XTS replacement error NextMethod(.Generic) : number of items to replace

问题

I'm struggling with xts right now... I have an XTS object, and I am trying to replace a specific date's data with a new set, but I keep running into issues of replacement length, even though I am certain they are the same and no missing data. Any ideas?

I made a dummy example to demonstrate my issues:

R> test1 = xts(cbind(trade_level = 1, t2 = 3),order.by=as.Date("1991-01-02"))
R> test2 = xts(cbind(trade_level = 5, t2 = .053),order.by=as.Date("1991-01-02"))
R> first_day = "1991-01-02"
R> test1[first_day] = test2
Warning message:
In NextMethod(.Generic) :
  number of items to replace is not a multiple of replacement length
R> sessionInfo()
R version 3.0.1 (2013-05-16)
Platform: x86_64-w64-mingw32/x64 (64-bit)

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] reshape2_1.2.2  xts_0.9-7       zoo_1.7-10      ggplot2_0.9.3.1

loaded via a namespace (and not attached):
 [1] colorspace_1.2-4   dichromat_2.0-0    digest_0.6.4       grid_3.0.1        
 [5] gtable_0.1.2       labeling_0.2       lattice_0.20-23    MASS_7.3-29       
 [9] munsell_0.4.2      plyr_1.8           proto_0.3-10       RColorBrewer_1.0-5
[13] scales_0.2.3       stringr_0.6.2      tools_3.0.1

回答1:

That's a warning, not an error. And it gives you a hint about what's wrong... you need to add a comma to specify that you want to replace all columns.

test1 = xts(cbind(trade_level = 1, t2 = 3),order.by=as.Date("1991-01-02"))
test2 = xts(cbind(trade_level = 5, t2 = .053),order.by=as.Date("1991-01-02"))
first_day = "1991-01-02"
test1[first_day,] = test2

But don't blame xts, this is how the matrix class works:

test1 = xts(cbind(trade_level = 1, t2 = 3),order.by=as.Date("1991-01-02"))
test2 = xts(cbind(trade_level = 5, t2 = .053),order.by=as.Date("1991-01-02"))
m1 <- as.matrix(test1)
m2 <- as.matrix(test2)
m1[1] <- m2   # warning
m1[1,] <- m2  # works

来源：https://stackoverflow.com/questions/23768007/xts-replacement-error-nextmethod-generic-number-of-items-to-replace

标签

xts