r - 从短语列表中生成二元组，class = "omit", R

Question

我怎样才能用这个数据结构制作二元组？根据我的尝试，我不断收到这些错误，之后我想制作一个词云。

Error in UseMethod("pull") : 
  no applicable method for 'pull' applied to an object of class "character" 

或者

Error in UseMethod("tm_map", x) : 
  no applicable method for 'tm_map' applied to an object of class "character"

structure(c("phd fellow", "java developer intern", "optical engineer", 
"senior dwh bi engineer", "senior software engineer", "software developer", 
"data engineer", "application software engineer", "software developer", 
"senior web developer", "web developer", "software engineer", 
"software engineer", "trainee es computer", "associate software engineer", 
"fullstack ios developer", "technical delivery manager project manager", 
"software architect", "software developer", "student assistant", 
"web communication consultance", "heb retail application", "", 
"web developer", "frontend engineer and teamlead frontend", "web designer developer", 
"computational scientist backend developer", "junior data analyst", 
"fullstack engineer", "java software developer", "java junior programmer", 
"software engineer", "android developer", "android software engineer", 
"software developer", "fullstack developer", "embedded software intern", 
"android developer", "software developer intern", "supervisor support", 
"software engineer", "senior android developer", "fullstack android developer", 
"software engineer", "senior designer", "ceo pr marketing", "regional head of experience", 
"art director", "software entwickler", "junior it security analyst", 
"developement lead", "head of engineering", "it organisation", 
"development sales", "qa tester", "senior software developer", 
"it custom computer service"), na.action = structure(c(12L, 59L
), class = "omit"))

标签： r