[R] Duplicated function with conditional statement

[Uwe Ligges]

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:

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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