[Radiance-general] Research tools: who what which how?

[Christopher Rush]

Schorsch, Thanks! Precisely the type of response I was trying to poke for. I threw something together in a few minutes from a quick google search just to steer the conversation. I certainly didn't do much quality comparison, and zero thinking about if any of these are really the right way to do it. My primary note is that we can debate the optimal, but the collective mental barriers and user-group predisposition, and size or quality of searchable online resources should be considered. I'm not the best person to consider them since I have very little depth in any language, but just noting to keep novices like me in mind. I honestly don't know if those make a case for any one language, but I felt compelled to add my two cents - since everyone else was talking about APIs which I have no concern for.

I always wish that threads like this one gave me more definitive suggestions for putting more effort in any one language (which, of course, is asking too much!).




-----Original Message-----
From: Georg Mischler [mailto:schorsch at schorsch.com] 

Somewhat off-topic, but...

Out of curiosity, I played around with those examples a bit.
I had to slightly modify all of them, first to get Perl and Ruby to run
at all, and then to make sure all of them produce tabs instead of 
spaces.
Btw: The Perl version adds an extra tab at the end of each line.


perl -anF'\t|\n' -e'$n=@F-1 if \!$n;for(0..$n){push@{$$m[$_]},$F[$_]} 
END{print map{join"\t",@$_,"\n"}@$m}'

python -c "import sys; print('\n'.join('\t'.join(c) for c in 
zip(*(l.split() for l in sys.stdin.readlines() if l.strip()))))"

ruby -e 'puts readlines.map(&:split).transpose.map(){|x|x*"\t"}'


The result shows (as expected) that this kind of comparison is utterly
meaningless. There are simply too many factors out of your control
that can influence the result. Between Perl and Python, the
executables that happen to be installed on my box pretty much get the
opposite result than you reported. Maybe my Python is in better shape
than yours, because it gets more exercise... ;)

I'm actually a bit surprised by the bad performance of Perl. One of
the reasons may be the suboptimal algorithm, which explicitly loops
through the data in the interpreter. The other two use a functional
approach, where the heavy lifting is handled in C. Ruby has a slower
startup time, but its operating performance is much closer to Python.
I also didn't expect that much of a speed-up with Python 3 over 2.

The Python version is easy to understand, once you know that the
builtin function zip() is equivalent to Rubys transpose(). The rest
is IO and string manipulation. You also may not be familiar with
generator expressions. Very powerful stuff!


150 Kb  (160 x 160 matrix)

0.2  perl 5
0.1  python 2.7
0.02 python 3.4
0.4  ruby


6 Mb  (1000 x 1000 matrix)

1.02  perl 5
0.36  python 2.7
0.22  python 3.4
0.48  ruby 2.1


24 Mb  (2000 x 2000 matrix)

4.11  perl 5
1.74  python 2.7
1.13  python 3.4
2.41  ruby 2.1


Cheers
-schorsch


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