error in swirlExpectation(condition(object)) :
could not find function "is_equivalent_to"
I didn't realize that you were using R Programming Alt.
Unfortunately R Programming Alt is no longer supported.
Please use R Programming instead.
说是R Programming Alt
已经不再支持了,
所以我们在导入swirl
的课程时不要选 R Programming Alt
,
换成R Programming
就ok了.