On Tuesday, 21 January 2014 at 10:05:42 UTC, terchestor wrote:
I'm a newcomer to D language (after years of programming with
ASM Motorola 68030-40 long time ago, as well as C, C++,
Javascript, PHP, etc.), but not anymore a professional coder.
After reading some articles around there and that nice and cute
TDPL (just after Coding standards, another world!), I began to
write some to exercise my fresh new "skill".
I choose as a first experience, to write a simple class
implementing a very interesting random number generator known
as Tausworthe, according to the recipe found in this paper:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.101.9723&rep=rep1&type=pdf.
The algorithm in C is quite simple and set in Lecuyer's paper
as:
unsigned long s1, s2, s3, b;
double taus88 ()
{
/* Generates numbers between 0 and 1. */
b = (((s1 << 13) ^ s1) >> 19);
s1 = (((s1 & 4294967294) << 12) ^ b);
b = (((s2 << 2) ^ s2) >> 25);
s2 = (((s2 & 4294967288) << 4) ^ b);
b = (((s3 << 3) ^ s3) >> 11);
s3 = (((s3 & 4294967280) << 17) ^ b);
return ((s1 ^ s2 ^ s3) * 2.3283064365e-10);
}
I made some "adjustments" to this algorithm, to yield either a
(long) integer or (double) float result, in any range.
Benchmarks
----------
Tausworthe module (rdmd -main -unittest
-debug=Benchmark_Tausworthe tausworthe.d)
============================================================
Call 1_000_000 times benchmark_uniform_ulong( ): 30 ms |
Average : 3e-05 ms
============================================================
============================================================
Call 1_000_000 times benchmark_uniform_double( ): 42 ms |
Average : 4.2e-05 ms
============================================================
============================================================
Call 1_000_000 times benchmark_uniform_std( ): 70 ms | Average
: 7e-05 ms
============================================================
Comparing ratio tausworthe / std.random: 0.609229
I'd greatly appreciate any reviewing and testing of my code.
Any improvements you feel necessary are most welcome (as said
before, I'm a newbie).
What's the best place to publish the code?
Github, bitbucket or equivalent.
If you think it's ready for general use then write a dub.json and
register it to code.dlang.org
Take care with modifying random number generators, it's quite
easy to ruin them by changing something that seems innocent.
