R计数次数字出现在列表的元素中

时间:2012-07-09 21:09:13

标签: r list apply stringr

我有一个由单词组成的列表。

> head(splitWords2)
[[1]]
 [1] "Some"        "additional"  "information" "that"        "we"          "would"       "need"        "to"          "replicate"   "the"        
[11] "experiment"  "is"          "how"         "much"        "vinegar"     "should"      "be"          "placed"      "in"          "each"       
[21] "identical"   "container"   "or"          "what"        "tool"        "use"         "measure"     "mass"        "of"          "four"       
[31] "different"   "samples"     "and"         "distilled"   "water"       "rinse"       "after"       "taking"      "them"        "out"        

[[2]]
 [1] "After"       "reading"     "the"         "expirement"  "I"           "realized"    "that"        "additional"  "information" "you"        
[11] "need"        "to"          "replicate"   "expireiment" "is"          "one"         "amant"       "of"          "vinegar"     "poured"     
[21] "in"          "each"        "container"   "two"         "label"       "containers"  "before"      "start"       "yar"         "and"        
[31] "three"       "write"       "a"           "conclusion"  "make"        "sure"        "results"     "are"         "accurate" 

我有一个单词向量,我想计算列表中每个元素的出现次数,而不是整个列表中出现的总次数。

我认为这样做的方法是str_count()包中的stringr函数和*ply()函数之一的组合,但我无法使其正常工作。< / p>

numWorder1 <- sapply(ifelse(str_count(unlist(splitWords2), ignore.case("we" ) )> 0, 1, 0))

其中“我们”最终将是一个单词矢量中的单词来计算出现的。

我的理想输出是:

lineNum       count
   1           0
   2           1
   3           1
   4           0
  ...         ...

有什么建议吗?

4 个答案:

答案 0 :(得分:6)

对于一个特定的词:

words <- list(a = c("a","b","c","a","a","b"), b = c("w","w","q","a"))
$a
[1] "a" "b" "c" "a" "a" "b"

$b
[1] "w" "w" "q" "a"
wt <- data.frame(lineNum = 1:length(words))
wt$count <- sapply(words, function(x) sum(str_count(x, "a")))
  lineNum count
1       1     3
2       2     1

如果向量w包含您要计算的单词:

w <- c("a","q","e")
allwords <- lapply(w, function(z) data.frame(lineNum = 1:length(words), 
            count = sapply(words, function(x) sum(str_count(x, z)))))
names(allwords) <- w
$a
  lineNum count
a       1     3
b       2     1

$q
  lineNum count
a       1     0
b       2     1

$e
  lineNum count
a       1     0
b       2     0

答案 1 :(得分:3)

这样的事情:

wordlist <- list(
    c("the","and","it"),
    c("we","and","it")
)
require(plyr); require(stringr)
> ldply(wordlist, function(x) str_count(x, "we"))
  V1 V2 V3
1  0  0  0
2  1  0  0

答案 2 :(得分:2)

library(qdap)

#create a fake data set like yours:
words <- list(first = c("a","b","c","a","a","bc", "dBs"), 
    second = c("w","w","q","a"))
## termco functions require sentence like structure in a data frame so covert:
words2 <- list2df(lapply(words, paste, collapse = " "), "wl", "list")[2:1]


## trailing and leading spaces are important in match terms
## both a trailing and leading space will match exactly that trerm
termco(text.var=words2$wl, grouping.var=words2$list, match.list=c(" a "))
termco(words2$wl, words2$list, match.list=c(" b ", " a "))

## notice no space at the end of b finds and case of b + any.chunk
termco(words2$wl, words2$list, match.list=c(" b", " a "))

## no trailing/leading spaces means find any words containing the chunk b
termco(words2$wl, words2$list, match.list=c("b", " a "))

#ignores case
termco(words2$wl, words2$list, match.list=c("b", " a "), ignore.case=T)

## Last use yields:
## 
##     list word.count  term(b) term( a )
## 1  first          7 3(42.86)  2(28.57)
## 2 second          4        0     1(25)
## Also:


## transpose like function that transposes a raw matrix 
with(words2, termco2mat(termco(wl, list, match.list=c("b", " a "))))

## Which yields raw.score(percentage):
## 
##   first second
## b     2      0
## a     2      1

请注意,termco创建的类实际上是data.frames列表。

raw =原始频率计数(数字) prop =计数比例(数字) rnp =原始和比例合并(字符)

使用Scott的例子:

words <- list(
    first=c("the","and","it", "we're"),
    second=c("we","and","it")
)
words2 <- data.frame(list=names(words), 
    wl=unlist(lapply(words, paste, collapse=" ")))

termco(words2$wl, words2$list, match.list=c(" we ", " we"))
termco(words2$wl, words2$list, match.list=c(" we ", " we"), short.term = FALSE)

答案 3 :(得分:0)

为简单起见,您可以始终坚持使用基础包中的grep ...

LinesList <- list ( "1"=letters[1:10], "2"=rep(letters[1:3],3) )
CountsA <- grep("[a]", LinesList) # find 'a' in each element of list
length(CountsA) <- length(LinesList) # gives NAs if not counted
data.frame( lineNum = names(LinesList), count = CountsA)