求教您我该用什么命令完成包括三个变量的折线图,以表示为日期var1为横轴,主要是第一个变量var1我不知道该怎么处理,怎样才能把他变为日期呢?谢谢您
数据格式如下:
var1 var2 var3
200801 109.64 26.6
200802 87.3678 6.5
200803 108.9629 30.6
200804 118.7711 21.9
200805 120.4965 28.1
200806 121.1796 17.2
200807 136.675 26.9
200808 134.8727 21.1
200809 136.4321 21.5
200810 128.327 19.2
200811 114.9873 -2.2
200812 111.1572 -2.8
200901 90.4536 -17.5
200902 64.89465 -25.7
200903 90.29055 -17.1
200904 91.93472 -22.6
200905 88.75789 -26.4
200906 95.51202 -21.4
200907 105.4202 -23
200908 103.707 -23.4
200909 115.938 -15.2
200910 110.7624 -13.8
200911 113.6534 -1.2
200912 130.7239 17.7
201001 109.4753 21
201002 94.52271 45.7
201003 112.1118 24.3
201004 119.9207 30.5
201005 131.7607 48.5