翻译I am finding differences in behavior between two environments running R 2.12.1. In the first one zoo behaves as expected.
> library(zoo) > x.date <- as.Date(paste(2003, 2, c(1, 3, 7, 9, 14), sep = "-")) > x <- zoo(rnorm(5), x.date) > index(x) [1] "2003-02-01" "2003-02-03" "2003-02-07" "2003-02-09" "2003-02-14" > as.Date(index(x)) [1] "2003-02-01" "2003-02-03" "2003-02-07" "2003-02-09" "2003-02-14" > sessionInfo() R version 2.12.1 (2010-12-16) Platform: x86_64-unknown-linux-gnu (64-bit) locale: [1] C attached base packages: [1] grid stats graphics grDevices utils datasets methods base other attached packages: [1] ggplot2_0.8.9 proto_0.3-9.1 reshape_0.8.4 MASS_7.3-9 plyr_1.4 RODBC_1.3-2 zoo_1.6-4 loaded via a namespace (and not attached): [1] lattice_0.19-13 tools_2.12.1In the other I get the following output:
> library(zoo) > x.date <- as.Date(paste(2003, 2, c(1, 3, 7, 9, 14), sep = "-")) > x <- zoo(rnorm(5), x.date) > index(x) [1] "02/01/2003 00:00:00.000 UTC" "02/03/2003 00:00:00.000 UTC" "02/07/2003 00:00:00.000 UTC" "02/09/2003 00:00:00.000 UTC" "02/14/2003 00:00:00.000 UTC" > as.Date(index(x)) [1] "02/01/2003 00:00:00.000 UTC" "02/03/2003 00:00:00.000 UTC" "02/07/2003 00:00:00.000 UTC" "02/09/2003 00:00:00.000 UTC" "02/14/2003 00:00:00.000 UTC" > sessionInfo() R version 2.12.1 (2010-12-16) Platform: x86_64-unknown-linux-gnu (64-bit) locale: [1] C attached base packages: [1] grid grDevices graphics stats datasets utils methods base other attached packages: [1] zoo_1.6-4 ggplot2_0.8.9 proto_0.3-8 reshape_0.8.4 plyr_1.4 loaded via a namespace (and not attached): [1] digest_0.4.2 lattice_0.19-13Not only is it odd, but the latter behavior results in an error message from ggplot2. Any insights? Thanks in advance.