[R] unexpected behaviour of an extended time series (using packages spuRs and xts)

[Olivier ETERRADOSSI]

Hi list,



I thought I knew how to use extended time series (package xts), but I was
wrong  J  …



While preparing a toy example for something else, using data provided in
R, I run into an unexpected problem and can’t figure by myself what is
happening below, can anyone of you tell ? I searched the archives but
didn’t locate any answer. Probably it’s trivial, so please forgive  :



I’m using :

R version 3.2.3 (2015-12-10) -- "Wooden Christmas-Tree" / Platform:
x86_64-w64-mingw32/x64 (64-bit)

Packages are updated weekly, sometimes daily.



I take some data from package spuRs :

> library(spuRs)

> data(kew)



I turn the dataframe into time series (by combining each kew[,2:13] one
after each other into a vector, and turning the vector into time series).



One is ts :



>
kew.ts<-ts(data=stock,start=kew$year[1],end=kew$year[length(kew$year)],fre
quency=12)



And the other is xts, it looks fine at first :



> kew.xts<-as.xts(kew.ts)

> periodicity(kew.xts)

Monthly periodicity from janv. 1697 to janv. 1999  # OK

> hist(kew.xts) # OK

> summary(kew.xts)

     Index         kew.xts

 Min.   :1697   Min.   :  0.00

 1st Qu.:1772   1st Qu.: 29.70

 Median :1848   Median : 47.00

 Mean   :1848   Mean   : 51.14

 3rd Qu.:1924   3rd Qu.: 67.60

 Max.   :1999   Max.   :189.00  # OK



> gdata::is.what(kew.xts)

[1] "is.array"        "is.atomic"       "is.double"
"is.index.unique"

[5] "is.matrix"       "is.numeric"      "is.object"       "is.regular"


 [9] "is.time.unique"  "is.unsorted"     "is.xts"          "is.zoo"
# seems OK





# But now, first try :

> plot(kew.xts)

Error in if (on == "years") { :

  valeur manquante là où TRUE / FALSE est requis     # french for «
missing value where TRUE/FALSE is required »



# hmmmm, let’s try something else :

> plot(kew.xts['1697-01/1979/']) # OK



> plot(kew.xts['1697-01/1980/'])

Error in if (on == "years") { :

  valeur manquante là où TRUE / FALSE est requis



> plot(kew.xts['1697-01/1979-12/']) # OK



> plot(kew.xts['1697-01/1980-01/'])

Error in if (on == "years") { :

  valeur manquante là où TRUE / FALSE est requis



# but…!  :



> plot(kew.xts['1979-01/1980/']) # OK !!!!!



And so are :

> plot (kew.xts['1978/1980/'])

> plot(kew.xts['1977/1982/'])

> plot(kew.xts['1977-01/1982-12'])  # and so on…



I’m puzzled ! I have probably missed a trivial point… Can someone tell ?



Thanks a lot list, regards, Olivier



--------------------------

Olivier ETERRADOSSI

Maître-Assistant, HDR

Ecole des Mines d’Alès (C2MA, site de Pau)

Ingénierie de l'aspect visuel et tactile des matériaux

Pôle « Recherche sur les Interactions des Matériaux avec leur
Environnement » (RIME)

Hélioparc, 2 av. P. Angot, F-64053 PAU CEDEX 9

Tel : 05 59 30 90 35 (direct) - 05 59 30  54 25 (std)

Fax : 05 59 30 63 68

 <http://www.mines-ales.fr/> http://www.mines-ales.fr

 <http://www.mines-telecom.fr/> http://www.mines-telecom.fr








	[[alternative HTML version deleted]]