unexst_tokens无法使用tidytext包处理R中的向量

Question

我想使用tidytext包创建一个包含'ngrams'的列。使用以下代码：

library(tidytext)

unnest_tokens(tbl = president_tweets,
              output =  bigrams,
              input = text,
              token = "ngrams", 
              n = 2) 

但是当我运行这个时，我收到以下错误消息：

error: unnest_tokens expects all columns of input to be atomic vectors (not lists)

我的text专栏包含很多推文，其中的行看起来如下，并且是类字符。

president_tweets$text <– c("The United States Senate just passed the biggest in history Tax Cut and Reform Bill. Terrible Individual Mandate (ObamaCare)Repealed. Goes to the House tomorrow morning for final vote. If approved, there will be a News Conference at The White House at approximately 1:00 P.M.", 
    "Congratulations to Paul Ryan, Kevin McCarthy, Kevin Brady, Steve Scalise, Cathy McMorris Rodgers and all great House Republicans who voted in favor of cutting your taxes!", 
    "A  story in the @washingtonpost that I was close to rescinding the nomination of Justice Gorsuch prior to confirmation is FAKE NEWS. I never even wavered and am very proud of him and the job he is doing as a Justice of the U.S. Supreme Court. The unnamed sources dont exist!", 
    "Stocks and the economy have a long way to go after the Tax Cut Bill is totally understood and appreciated in scope and size. Immediate expensing will have a big impact. Biggest Tax Cuts and Reform EVER passed. Enjoy, and create many beautiful JOBS!", 
    "DOW RISES 5000 POINTS ON THE YEAR FOR THE FIRST TIME EVER - MAKE AMERICA GREAT AGAIN!", 
    "70 Record Closes for the Dow so far this year! We have NEVER had 70 Dow Records in a one year period. Wow!"
    )

---------更新：----------

看起来像sentimetr或exploratory包引起了冲突。没有这些我重新加载我的包，现在它再次工作！