R help - Aug 2014 - how to extract word before /// in a data frame contain many thousands rows.

Dear All,

I appreciate if you can help me out this. I have a data frame contains many
thousand of rows, with some rows that has /// symbol,  as shown in in row 2, I
want to extract word before ///, such as in this case, CDH23. Many thanks.
Probe.Set.ID            Gene.Symbol
1  1552301_a_at                  CORO6
2  1552436_a_at CDH23 /// LOC100653137
3  1552477_a_at                   IRF6
4  1552685_a_at                  GRHL1
5    1552742_at                  KCNH8
6  1552752_a_at                  CADM2
7    1552799_at                TSNARE1
8  1552897_a_at                  KCNG3
9  1552902_a_at                  FOXP2
10   1552903_at               B4GALNT2


structure(list(Probe.Set.ID = c("1552301_a_at",
"1552436_a_at",
"1552477_a_at", "1552685_a_at", "1552742_at",
"1552752_a_at",
"1552799_at", "1552897_a_at", "1552902_a_at",
"1552903_at"),
    Gene.Symbol = c("CORO6", "CDH23 /// LOC100653137",
"IRF6",
    "GRHL1", "KCNH8", "CADM2",
"TSNARE1", "KCNG3", "FOXP2", "B4GALNT2"
    )), .Names = c("Probe.Set.ID", "Gene.Symbol"), row.names
= c(NA,
10L), class = "data.frame")


Stephen HK Wong

Try:
If dat is the dataset.


?? library(stringr)
??? res <- str_extract(dat$Gene.Symbol, perl('[[:alnum:]]+(?= \\/)'))
?res[!is.na(res)]
?#[1] "CDH23"

A.K.




On Thursday, July 31, 2014 9:54 PM, Stephen HK Wong <honkit at
stanford.edu> wrote:
Dear All,

I appreciate if you can help me out this. I have a data frame contains many
thousand of rows, with some rows that has /// symbol,? as shown in in row 2, I
want to extract word before ///, such as in this case, CDH23. Many thanks.
Probe.Set.ID? ? ? ? ? ? Gene.Symbol
1? 1552301_a_at? ? ? ? ? ? ? ? ? CORO6
2? 1552436_a_at CDH23 /// LOC100653137
3? 1552477_a_at? ? ? ? ? ? ? ? ?  IRF6
4? 1552685_a_at? ? ? ? ? ? ? ? ? GRHL1
5? ? 1552742_at? ? ? ? ? ? ? ? ? KCNH8
6? 1552752_a_at? ? ? ? ? ? ? ? ? CADM2
7? ? 1552799_at? ? ? ? ? ? ? ? TSNARE1
8? 1552897_a_at? ? ? ? ? ? ? ? ? KCNG3
9? 1552902_a_at? ? ? ? ? ? ? ? ? FOXP2
10?  1552903_at? ? ? ? ? ? ?  B4GALNT2


structure(list(Probe.Set.ID = c("1552301_a_at",
"1552436_a_at",
"1552477_a_at", "1552685_a_at", "1552742_at",
"1552752_a_at",
"1552799_at", "1552897_a_at", "1552902_a_at",
"1552903_at"),
? ? Gene.Symbol = c("CORO6", "CDH23 /// LOC100653137",
"IRF6",
? ? "GRHL1", "KCNH8", "CADM2",
"TSNARE1", "KCNG3", "FOXP2", "B4GALNT2"
? ? )), .Names = c("Probe.Set.ID", "Gene.Symbol"), row.names
= c(NA,
10L), class = "data.frame")


Stephen HK Wong

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