[R] Error: Cannot Coerce POSIXt to POSIXct when building package

[Prof Brian Ripley]

On Wed, 8 Aug 2007, Praveen Kanakamedala wrote:

> A newbie here - please forgive me if this is a basic question.  We have an
> in house package built in R 2.2.1 (yes we're a little behind the times at
> our firm)and would like to rebuild it using R 2.5.1.  However, when I try
> and build the package from source, I keep getting this error:
>
> Error in as(slotVal, slotClass, strict = FALSE) :
>        no method or default for coercing "POSIXt" to "POSIXct"
> Error : unable to load R code in package 'Mango'
> Error: package/namespace load failed for 'Mango'
>
>
> I tried defining a new method "as.POSIXct" in the package to coerce POSIXt
> to POSIXct and then added the as.POSIXct method to the "NAMSPACE" file.  The
> build still doesn't work (I get the same error message). Any idea what I am
> doing wrong? The coercion statement looks like this and works in R GUI:

How did you get this?  There should be no objects of class 'POSIXt' alone, 
and I get e.g.

> now <- Sys.time()
> as(now, "POSIXct")
Error in asMethod(object) : explicit coercion of old-style class (POSIXt, 
POSIXct) is not defined

That can be fixed (see ?as), but you seem to have a malformed object in 
one of your slots.

As often applies,

> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



> #from is a vector of dates in the format "%d-%b-%Y")
> from <- as.POSIXct(strptime(from, format = "%d%b%Y"), tz = "GMT")
>
> Here is my environment info:
>
> R version 2.5.1 (2007-06-27)
> i386-pc-mingw32
>
> locale:
> LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United
> Kingdom.1252;LC_MONETARY=English_United
> Kingdom.1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
>
> attached base packages:
> [1] "tcltk"     "stats"     "graphics"  "grDevices" "utils"     "datasets"
> "methods"   "base"
>
> other attached packages:
>  fSeries      nnet      mgcv   fBasics fCalendar   fEcofin   spatial
> MASS
> "251.70"  "7.2-34"  "1.3-25"  "251.70"  "251.70"  "251.70"  "7.2-34"  "
> 7.2-34"
> I would sincerely appreciate any help.
>
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>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595