startsWith
nchar
nzchar
paste
paste0
grepl
grep
gsub
sub
trimws
toupper
tolower
endsWith
strsplit
substr
chartr
formatC
which
which_min
which_max
diff
cumsum
cumprod
cummax
cummin
rev
duplicated
setdiff
intersect
union
unique
seq_along
seq_len
seq
r_range
sign
trunc
ceiling
floor
sqrt
log
log2
log10
exp
abs
var
sd
mean
median
quantile
scale
round
list_files
file_exists
dir_exists
basename
dirname
file_path
table
prop_table
margin_table
lapply
sapply
vapply
tapply
rapply
Filter
Map
Reduce
head
tail
length
nrow
ncol
dim
summary
rstr
vec
startsWith(x, prefix)
Return True if x starts with prefix. Vectorised.