[R] intersection in data frame

[Dénes Tóth]

Or if your data is really large, you can try data.table::dcast().

 > library(data.table)
 > dcast(ID ~ station, data = as.data.table(df1))
    ID xy xz
1: 12 15 20
2: 13 16 19

(Note: instead of `as.data.table()`, you can use `setDT` or create your 
object as a data.table in the first place.)


On 10/13/22 11:22 PM, Rui Barradas wrote:
> Hello,
> 
> To reshape from long to wide format, here are two options:
> 
> 
> df1 <- 'ID    station  value
> 12      xy        15
> 12      xz        20
> 13       xy       16
> 13       xz       19'
> df1 <- read.table(textConnection(df1), header = TRUE)
> 
> 
> # base R
> reshape(df1, direction = "wide", idvar = "ID", timevar = "station")
> #>   ID value.xy value.xz
> #> 1 12       15       20
> #> 3 13       16       19
> 
> # tidyverse
> tidyr::pivot_wider(df1, ID, names_from = station)
> #> # A tibble: 2 × 3
> #>      ID    xy    xz
> #>   <int> <int> <int>
> #> 1    12    15    20
> #> 2    13    16    19
> 
> 
> This question is StackOverflow question [1].
> 
> [1] 
> https://stackoverflow.com/questions/5890584/how-to-reshape-data-from-long-to-wide-format 
> 
> 
> 
> Hope this helps,
> 
> Rui Barradas
> 
> 
> Às 19:08 de 13/10/2022, Gábor Malomsoki escreveu:
>> Dears,
>>
>> i need to create from a column of observations variables in a datafram 
>> like
>> this way:
>> example:
>> original:
>> ID    station  value
>> 12      xy        15
>> 12      xz        20
>> 13       xy       16
>> 13       xz       19
>>
>> new df:
>>
>>   ID      xy     xz
>> 12      15     20
>> 13      16     19
>>
>> i have been looking around for examples, but i could not find any how to
>> change my df.
>> I would like to make regression analysis on the values from different
>> production stations, so my df is very huge.
>>
>> Please help on finding the package, description or anything else could 
>> help.
>>
>> Thank you in advance!
>>
>> Best regards
>> Malo
>>
>>     [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>