删除R中的观察结果

Question

我有一个包含变量violation1的数据框，其中包含违规类型。

对于某些字符串，我使用下面的代码将它们排除在外。

camparking <- camparking[ grep("OTHER", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("BL- BIKE LANE", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("CENTER STRIP/ISLAND", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("NOT IN METER SPACE", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("OVRNGHT HEAVY VEHCLE", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("PEDESTRIAN ZONE", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("SNOW/WEATHER EMRGY", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("DRIVEWAY", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("HANDICAP RAMP", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("OVER 1FT FROM CURB", camparking$Violation1, invert = TRUE) , ]
camparking <- camparking[ grep("TAXI STAND", camparking$Violation1, invert = TRUE) , ]

我使用summary（）来总结每种违规类型的总数，排除的字符串显示为零值。

当我使用此结果绘制条形图时，条形图将显示包含零的值。

1）有没有办法删除这些字符串，使其不会显示在条形图中？恩。删除BL-BIKE LANE或TAXI STAND？

2）有没有办法在该图表的空白处创建一个框，我可以列出违规类型？