general function for sorting a matrix

[Xah Lee]

hi, just a quick reply.

You are right, the python version i have is really terrible.

I'll look at your solution and possibly reply later.

Thanks for your code. It's great!

 Xah

On Aug 29, 9:40 am, Marc 'BlackJack' Rintsch <bj_... at gmx.net> wrote:
> On Wed, 29 Aug 2007 08:47:27 -0700,XahLeewrote:
> > While reviewing this code, there's something interesting of note.
>
> > Namely, in my perl solution, the approach is drastically different
> > than the python version. Instead ofsortingby looping thru the
> >sortingdirectives, it parses the directives then generate the
> > complete sort code, then eval it in one shot. This is more of a pure
> > functional approach.
>
> I don't see why that is more functional.  After all you iterate in both
> versions through the directives.  In Perl to build the code, in Python to
> sort the list multiple times.  Here's a Python function that sorts the
> list just once:
>
> def sort_matrix(matrix, directives):
>     tmp = [(column - 1, str if as_string else float, 1 if ascending else -1)
>            for (column, as_string, ascending) in directives]
>
>     def cmp_func(row_a, row_b):
>         for column, convert_func, factor in tmp:
>             result = cmp(convert_func(row_a[column]),
>                          convert_func(row_b[column])) * factor
>             if result:
>                 return result
>         return 0
>
>     matrix.sort(cmp=cmp_func)
>
> There's no return value as your reference implementation sorts in place
> too.
>
> Ciao,
>         Marc 'BlackJack' Rintsch