我想计算两个日期之间的年差。这是一些测试数据；
O H L C StoHH StoLL K kM
2007-01-02 6220.8 6312.5 6220.8 6310.9 0.0 0.0 0.0000000 0.0000000
2007-01-03 6310.9 6322.0 6296.0 6319.0 0.0 0.0 0.0000000 0.0000000
2007-01-04 6319.0 6319.0 6261.0 6287.0 0.0 0.0 0.0000000 0.0000000
2007-01-05 6287.0 6287.0 6220.1 6220.1 0.0 0.0 0.0000000 0.0000000
2007-01-08 6220.1 6246.0 6187.0 6194.2 0.0 0.0 0.0000000 0.0000000
2007-01-09 6194.2 6218.5 6190.4 6196.1 0.0 0.0 0.0000000 0.0000000
2007-01-10 6196.1 6196.1 6142.0 6160.7 0.0 0.0 0.0000000 0.0000000
2007-01-11 6160.7 6233.1 6130.2 6230.1 0.0 0.0 0.0000000 0.0000000
2007-01-12 6230.1 6247.6 6204.3 6239.0 0.0 0.0 0.0000000 0.0000000
2007-01-15 6239.0 6279.7 6239.0 6263.5 0.0 0.0 0.0000000 0.0000000
2007-01-16 6263.5 6266.4 6206.4 6215.7 0.0 0.0 0.0000000 0.0000000
2007-01-17 6215.7 6227.0 6163.5 6204.5 0.0 0.0 0.0000000 0.0000000
2007-01-18 6204.5 6257.2 6204.5 6210.3 0.0 0.0 0.0000000 0.0000000
2007-01-19 6210.3 6243.3 6178.0 6237.2 6322.0 6130.2 0.5578734 0.1859578
2007-01-22 6237.2 6270.9 6215.8 6218.4 6322.0 6130.2 0.4598530 0.3392421
2007-01-23 6218.4 6240.7 6189.2 6227.6 6319.0 6130.2 0.5158898 0.5112054
2007-01-24 6227.6 6320.9 6227.6 6314.8 6320.9 6130.2 0.9680120 0.6479183
2007-01-25 6314.8 6335.1 6262.1 6269.3 6335.1 6130.2 0.6788662 0.7209227
2007-01-26 6269.3 6271.4 6226.4 6228.0 6335.1 6130.2 0.4773053 0.7080612
2007-01-29 6228.0 6253.7 6216.0 6239.9 6335.1 6130.2 0.5353819 0.5638511
Trs Trl TrsCum TrlCum CumBal CumRet
2007-01-02 0.0000 0.0000 0.0000 0.0000 1000000 1.00000
2007-01-03 810.0098 -810.0098 810.0098 -810.0098 1000000 1.00000
2007-01-04 -3200.0000 3200.0000 -2389.9902 2389.9902 1000000 1.00000
2007-01-05 -6689.9902 6689.9902 -9079.9804 9079.9804 1000000 1.00000
2007-01-08 -2589.9903 2589.9903 -11669.9707 11669.9707 1000000 1.00000
2007-01-09 189.9903 -189.9903 -11479.9804 11479.9804 1000000 1.00000
2007-01-10 -3539.9903 3539.9903 -15019.9707 15019.9707 1000000 1.00000
2007-01-11 6939.9903 -6939.9903 -8079.9804 8079.9804 1000000 1.00000
2007-01-12 889.9902 -889.9902 -7189.9902 7189.9902 1000000 1.00000
2007-01-15 2450.0000 -2450.0000 -4739.9902 4739.9902 1000000 1.00000
2007-01-16 -4779.9805 4779.9805 -9519.9707 9519.9707 1000000 1.00000
2007-01-17 -1120.0195 1120.0195 -10639.9902 10639.9902 1000000 1.00000
2007-01-18 579.9805 -579.9805 -10060.0097 10060.0097 1000000 1.00000
2007-01-19 2690.0390 -2690.0390 -7369.9707 7369.9707 1000000 1.00000
2007-01-22 -1880.0293 0.0000 -9250.0000 7369.9707 998120 0.99812
2007-01-23 920.0196 0.0000 -8329.9804 7369.9707 999040 0.99904
2007-01-24 8719.9707 0.0000 389.9903 7369.9707 1007760 1.00776
2007-01-25 -4550.0000 0.0000 -4160.0097 7369.9707 1003210 1.00321
2007-01-26 0.0000 4129.9805 -4160.0097 11499.9512 1007340 1.00734
2007-01-29 0.0000 -1189.9902 -4160.0097 10309.9610 1006150 1.00615
UlcRi UlcInd PFctL PFctW
2007-01-02 Inf 0 0.000 0.0000
2007-01-03 Inf 0 0.000 0.0000
2007-01-04 Inf 0 0.000 0.0000
2007-01-05 Inf 0 0.000 0.0000
2007-01-08 Inf 0 0.000 0.0000
2007-01-09 Inf 0 0.000 0.0000
2007-01-10 Inf 0 0.000 0.0000
2007-01-11 Inf 0 0.000 0.0000
2007-01-12 Inf 0 0.000 0.0000
2007-01-15 Inf 0 0.000 0.0000
2007-01-16 Inf 0 0.000 0.0000
2007-01-17 Inf 0 0.000 0.0000
2007-01-18 Inf 0 0.000 0.0000
2007-01-19 0.00000000 0 0.000 0.0000
2007-01-22 -0.18800293 0 -1880.029 0.0000
2007-01-23 -0.09600097 0 0.000 920.0196
2007-01-24 0.00000000 0 0.000 8719.9707
2007-01-25 -0.45149641 0 -4550.000 0.0000
2007-01-26 -0.04167853 0 0.000 4129.9805
2007-01-29 -0.15976123 0 -1189.990 0.0000
到目前为止，我所做的是;
sapply(a.1, class)
O H L C StoHH StoLL K kM
"numeric" "numeric" "numeric" "numeric" "numeric" "numeric" "numeric" "numeric"
Trs Trl TrsCum TrlCum CumBal CumRet UlcRi UlcInd
"numeric" "numeric" "numeric" "numeric" "numeric" "numeric" "numeric" "numeric"
PFctL PFctW
"numeric" "numeric"
time(a.1)
Error in hasTsp(x) : invalid time series parameters specified
as.yearmon(time(a.1))
Error in hasTsp(x) : invalid time series parameters specified
time(a.1[1,])
Error in hasTsp(x) : invalid time series parameters specified
as.numeric(a.1)
Error: (list) object cannot be coerced to type 'double'
a.1 <- data.frame(a.1)
我想做的是从ts的开始和结束日期算起以十进制表示的年数。我曾尝试将其转换为df并使用其他方法，但似乎无法弄清楚如何将ts列转换为可延展的形式以执行计算，有什么想法吗？