请将此数据结构放入R中以重现我的示例：
dX <- structure(c(3272.1,3271.48,3281.03,3267.08,3260.65,NA,1616.3,1620.1,1639.9,1637.4,1669.6,1662.2,528.385,529.268,531.022,532.424,NA),.indexTZ = "",class = c("xts","zoo"),.indexCLASS = c("POSIXct","POSIXt"),tclass = c("POSIXct",tzone = "",index = structure(c(1345147200,1345406400,1345492800,1345579200,1345665600,1345752000),"POSIXt")),.Dim = c(6L,3L),.Dimnames = list(NULL,c("M1WO.Index","GC1.COMB.Comdty","JGAGGUSD.Index")))
现在试试这段代码：
library(PerformanceAnalytics) library(quantmod) library(timeSeries) charts.PerformanceSummary(R = dX)
并得到此错误：
Error in UseMethod("time<-") :
no applicable method for 'time<-' applied to an object of class "c('xts','zoo')"
我想这个问题是关于class = c(“xts,”zoo“)的数据,但是我不明白为什么它会以那种格式读取那些数据,我怎么能将它强制转换为一个简单的xts对象.
我怎么能解决这个问题？
我的系统：
R version 2.15.1 (2012-06-22) Platform: i386-pc-mingw32/i386 (32-bit) locale: [1] LC_COLLATE=English_United States.1252 [2] LC_CTYPE=English_United States.1252 [3] LC_MONETARY=English_United States.1252 [4] LC_NUMERIC=C [5] LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices datasets utils methods base other attached packages: [1] timeSeries_2160.94 timeDate_2160.95 [3] quantmod_0.3-17 TTR_0.21-1 [5] Defaults_1.1-1 PerformanceAnalytics_1.0.4.4 [7] xts_0.8-6 zoo_1.7-7 [9] rcom_2.2-5 rscproxy_2.0-5 loaded via a namespace (and not attached): [1] fBasics_2160.81 fGarch_2110.80.1 grid_2.15.1 lattice_0.20-6 [5] MASS_7.3-18 stabledist_0.6-4 tools_2.15.1
当我加载包时,我得到以下内容：
Loading required package: zoo Attaching package: ‘zoo’ The following object(s) are masked from ‘package:base’: as.Date,as.Date.numeric Loading required package: timeDate Attaching package: ‘timeDate’ The following object(s) are masked from ‘package:PerformanceAnalytics’: kurtosis,skewness Attaching package: ‘timeSeries’ The following object(s) are masked from ‘package:zoo’: time<-
根据错误信息,我猜这个问题来自于附加timeSeries和时间< - 被掩盖了来自package：zoo,我真的不知道它的含义以及如何处理.
解决方法
问题是package timeSeries.加载它会发出以下警告：
Attaching package: ‘timeSeries’
The following object(s) are masked from ‘package:zoo’:
time<-
您可以分离包以使用charts.PerformanceSummary而不是再次加载它：
detach('package:timeSeries')
detach('package:timeDate') # since it masks statistical functions
charts.PerformanceSummary(R = dX)
library(timeSeries)
