我有word1和word2的值，但未能在R plz中找到共现分析代码和逐点互信息代码对我有帮助
word 1 word 2 count word 1 count word 2 count of co-occurrences PMI
puerto rico 1938 1311 1159 10.0349081703
hong kong 2438 2694 2205 9.72831972408
los angeles 3501 2808 2791 9.56067615065
carbon dioxide 4265 1353 1032 9.09852946116