xts删除列名称

Question

I have a data.frame

res0 = structure(list(year = "2017", il = 11200000), .Names = c("year", 
"il"), row.names = c(NA, -1L), class = "data.frame")

however, when I try to make this an xts object I lose the column names.

as.xts(x = res0[,2:ncol(res0)], order.by = as.POSIXct(paste0(res0$year,"-01-01")), name = NULL)

This returns:

               [,1]
2017-01-01 11200000 

instead of

                 il
2017-01-01 11200000 

Answer 1

Subscripting in R drops dimensions by default. Use drop = FALSE to prevent this.

res0[, 2:ncol(res0), drop = FALSE]

Also note that this works to create an nx 1 zoo series with year as the index.

library(zoo)
z <- read.zoo(res0, FUN = c, drop = FALSE)