例子 # declaring an empty data framedata_frame1<-data.frame(col1=NA,col2=NA,col3=NA,col4=NA)[numeric(0),]# printing data frameprint("Data Frame :")print(data_frame1) Bash Copy 输出 [1]“DataFrame:“[1]col1 col2 col3 col4<0rows>(or0-length row.names) Bash Copy 方法2:以NU...