[R-pkg-devel] Excessive time of first example to be checked

[Jean-Matthieu Monnet]

I was asked by CRAN to fix NOTEs in the new version of the package lidaRtRee

On Debian 
(https://win-builder.r-project.org/incoming_pretest/lidaRtRee_4.0.0_20220520_163049/Debian/00check.log) 
I have one note related to the maintainer :

# -----
* checking CRAN incoming feasibility ... NOTE
Maintainer: ‘Jean-Matthieu Monnet <jean-matthieu.monnet using inrae.fr>’
# ------

On Windows I also have another NOTE 
(https://win-builder.r-project.org/incoming_pretest/lidaRtRee_4.0.0_20220520_163049/Windows/00check.log) 
due to to the running time of the first example, which is my main concern.

# ------
* checking examples ... [78s] NOTE
Examples with CPU (user + system) or elapsed time > 10s
              user system elapsed
aba_metrics 11.79   0.27   12.05
# ------

I do not have access to a windows machine for testing. On my machine 
(Ubuntu 20.04) the example runs in ~ 4 sec after R startup, but in less 
than 2 sec on the following calls (see details below). I am not sure if 
  the excessive running of this example (which is the first to be 
tested) is due to library loading. If it is the case, how can I fix it:
- create a "virtual" example which purpose would be to just load 
libraries, hoping that its running time would be less that 10 sec.
- load libraries at start up using a different way.
- ... ?

Here is a link to the package tar.gz 
(https://filesender.renater.fr/?s=download&token=163ca058-13ba-4cf5-8f4f-3514abd03ff8) 
and below the code I run on my machine to estimate the example time.


# --------------
# install package
# install.packages(file.choose(), repos=NULL)
#
# --------------
# running time at first call
system.time(example(aba_metrics, package = "lidaRtRee"))
# Le chargement a nécessité le package : lidR (loading required)
# lidR 4.0.1 using 6 threads. Help on <gis.stackexchange.com>. Bug 
report on <github.com/r-lidar/lidR>.
#
# [...]
# utilisateur     système      écoulé
# 3.867       0.095       3.742
#
# --------------
# running time at next call
system.time(example(aba_metrics, package = "lidaRtRee"))
#
# [...]
# utilisateur     système      écoulé
# 0.182       0.000       0.082

Thank you very much for your answers.


-- 
Jean-Matthieu Monnet
UR LESSEM - INRAE Grenoble