chron blues

Peter Dalgaard BSA writes:

Bernie McConnell <bm8 at st-andrews.ac.uk> writes:

GoodDay,

Could someone please tell me why b (below) does not return a vector of 10
chron objects?  Hopefuly I am being remarkably naive or have missed
something obvious in the chron documentation.  I'm running Win NT 4.0

I don't think you're particularly naive...
The root of this seems to be this

Browse[1]> unclass(e1)+c(1.5,1.5)
[1] 3658.5 3658.5
Browse[1]> unclass(e1)+c(1.5)
[1] 3658.5
attr(,"format")
[1] "d/m/y" "h:m:s"
attr(,"origin")
month   day  year 
    1     1  1970 

This is a generic issue, recycling kills attributes:

x<-1
attr(x,"foo")<-"bar"
x+1

[1] 2
attr(,"foo")
[1] "bar"

x+1:2

[1] 2 3

I forget whether there's a logic to this, but S-Plus 3.4 is doing the
same thing. Hence, Ops.dates inside chron probably needs fixing.
Specifically at the line

   val <- NextMethod(.Generic)

(original problem:)

library(chron)
gps.start.date <<- chron("06/01/80",

+                         "00:00:00",  
+                         format=c("d/m/y","h:m:s"))

..

<bold>> b <<- gps.start.date + rep(1.5,10)