I'm looking to do something seemingly very simple. I would like to subset a data frame in R using the grepl() command -- or something like it -- on several different phrases without constructing a loop.
For example, I'd like to pull out all the rows for anyone named Bob or Mary:
## example data frame:
tmp = structure(list(Name = structure(c(6L, 8L, 9L, 7L, 2L, 3L, 10L,
1L, 5L, 4L), .Label = c("Alan", "Bob", "bob smith", "Frank",
"John", "Mary Anne", "mary jane", "Mary Smith", "Potter, Mary",
"smith, BOB"), class = "factor"), Age = c(31L, 23L, 23L, 55L,
32L, 36L, 45L, 12L, 43L, 46L), Height = 1:10), .Names = c("Name",
"Age", "Height"), class = "data.frame", row.names = c(NA, -10L
))
tmp
# Name Age Height
#1 Mary Anne 31 1
#2 Mary Smith 23 2
#3 Potter, Mary 23 3
#4 mary jane 55 4
#5 Bob 32 5
#6 bob smith 36 6
#7 smith, BOB 45 7
#8 Alan 12 8
#9 John 43 9
#10 Frank 46 10
## this doesn't work
mynames=c('bob','mary')
tmp[grepl(mynames,tmp$Name,ignore.case=T),]
Any ideas would be helpful!
You can combine your mynames
vector with the regular expression operator |
and use grep
.
tmp[grep(paste(mynames, collapse='|'), tmp$Name, ignore.case=TRUE),]
# Name Age Height
# 1 Mary Anne 31 1
# 2 Mary Smith 23 2
# 3 Potter, Mary 23 3
# 4 mary jane 55 4
# 5 Bob 32 5
# 6 bob smith 36 6
# 7 smith, BOB 45 7