我试图逐行存储ts对象.用于创建时间序列的月度数据(1980年和1981年的24个月值)在DT中按行顺序存储,因此我只想在DT中添加一列来存储每行的"ts"对象() .这是一个可重复的例子,我尝试了三种不同的选项,但它们似乎都没有像我预期的那样工作.
library(data.table)
DT <- data.table(ID=seq(1:10),
JAN_1980=rnorm(1:10),FEB_1980=rnorm(1:10),MAR_1980=rnorm(1:10),APR_1980=rnorm(1:10),MAY_1980=rnorm(1:10),JUN_1980=rnorm(1:10),JUL_1980=rnorm(1:10),AUG_1980=rnorm(1:10),SEP_1980=rnorm(1:10),OCT_1980=rnorm(1:10),NOV_1980=rnorm(1:10),DEC_1980=rnorm(1:10),JAN_1981=rnorm(1:10),FEB_1981=rnorm(1:10),MAR_1981=rnorm(1:10),APR_1981=rnorm(1:10),MAY_1981=rnorm(1:10),JUN_1981=rnorm(1:10),JUL_1981=rnorm(1:10),AUG_1981=rnorm(1:10),SEP_1981=rnorm(1:10),OCT_1981=rnorm(1:10),NOV_1981=rnorm(1:10),DEC_1981=rnorm(1:10))
# First attempt
DT[,TS_COL:=ts(.SD[,2:25,with=FALSE], start=c(1980,1), frequency=12)]
# Second
DT[,TS_COL:=ts(unlist(.SD[,2:25,with=FALSE]), start=c(1980,1), frequency=12)]
# Third
DT[,TS_COL:=list(list(list(ts(unlist(.SD[,2:25,with=FALSE]), start=c(1980,1), frequency=12))))]
我希望能够以这种方式访问特定行的ts对象(还没有运气):
DT[1,TS_COL]
...得到类似的东西(2年的月度数据):
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1980 2.13303849 0.74954206 -0.45112504 2.13558888 1.11883498 -0.39074470 1.77374480 -0.19513901 0.49920019 -1.12875185 0.45598049 1.97730211
1981 0.62764761 -0.86330094 -0.51585664 0.59677770 -0.71073980 -0.26208961 -0.38833227 1.39841244 -1.50490225 -0.72018921 1.06684672 0.07126184
有关如何实现这一点的任何提示？