分析推文时出现streamR字符问题

Question

file = "tweets.json"
track = "kikik,kükükü,üğüğü"
lang = "tr"
minutes = 0.5
time = 60*minutes
filterStream(file.name = file, 
             track = track,
             language = lang,
             timeout = time, 
             oauth = my_oauth)

当我使用此代码并开始从我的帐户捕获推文时，找不到该推文。仅当我使用İ，Ö，Ü，Ğ字符时才会发生此错误。 ı更改了编码设置，但不起作用。我能做什么？