Extracting some rows from a data frame - lapses into a vector

2 messages · Ajay Shah, Dieter Menne

Mon, Aug 15, 2005 11:18 PM #

I have a data frame with one column "x":

`data.frame':   20 obs. of  1 variable:
 $ x: num  0.0495 0.0986 0.9662 0.7501 0.8621 ...

Normally, I know that the notation dataframe[indexes,] gives you a new
data frame which is the specified set of rows. But I find:

num [1:10] 0.0495 0.0986 0.9662 0.7501 0.8621 ...

Here, it looks like the operation
      data[1:10,]
has converted it from type data frame into a numeric vector. Why does
this happen, and what can I do about it?

Ajay Shah                                                   Consultant
ajayshah at mayin.org                      Department of Economic Affairs
http://www.mayin.org/ajayshah           Ministry of Finance, New Delhi

Dieter Menne

Mon, Aug 15, 2005 11:26 PM #

Ajay Narottam Shah <ajayshah <at> mayin.org> writes:

....

Check parameter "drop" in the documentation of "[" or Extract. The 
simplification to a vector is default behavior for historical reasons, but 
somewhat confusing.

Dieter