计算列中句号或星号的数目。

Question

基本上，我有一个名为XX$pitch_by_pitch的列，它的值为(F、S、B、X、.、*)等，我正在计算列中有多少字符不是句号或星号。

示例：

pitch=data.frame(c(".CX",".BSCBS",".BSBX",".D",".FFB*B."))
names(pitch)[1]="pitch_by_pitch"
pitch$row=row.names(pitch)
pitch$pitch_by_pitch=as.character(pitch$pitch_by_pitch)
pitch$num=nchar(pitch$pitch_by_pitch)

显然，最后一行计数所有字符，但我想删除句号和星号。

我尝试过这样的方法：

count.slashes <- function(string)sum(unlist(strsplit(string, NULL)) == "*") 
within(x, Col2 <- vapply(Col1, count.slashes, 1)) 
pbp$pitchstar=which(unlist(strsplit(pbp$pitch_by_pitch,NULL)) == '*') 
pbp$pitchstar=str_count(pbp$pitch_by_pitch, "*")
pbp$star=length(which(pbp$pitch_by_pitch == '*'))

Answer 1

试试pitch$num=nchar(gsub("\\*|\\.", "", pitch$pitch_by_pitch))。

gsub("\\*|\\.", "", pitch$pitch_by_pitch)删除pitch_by_pitch列中的所有*或.。之后，使用nchar计数字符就足够了：

gsub("\\*|\\.", "", pitch$pitch_by_pitch)
# [1] "CX"    "BSCBS" "BSBX"  "D"     "FFBB"