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Grep out columns using a list of strings

2 messages · Kate Ignatius, Boris Steipe

Original
Kate Ignatius
# 
Hi,

I have a list of 150 strings, say, ap,:

aajkss
dfghjk
sdfghk
...
xxcvvn


And I would l like to grep out these strings from column names in
another file, af,.   I've tried the following but none seem to work:

aps <- af[,grep(ap, colnames(af), value=TRUE)]
aps <- af[,grep(ap, colnames(af), value=FIXED)]
aps <- af[,grep(as.character(list(ap),colnames(af))]

and also aps <- unique (grep(ap, colnames(af))

Is there another way I can do this - maybe without using grep?

Thanks!

Kate.
Boris Steipe
# 
How about %in% ?


# preparing something that looks like I think your data looks like:
ap <- c("aajkss", "dfghjk", "sdfghk", "xxcvvn")
af <- matrix(1:10, nrow=2)
colnames(af) <- c("aajkss", "b", "c", "dfghjk", "e")

# doing what I think you need done:
ap[ap %in% colnames(af)]


Cheers,
B.

(PS. a reproducible example saves us all time and unnecessary effort. :-)
On May 8, 2015, at 3:50 PM, Kate Ignatius <kate.ignatius at gmail.com> wrote: