[R] Duplicated function with conditional statement

[David Winsemius]

On Jul 26, 2013, at 11:51 AM, Uwe Ligges wrote:

> 
> 
> On 25.07.2013 21:05, vanessa van der vaart wrote:
>> Hi everybody,,
>> I have a question about R function duplicated(). I have spent days try to
>> figure this out,but I cant find any solution yet. I hope somebody can help
>> me..
>> this is my data:
>> 
>> subj=c(1,1,1,2,2,3,3,3,4,4)
>> response=c('sample','sample','buy','sample','buy','sample','
>> sample','buy','sample','buy')
>> product=c(1,2,3,2,2,3,2,1,1,4)
>> tt=data.frame(subj, response, product)
>> 
>> the data look like this:
>> 
>>  subj response product
>> 1     1   sample       1
>> 2     1   sample       2
>> 3     1      buy          3
>> 4     2   sample       2
>> 5     2         buy       2
>> 6     3   sample       3
>> 7     3   sample       2
>> 8     3         buy       1
>> 9     4  sample       1
>> 10   4       buy        4
>> 
>> I want to create new  column based on the value on response and product
>> column. if the value on product is duplicated, then  the value on new column
>> is 1, otherwise is 0.
> 
> 
> According to your description:
> 

Agree that the description did not match the output. I tried to match the output using a rule that could be expressed as: 

 if( a "buy"- associated "product" value precedes the current "product" value){1}else{0}

-- 
David.

> tt$newcolumn <- as.integer(duplicated(tt$product) & tt$response=="buy")
> 
> which is different from what you show us below, where I cannot derive any systematic rule from.
> 
> Uwe Ligges
> 
>> but I want to add conditional statement that the value on product column
>> will only be considered as duplicated if the value on response column is
>> 'buy'.
>> for illustration, the table should look like this:
>> 
>> subj response product newcolumn
>> 1     1   sample       1          0
>> 2     1   sample       2          0
>> 3     1      buy          3          0
>> 4     2   sample       2          0
>> 5     2         buy       2          0
>> 6     3   sample       3          1
>> 7     3   sample       2           1
>> 8     3         buy       1           0
>> 9     4  sample       1            1
>> 10   4       buy       4             0
>> 
>> 
>> can somebody help me?
>> any help will be appreciated.
>> I am new in this mailing list, so forgive me in advance, If I did not  ask
>> the question appropriately.
>> 
>> 	[[alternative HTML version deleted]]
>> 
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>> and provide commented, minimal, self-contained, reproducible code.
>> 
> 
> ______________________________________________
> R-help at r-project.org mailing list
> 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.

David Winsemius
Alameda, CA, USA