On 14/02/2012 9:54 AM, Johannes Radinger wrote:
Hi,
I'd like to know if it is possible to use wildcards * for indexing...
E.g. I have a vector of strings. Now I'd like to select all elements
which start with A_*? I'd also need to combine that with logical operators:
"Select all elements of a vector that start with A (A*) OR that start with B
(B*)"
Probably that is quite easy. I looked into grep() which I think might perform
such tasks, but probably there is a more straigth forward solution.
a<- c("A_A","A_B","C_A","BB","A_Asd")
a[a=="A_A"| a=="A_B"] # here I'd like an index but with wildcard
Try grepl():
a[grepl("^[AB]", a)]
is probably the simplest way for your example.
Duncan Murdoch
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