[R] altering identity column

[David Winsemius]

On Apr 18, 2011, at 9:02 AM, Bodnar Laszlo EB_HU wrote:

> Hi there,
>
> I have a huge dataframe containing 70,000 observations.
>
> I have filtered this dataframe (let it's name be  
> "transformed_dataframe") as I wanted to select only those  
> observations which are greater than or equal to 60,001 regarding the  
> very first identity column.

I am guessing that what you want is something like

dfrm2 <- transformed_dataframe[rownames(transformed_dataframe) >=  
"60001" , ]

Or perhaps (if you carrying the thousands separator into the rownames:

dfrm2 <- transformed_dataframe[rownames(transformed_dataframe) >=  
"60,001" , ]

Or if you are using spaces then:

dfrm2 <- transformed_dataframe[rownames(transformed_dataframe) >= "60  
001" , ]

This would involve much less guessing if you offered the results of:

  str(transformed_dataframe)

>
> So I have a transformed dataframe now including 10,000 obeservations  
> (from 60,001 - to 70,000) and if you send  
> "head(transformed_dataframe)" into R it looks like this:
>
>                        variable1           variable2            
> variable3           variable4           ...
> 60  
> 001 
>               ...                    ...                     ...                    ...
> 60  
> 002 
>               ...                    ...                     ...                    ...
> 60  
> 003 
>               ...                    ...                     ...                    ...
> 60  
> 004 
>               ...                    ...                     ...                    ...
> 60  
> 005 
>               ...                    ...                     ...                    ...
>
> Sending "tail(transformed_dataframe)" into R it is going to be  
> something like:
>
>                        variable1           variable2            
> variable3           variable4           ...
> 69  
> 996 
>               ...                    ...                     ...                    ...
> 69  
> 997 
>               ...                    ...                     ...                    ...
> 69  
> 998 
>               ...                     ...                     ...                    ...
> 69  
> 999 
>               ...                    ...                     ...                    ...
> 70  
> 000 
>               ...                    ...                     ...                    ...
>
>
> Now is there a quick way to alter this indexing of rows in case of  
> my "transformed_dataframe"? I mean, I would like to get indices 1,  
> 2, 3, etc... instead of 60 001, 60 002, 60 003 etc...

rownames(transformed_dataframe) <- 1:10000


>
> So by sending "head(transformed_dataframe)" and  
> "tail(transformed_dataframe)" I would like to see:
>
>            variable1           variable2            
> variable3           variable4           ...
> 1 
>           ...                    ...                    ...                    ...
> 2 
>           ...                    ...                    ...                    ...
> 3 
>           ...                    ...                    ...                    ...
> 4 
>           ...                    ...                    ...                    ...
> 5 
>           ...                    ...                    ...                    ...
>
> and
>
>                        variable1           variable2            
> variable3           variable4           ...
> 9  
> 996 
>                 ...                    ...                    ...                    ...
> 9  
> 997 
>     ...                    ...                    ...                    ...
> 9  
> 998 
>                 ...                    ...                    ...                    ...
> 9  
> 999 
>                 ...                    ...                    ...                    ...
> 10  
> 000 
>               ...                    ...                    ...                    ...
>
> Thank you very much, best regards,
>
> Laszlo
> ______________________________________________________________________________________________


David Winsemius, MD
West Hartford, CT