[R] Use of variables to reference to objects

[Patrick Burns]

The "get" function is the usual answer to this sort of question, but is 
not right
for this particular case.  Actually, a simpler answer works.

lines(spectral$Wavelength, spectral[[ paste("a", j, sep="") ]], col=j)

Using "get" would want to get objects with names like "spectral$a1"
rather than the "a1" component of "spectral".



Patrick Burns
patrick at burns-stat.com
+44 (0) 208 525 0696
http://www.burns-stat.com/    (new home of S Poetry)



Kris Nackaerts wrote:

> Hi,
>
> I'm new to R and looking for a way to use a variable to reference to 
> an object.
>
> I'm plotting several graphs on top of each other and want to do this 
> by a for loop. The field I want to graph have names like a1,a2,a3, ...
> I can't figure out how to get this working:
>
> It should look like this:
> lines(spectral$Wavelength,paste("spectral$a",j,sep=""),col=j)
>
> but the "paste()" does not seem to work in this context.
>
> Any help?
>
> Kind regards,
>
> Kris
>


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