[R] conditional filling of data.frame - improve code

[Jeff Newmiller]

What a strange objection. You wouldn't keep the inline definition of expts in working code... that would be in a reference data file, and the merge is one line.

On March 10, 2022 11:24:27 PM PST, Ivan Calandra <ivan.calandra using rgzm.de> wrote:
>Thank you Jeff and Tim for your ideas. Indeed merge/join is probably the 
>nicest way. Still, the code becomes much longer because I need more 
>formatting of the input and output objects than with my ugly for loop :)
>
>Cheers,
>Ivan
>
>--
>Dr. Ivan Calandra
>Imaging lab
>RGZM - MONREPOS Archaeological Research Centre
>Schloss Monrepos
>56567 Neuwied, Germany
>+49 (0) 2631 9772-243
>https://www.researchgate.net/profile/Ivan_Calandra
>
>Le 10/03/2022 à 18:58, Ebert,Timothy Aaron a écrit :
>> You could try some of the "join" commands from dplyr.
>> https://dplyr.tidyverse.org/reference/mutate-joins.html
>> https://statisticsglobe.com/r-dplyr-join-inner-left-right-full-semi-anti
>>
>>
>> Regards,
>> Tim
>> -----Original Message-----
>> From: R-help <r-help-bounces using r-project.org> On Behalf Of Jeff Newmiller
>> Sent: Thursday, March 10, 2022 11:25 AM
>> To: r-help using r-project.org; Ivan Calandra <ivan.calandra using rgzm.de>; R-help <r-help using r-project.org>
>> Subject: Re: [R] conditional filling of data.frame - improve code
>>
>> [External Email]
>>
>> Use merge.
>>
>> expts <- read.csv( text =
>> "expt,sample
>> ex1,sample1-1
>> ex1,sample1-2
>> ex2,sample2-1
>> ex2,sample2-2
>> ex2,sample2-3
>> ", header=TRUE, as.is=TRUE )
>>
>> mydata <- data.frame(sample = c("sample2-2", "sample2-3", "sample1-1", "sample1-1", "sample1-1", "sample2-1"))
>>
>> merge( mydata, expts, by="sample", all.x=TRUE )
>>
>>
>> On March 10, 2022 7:50:23 AM PST, Ivan Calandra <ivan.calandra using rgzm.de> wrote:
>>> Dear useRs,
>>>
>>> I would like to improve my ugly (though working) code, but I think I
>>> need a completely different approach and I just can't think out of my box!
>>>
>>> I have some external information about which sample(s) belong to which
>>> experiment. I need to get that manually into R (either typing directly
>>> in a script or read a CSV file, but that makes no difference):
>>> exp <- list(ex1 = c("sample1-1", "sample1-2"), ex2 = c("sample2-1",
>>> "sample2-2" , "sample2-3"))
>>>
>>> Then I have my data, only with the sample IDs:
>>> mydata <- data.frame(sample = c("sample2-2", "sample2-3", "sample1-1",
>>> "sample1-1", "sample1-1", "sample2-1"))
>>>
>>> Now I want to add a column to mydata with the experiment ID. The best I
>>> could find is that:
>>> for (i in names(exp)) mydata[mydata[["sample"]] %in% exp[[i]],
>>> "experiment"] <- i
>>>
>>> In this example, the experiment ID could be extracted from the sample
>>> IDs, but this is not the case with my real data so it really is a
>>> matter of matching. Of course I also have other columns with my real data.
>>>
>>> I'm pretty sure the last line (with the loop) can be improved in terms
>>> of readability (speed is not an issue here). I have close to no
>>> constraints on 'exp' (here I chose a list, but anything could do), the
>>> only thing that cannot change is the format of 'mydata'.
>>>
>>> Thank you in advance!
>>> Ivan
>>>
>> --
>> Sent from my phone. Please excuse my brevity.
>>
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>
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-- 
Sent from my phone. Please excuse my brevity.