Extracting subset of the data frame in R

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一向
一向 2021-01-12 23:43

Suppose I read a csv file into a data frame called \"d\". I wish to print the last 2 rows of this data frame. I tried the below but it is printing all the content starting f

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  •  佛祖请我去吃肉
    2021-01-13 00:36

    @mnel is correct that using tail() would probably be the easiest, however I think that your confusion has to do with how subset() and indexing work in general. In your example be mindful of how you index matrices and data.frames since

    d[(n:n - 1), ]
    

    is not the same as

    d[n:(n-1), ]
    

    so check the difference carefully since the order of operations are important to understand. The subset() function also indexes based on a logical indicator and has the form

     subset(object, subset = logicalvector)
    

    where the logical vector gives the rows that you want to extract. See ?subset for more detail.

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