[Rd] example(smooth.spline) fails when function is NOT byte-compiled

[Prof Brian Ripley]

As the posting guide asked of you, try R-patched or R-devel before 
posting, and check the bug repository.

     • smooth.spline() used DUP = FALSE which allowed its compiled C
       code to change the function: this was masked by the default
       byte-compilation. (PR#14965.)


On 19/09/2012 21:41, Hervé Pagès wrote:
> Hi,
>
> example(smooth.spline) fails with the non byte-compiled version of the
> smooth.spline function:
>
>    > example(smooth.spline)
>
>    smth.s> require(graphics)
>
>    smth.s> attach(cars)
>
>    smth.s> plot(speed, dist, main = "data(cars)  &  smoothing splines")
>
>    [... more output deleted...]
>
>    smth.s> lines(smooth.spline(speed, dist, df=10), lty=2, col = "red")
>    Error in smooth.spline(speed, dist, df = 10) :
>      smoothing parameter value too small
>
> More precisely, here is what happens on a fresh R session (R-2.15.1
> configured with --disable-byte-compiled-packages):
>
>   ** Checking that smooth.spline() is not compiled:
>
>    > smooth.spline
>    [... output deleted...]
>    <environment: namespace:stats>
>
>   ** 1st call works:
>
>    > res <- smooth.spline(c(4, 4, 7, 7, 8, 9), c(2, 10, 4, 22, 16, 10))
>
>
>   ** 2nd call fails:
>
>    > res <- smooth.spline(c(4, 4, 7, 7, 8, 9), c(2, 10, 4, 22, 16, 10))
>    Error in smooth.spline(c(4, 4, 7, 7, 8, 9), c(2, 10, 4, 22, 16, 10)) :
>      smoothing parameter value too small
>
>   ** 3rd call (but now with the compiled version of the function) still
>      fails:
>
>    > library(compiler)
>
>    > smooth.spline2 <- cmpfun(smooth.spline)
>
>    > smooth.spline2
>    [... output deleted...]
>    <bytecode: 0x16813a0>
>    <environment: namespace:stats>
>
>    > res2 <- smooth.spline2(c(4, 4, 7, 7, 8, 9), c(2, 10, 4, 22, 16, 10))
>    Error in smooth.spline2(c(4, 4, 7, 7, 8, 9), c(2, 10, 4, 22, 16, 10)) :
>      smoothing parameter value too small
>
> Thanks,
> H.
>
> My session info:
>
>  > sessionInfo()
> R version 2.15.1 (2012-06-22)
> Platform: x86_64-unknown-linux-gnu (64-bit)
>
> locale:
>   [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
>   [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
>   [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
>   [7] LC_PAPER=C                 LC_NAME=C
>   [9] LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] compiler  stats     graphics  grDevices utils     datasets  methods
> [8] base
>
> loaded via a namespace (and not attached):
> [1] tools_2.15.1
>
>


-- 
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