R中for循环的矢量化

你可以用outer.我假设你正在使用str_count从stringr包.

library(stringr)

texts <- c('abc', 'asdf', 'werd', 'ffssd')
patterns <- c('ab', 'd', 'w')

matches <- outer(texts, patterns, str_count)

# set dim names
colnames(matches) <- patterns
rownames(matches) <- texts
matches
      ab d w
abc    1 0 0
asdf   0 1 0
werd   0 1 1
ffssd  0 1 0

编辑

# or set names directly within 'outer' as noted by @RichardScriven
outer(setNames(nm = texts), setNames(nm = patterns), str_count)