[R] How to create a new variable based on parts of another character variable.

[Petr PIKAL]

Hi

If you want to get rid of regular expressions at all and your A values 
start AWI for Arctic and UFT for boreal you can

DF$D <- ifelse(substr(DF$A, 1,1) == "A", "Arctic", "Boreal")

Regards
Petr



> 
> Hello,
> I am just starting with R and I am having a (most probably) stupid 
problem
> by creating a new variable in a data.frame based on a part of another 
> character variable.
> 
> I have a data frame like this one:
> 
> 
> A         B       C
> AWI-test1   1      i
> AWI-test5   2      r
> AWI-tes75   56      z
> UFT-2      5      I
> UFT56      f      t
> UFT356      9j      t
> etc. etc.      89      t
> 
> 
> I now want to look in the variable A if the string AWI is present and 
then
> create a variable D and putting "Arctic" inside. However, if the string 
> UFT occurs in the variable A, then the variable D shall be "Boreal" etc. 
etc.
> 
> The resulting data.frame file should look like 
> A         B       C   D
> AWI-test1   1      i   Arctic 
> AWI-test5   2      r   Arctic
> AWI-tes75   56      z   Arctic
> UFT-2      5      I   Boreal
> UFT56      f      t   Boreal
> UFT356      9j      t   Boreal
> etc. etc.      89      t
> 
> 
> I know how to do this when I want to look for the entire string of A 
means
> when there is "AWI-test1" and then create the variable D with "Arctic" 
but
> not how to look only for a substring in A?
> Would be great if somebody might help.
> Thanks
> Philipp
> 
> 
> 
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