[R] Issue with Transform function in R

ruipbarradas at sapo.pt ruipbarradas at sapo.pt
Thu Jul 21 14:33:09 CEST 2016


Hello,

Another thing to consider is to use Variable1 = NA, not '=='.
With '==' it will probably return TRUE/FALSE/NA.

Hope this helps,

Rui Barradas
 

Citando Ivan Calandra <ivan.calandra at univ-reims.fr>:

> This might not be the whole story, but part of the problem is that  
> you want to select a _*character string*_ greater/smaller than  
> another. That doesn't make much sense!
>
> I am not sure how to best compare two dates, but if you convert the  
> Date values into numeric, then that would work. The problem is that  
> it seems your Date values are character, and the comparison in your  
> ifelse is also a character.
>
> So something like this might work (untested because no reproducible example):
> transform(Df1, ifelse(as.numeric(Date) > numeric.value1 &&  
> as.numeric(Date) < numeric.value2, Variable1 ==NA, Variable1))
>
> HTH,
> Ivan
>
> --
> Ivan Calandra, PhD
> Scientific Mediator
> University of Reims Champagne-Ardenne
> GEGENAA - EA 3795
> CREA - 2 esplanade Roland Garros
> 51100 Reims, France
> +33(0)3 26 77 36 89
> ivan.calandra at univ-reims.fr
> --
> https://www.researchgate.net/profile/Ivan_Calandra
> https://publons.com/author/705639/
>
> Le 21/07/2016 à 03:00, Bhaskar Mitra a écrit :
>> Hello Everyone,
>>
>> I am trying to replace the values in the 2nd column (Variable 1)
>> corresponding to certain dates  (Date)
>>
>> with NAs as shown below. Both Date and Variable1 are numeric vectors . I am
>> trying to use the transform function
>>
>> as shown below but it doesn’t seem to work even though if I am not getting
>> any error
>>
>> Any suggestions/help in this regard?
>>
>> regards,
>>
>> ---------------------------------------------------------------------------------------------------------------------------------------------------------
>>
>> Df1 <- data.frame(Date, Variable1)
>>
>> a1 <- transform(Df1, ifelse(Date  > "010301000300 " && Date <
>> "010501000300", Variable1 ==NA, Variable1))
>>
>> Original Data frame
>>
>>      Date                          Variable1
>>
>> 010101000300                     1
>>
>> 010201000300                     2
>>
>> 010301000300                     3
>>
>> 010401000300                     4
>>
>> 010501000300                     5
>>
>> 010601000300                     6
>>
>> 010701000300                     7
>>
>> .
>>
>> .
>>
>> .
>>
>> ……….
>>
>> Transformed data frame (i hope to transform)
>>
>>       Date                       Variable1
>>
>> 010101000300                    1
>>
>> 010201000300                    2
>>
>> 010301000300                   NA
>>
>> 010401000300                   NA
>>
>> 010501000300                    NA
>>
>> 010601000300                    6
>>
>> 010701000300                    7
>>
>> ……….
>>
>>         [[alternative HTML version deleted]]
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at 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.htmland provide commented,  
> minimal, self-contained, reproducible code.

 

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