[R] Strange and disturbing bug

Duncan Temple Lang duncan at research.bell-labs.com
Tue Mar 18 15:28:37 CET 2003

Hi Steve.

This is very much a feature, not a bug, and unless I am mistaken does
not relate to the use of a "two part name" (i.e. x.pair). 

The $ operator does partial matching on the names.  So fred$x yields
a partial match for fred$x.pair and gives you what you most likely
wanted.  Of course, using fred$x.pair makes this more readable in a
function/software, but partial matching is very convenient for
interactive use.


Steve Roberts wrote:
> How about this one? If I set a variable in a data.frame with a two-
> part name including a dot (say y.pair), and if the variable with the 
> name of the first part (y) doesn't but I ask for it's value I get the 
> value of the two-part name. Ie set fred$x.pair and print the value of 
> fred$x it gives me the value I set to fred$x.pair. Weird and 
> somewhat disturbing!
> Maybe an example makes it clearer:
>   Dr Steve Roberts 
>   steve.roberts at man.ac.uk
> Senior Lecturer in Medical Statistics,
> CMMCH NHS Trust and University of Manchester Biostatistics Group,
> 0161 275 5192 / 0161 276 5785
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help


Duncan Temple Lang                duncan at research.bell-labs.com
Bell Labs, Lucent Technologies    office: (908)582-3217
700 Mountain Avenue, Room 2C-259  fax:    (908)582-3340
Murray Hill, NJ  07974-2070       

More information about the R-help mailing list