[R] use list elements to subtract values from the dataframe

[Ashish Ranpura]

Dirkheld <dirk.bollen <at> soc.kuleuven.be> writes:
> I have a dataframe wf existing of a header with different labels and beneath
> the values of those labels :
> wf:
> label1  label2  ...
> 0,45    0,21
> 0,10    0,45 
> ....      ....
> 
> I have a list
> fl <- c("label2","label3",..)
> 
> Isn't possible to use the list elements in the list in order to subtract
> values from the dataframe? like :
> wf$fl[[1]] 
> When I do in R I get :NULL
> fl[[1]] gives  "label2"  so no problem here...
> 
> While wf$label1 works fine.
> 


Dirk, possibly not the most elegant solution, but I would use:

f1.indices = match(f1, names(wf))
wf[f1.indices[1]]

Good luck,

-Ash.

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Ashish Ranpura
Institute of Cognitive Neuroscience
University College London
17 Queen Square
London WC1N 3AR

tel: +44 (20) 7679 1126
web: http://www.icn.ucl.ac.uk