我在用R读取.dbf文件的时候，出来现了下面的提示信息，打开读取进来的数据，发现比原dbf文件，多了X. X X1 X2 X3 X4 X5 X6这几列，并且值均为NA。我确定原dbf文件只有5列，导进来之后却成了13列.
到处查了都不知道怎么回事，哪位大神可以帮忙解答一下?
’ changed to: ‘X.’
Field name: ‘’ changed to: ‘X’
Field name: ‘’ changed to: ‘X.1’
Field name: ‘’ changed to: ‘X.2’
Field name: ‘’ changed to: ‘X.3’
Field name: ‘’ changed to: ‘X.4’
Field name: ‘’ changed to: ‘X.5’
Field name: ‘’ changed to: ‘X.6’