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

[Ivan Calandra]

In my first trials, I made a typo, which resulted in more columns than 
needed in the output of merge, which is why I needed more formatting. 
But now, it is indeed done all in one line and it is, as I said already, 
nicer anyway!

--
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 11/03/2022 à 08:47, Jeff Newmiller a écrit :
> 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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