[R] Issue with Transform function in R

[Ivan Calandra]

Oops, missed that one!

--
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 14:33, ruipbarradas at sapo.pt a écrit :
>
> 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 
> <mailto: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 <mailto: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 <mailto: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.
>
>