I’ve installed R-2.8.1
Can’t find a ncdf – package which is up to date.
Suggestions?

- I download from web into a local copy
- I comment out the download.file(…) line
and do all further tests from the local copy.
#
# I’ve already had epiriences with folks,
# trying to get a script working, acessing
# a ftp server in a production environment.
#
# They did work parallely on two scripts,
# accessing the same server and several
# folders, at the peaktime of production
# and they did bulk downloads.
#
# These guys did drive me mad.
#
# So, guys, let’s be nice. Even
# system engineers/system administrators are
# – in general – plain humans. Let’s avoid
# to harm them too much.
#
# — first test run, example:
#
url=”http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv”
IARCfile=”H:\\DB\\DAILY\\IARCplot.csv”
download.file(url,IARCfile,mode=”wb”,cacheOK=TRUE)
IARCbuffer=readLines(IARCfile)
#
# — all further test runs, example:
url=”http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv”
IARCfile=”H:\\DB\\DAILY\\IARCplot.csv”
#——-download.file(url,IARCfile,mode=”wb”,cacheOK=TRUE)
IARCbuffer=readLines(IARCfile)
#

It did remind me, to take a look on R.
- I had the intention already for quite
some time, but did delay it due to
other requests.
- I’ve installed it a few days ago,
I do now create/install scripts
for all my frequently downloads.

Yeez, now I silly myself for not using it sooner.
Would have done some things much easier.

What I do like mostly, is the RODBC package,
because I usually do store all data in a database.

I had already some occurences where some things
didn’t work the way they should – according to the
manuals. Nevertheless, I found ways to got it
running.

*Would you mind, if I do entries here on my
expiriences – what didn’t work – and how to
get it working?

I’m usually doing it on Win2k, WinXP, Win2003 Server,
so my solutions are only reated th these platforms.

KlausB

Another free toolbox that looks interesting is NIST Dataplot (http://www.itl.nist.gov/div898/software/dataplot/).

It then talked at length about how high level R is and that it is extensible.

Seems pretty levelheaded to me.

Realistically, with low-level languages (C and FORTRAN are low-level compared to R or MATLAB), the difference in performance comes down to compiler ability. FORTRAN is generally assumed to be simpler for a programmer to write when producing scientific code, but that does not indicate any inherent performance gain, though it may allow more efficient code which is easier for a compiler to optimize. However, compilers do display an amazing ability to “fix” bad code (though not always), which likely becomes progressively more difficult as the language becomes more abstract.

That said, when I write speed critical code, I use neither canned library functions nor C-code, but instead rely on hand optimized assembly. This is slow and painful, but ultimately allows me to fine tune performance. There’s a balance between best code for set of instructions and cache access efficiency when looping on the same instructions. What works best is not always obvious by inspection alone, either – sometimes I beat the compiler and sometimes it beats me – but writing the code in the lowest level possible (assembly or machine) nearly always provides the best performance.

Mark