某一个list对象里面有一串数据。
比如
> l
[[1]]
[1] 116.19857 144.74631 124.18671  84.55319  44.38377  45.82889  52.56089
[8]  78.94560  79.01729 126.09473 126.25996 121.44622 138.08633  94.53887
[15] 148.08476  87.96127  54.74945  38.27613  42.32329  62.35817  66.33335
[22] 130.23335 137.95564 125.16395 124.05283 141.38226  90.12463  73.98447
[29]  54.54684  29.90310  50.44390  61.59896  98.54383 125.25719 160.34259
[36] 129.04938 110.66122 112.19142 102.70812  73.39132  58.00721  41.22968
[43]  38.16294  61.50956 104.30757 107.76878 160.15324 173.86076 167.85461
[50] 153.58899 108.65487  78.88346  51.97395  40.33940  45.73986  70.54365
[57]  80.10616 111.61009 156.07265 136.36282 120.36707 164.33562  95.23341
[64]  59.15205  54.78129  42.92529  44.39678  78.84485 109.96697  93.68070
[71] 158.97519 189.99384 151.87677 153.53394 120.66994  81.93810  44.05572
[78]  48.72369  51.18549  53.77425  78.62342 118.87374 149.46956 151.27539


我想用这些数据来画时间序列。
> lts<-ts(l,frequency=12,start=2002)
> plot(lts)
错误于xy.coords(x, NULL, log = log) :
  (串列)对象不能强制改变成'double'种类


这种情况下我改如何处理啊？