[R] For each entry type in column?

[Rui Barradas]

Hello,

If you want to loop through the columns of a data.frame you can do

for(i in names(df)){
     [code]
}

Another way would be

lapply(names(df), function(somecol) class(df[[somecol]]))

where class(df[[somecol]]) is just an example, you would use whatever 
fits your needs.

When you say that the column in question holds "levels" do you mean it's 
a factor? (factors are R's categorical variables.)

Hope this helps,

Rui Barradas


Em 06-11-2017 19:26, Matti Viljamaa escreveu:
> It’s sometimes faster to ask from someone who has already learnt the syntax.
> In this case one has to do e.g.
>
> names(data$somecol)
>
> To get the collection and then iteration through it is almost like in Python:
>
> for(i in names(data$somecol)) {
>     # do something
> }
>
>> Bert Gunter <bgunter.4567 at gmail.com> kirjoitti 6.11.2017 kello 19.55:
>>
>> Time to go through a tutorial or two! -- This forum cannot replace such self study.
>>
>> Your query evidences some basic confusion, but ?tapply or the equivalent lapply(split(...)) construct are most likely relevant.
>>
>> Cheers,
>> Bert
>>
>>
>>
>> Bert Gunter
>>
>> "The trouble with having an open mind is that people keep coming along and sticking things into it."
>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>
>> On Mon, Nov 6, 2017 at 9:40 AM, mviljamaa <mviljamaa at kapsi.fi <mailto:mviljamaa at kapsi.fi>> wrote:
>> How can I do a for loop that does to a data.frame column what:
>>
>> for x in xs:
>>
>> does in Python?
>>
>> Obviously the data.frame column in question holds "levels". What if the data.frame is in matrix form?
>>
>> BR, Matti
>>
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>
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