我在r中有数据框，文本列必须大致分类到不同的列
Type Broader_Type
stiff clay stiff clay
coarse sand coarse sand
-
-
-
coasrse sand coarse sand
coasrse sand coarse sand
COARSE coarse sand
stiff clay stiff clay
marine clay marine clay
medium sand silt medium sand
rock rock
hard strata hard strata
type d above coarse type D
medium sand with medium sand
但是在观察中存在拼写错误或一些拼写错误。我们怎样才能在R中做到并使其概括？