| biject 2007-12-15, 6:56 pm |
| On Dec 15, 1:46 am, Klaus Stengel <Klaus.Sten...@asamnet.de> wrote:
.....
>
> Compression speed is also likely to be worse. In order to determine what
> prefixes have to be cut off in the splitting phase, one needs to search
> the smallest string repeatedly in the remaining part of the input
> buffer. I haven't made any benchmarks but judging from the structure of
> the algorithm, this "preprocessing" can become quite time intensive,
> especially with large block sizes and some decreasing sequence in the
> beginning of the input blocks (e.g. "987654321").
>
> Bye,
> Klaus
My first thought compression speed would be worse. My code is not
for speed. But here at two thoughts.
Each cycle in my way is unique. The case abcababc is treated as 1
on BWTS but 3 on in UNBTS and thats ok. Given strings from
separte cycles are different the compare function need only
compare till the difference is found. two since strings from
different
cycle are always different. Its only when string from same cycle can
a can two strings be identical and these will easer to deal with
since they would be shorter than buffer in most cases. My
current compare functions don't use this info so slower than could
be.
You could sort each cycle indepently and then merge the results
since the order of each row is sane within a cycle either from
big sort or seperate cyclle sorts. I chose the way I did for ease
of
understanding. Note sorting is at best an n log n time function a
string of 8 character 8*3 or time 24 a string of 16 would be 16*4
or 64 so 2 strings of 8 versus 1 string of 16 woulf be like
48 versus 64 I hope you get the point. The speed problem is
not settled.
David A. Scott
--
My Crypto code
http://bijective.dogma.net/crypto/scott19u.zip
http://www.jim.com/jamesd/Kong/scott19u.zip old version
My Compression code http://bijective.dogma.net/
**TO EMAIL ME drop the roman "five" **
Disclaimer:I am in no way responsible for any of the statements
made in the above text. For all I know I might be drugged.
As a famous person once said "any cryptograhic
system is only as strong as its weakest link"
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