我希望在图表的X轴上只保留"2006_4","2007_4","2008_4","2009_4","2010_4","2011_4","2012_4","2013_4"这几个刻度并把它们替换成"2006","2007","2008","2009","2010","2011","2012","2013"。但是当我添加了如下语句后运行出错:
<br />
pp1+stat_smooth(method="loess", aes(group=NA))+<br />
scale_x_discrete(breaks=C("2006_4","2007_4","2008_4","2009_4","2010_4","2011_4","2012_4","2013_4"))<br />
Error in C("2006_4", "2007_4", "2008_4", "2009_4", "2010_4", "2011_4", :
object not interpretable as a factor
即使在前面添加pdp$Period<-factor(pdp$Period)将Period列强制转换成向量格式仍然报告此错误,请问应该如何处理?
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