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Author fast'ish BWT source code
houston

2006-09-03, 6:55 pm

Hi; very new here so be kind lol...

Can anybody point me in the direction of a simple yet relatively fast
BTW algorithm in C that does not change the values of the bytes to
other values.. Been using MSufSort.2.2 for a few days and it is
extremely impressive. Thing is it changes the values of the bytes? I
need a BWT that does not modify the byte values but again does not use
a slow qsort...!



any help appreciated.

Graham.

michael

2006-09-03, 9:55 pm

You have the alternative sort order macro enabled. This is why you are
not
seeing the same symbols as the source string. Comment out the macro
defined near
the top of MSufSort.h which reads ...

#define USE_ALT_SORT_ORDER

and you will see the BWT with the same symbols as the source string.

- Michael A Maniscalco



houston wrote:
> Hi; very new here so be kind lol...
>
> Can anybody point me in the direction of a simple yet relatively fast
> BTW algorithm in C that does not change the values of the bytes to
> other values.. Been using MSufSort.2.2 for a few days and it is
> extremely impressive. Thing is it changes the values of the bytes? I
> need a BWT that does not modify the byte values but again does not use
> a slow qsort...!
>
>
>
> any help appreciated.
>
> Graham.


houston

2006-09-04, 6:55 pm

Excellent... I never wanted to use another BWT program I think MSufSort
will be a hard program to beat with regards to speed.. thanks for the
advice I'll do that now!..


Graham.

michael wrote:[color=darkred]
> You have the alternative sort order macro enabled. This is why you are
> not
> seeing the same symbols as the source string. Comment out the macro
> defined near
> the top of MSufSort.h which reads ...
>
> #define USE_ALT_SORT_ORDER
>
> and you will see the BWT with the same symbols as the source string.
>
> - Michael A Maniscalco
>
>
>
> houston wrote:

michael

2006-09-04, 6:55 pm

There are other fast ones too.

DivSufSort and Archon come to mind. In fact, Archon is faster in many
cases
but it does have a really bad worst case on some strings.

- Michael


houston wrote:[color=darkred]
> Excellent... I never wanted to use another BWT program I think MSufSort
> will be a hard program to beat with regards to speed.. thanks for the
> advice I'll do that now!..
>
>
> Graham.
>
> michael wrote:

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