[R] substitute

[Prof Brian Ripley]

On Fri, 16 May 2003, Wladimir Eremeev wrote:

>   I have troubles with 'substitute'.
>   I have the data frame with vectors data$area.0, data$area.20, etc...
>   Command
>   
>   substitute(data$area.lon,list(lon=20))
> 
>   returns
> 
>   data$area.lon
> 
>   but is expected to return data$area.20
> 
>   Where did I do mistakes?

The symbol is area.lon, not lon.  substitute only work on whole symbols, 
and `.' is just part of the alphabet allowed in syntactic names.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595