 0 0 0.45 1.81 0.03 0 0 0 ...
>>  $ rSSD  : num  0 0.08 0 0 0.08 0 0 0 0 0 ...
>>
>>
>> *Gesendet: *Mittwoch, 6. November 2024 um 18:28
>> *Von: *"Bert Gunter" <bgunter.4567 using gmail.com>
>> *An: *"Sibylle Stöckli" <sibylle.stoeckli using gmx.ch>
>> *CC: *r-help using r-project.org
>> *Betreff: *Re: [R] Using multiple dat files
>> Not quite sure if I understand you.
>>
>> list.files() simply returns a character vector(not a list). You can
>> simply use a vector index to select whatever file you wish to read. So if
>> your desired filename is the 5th element of filelist above, something like
>>
>> myfile <- read.table(filename[5], ...)
>>
>> You can also use regular expressions to choose a bunch of files that have
>> some common signature to their names that you can read in simultaneously
>> using your "filelist" vector of names via something like:
>>
>> myfiles <- lapply(grep("weath", filelist, value = TRUE), \(x)
>> read.table(x,...))
>> ### Note that the result of lapply *is* a list, so use list indexing for
>> extraction from myfiles.
>>
>>
>> You can also choose files to read interactively (via a GUI interface)
>> using file.choose() instead of using list.files() if you prefer to do it
>> that way.
>>
>> Cheers,
>> Bert
>>
>> On Wed, Nov 6, 2024 at 8:25 AM Sibylle Stöckli via R-help <
>> r-help using r-project.org> wrote:
>>
>>> Dear community
>>>
>>> To import multiple .dat  weather files I am using list.files().
>>> I intend to use the R package “ClimInd” to calculate different
>>> agroclimatic indicators.
>>>
>>> Question: Is there another solution to import multiple .dat files so
>>> that I can select elements from the list, e.g. one specific weather file
>>> (example AAR_DailyWeather)?
>>>
>>>
>>> # Import multiple .dat files weather data
>>> filelist <- list.files(path =
>>> "O:/Data-Work/……./Daten_RA-MeteoCH_1990-2021", pattern='*.dat', all.files=
>>> T, full.names= T)
>>> W <- lapply(filelist, function(x) read.table(x, header = TRUE, sep = "",
>>> colClasses = "numeric", comment.char = ""))
>>> W[[1]]
>>>
>>> > dd(data = W[[1]]$Precip, time.scale = W[[1]]$year)
>>> Fehler in W[[1]]$year : $ operator is invalid for atomic vectors
>>>
>>> Kind regards
>>> Sibylle
>>>
>>>
>>>
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>>
>>

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