Sane

So what was this for anyways?

DaWei

Pattern recognition. This is one of those cases where abstraction can't be afforded, unfortunately, because of the large number of operations. I need to go off and redesign the microprocessor. Incidentally, involving the center square is a substantial penalty, performance-wise.

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Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code.
Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Sane

Oh, so your request for a "Python" solution was a request for an efficient solution? I'm searching your post for any hints of sarcasm. Oh well. I guess you went with hydroxide's then.

DaWei

There's no sarcasm there. None of the solutions given is effective. I'm a fan of abstraction. Elegance and clarity. Women and scotch. Sometimes they just don't happen to woik out.

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Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

hydroxide

Ok - some questions/thoughts:
* Is it necessary to have your structure as a list of lists?
* What about a flat list? 3*y + x gives the index for a flat list, which saves you a lookup. (is y+y+y+x faster??)
* If using a flat list, you reuse the list with g[:] = [...] which IIRC is more efficient than creating a new list.
* What about a dict? Complex numbers can function as points (0+0j, 0+1j,..., 2+2j) - assuming that they're compiled in.
* How tight is memory? Can you have four lookup tables and just switch the table based on the rotation? If rotation is a frequent operation, the tradeoff might be worthwhile. The lookup tables would point to indices of a flat list.
*For rotation using a flat list, if you have a dummy member at the end you could use multiplication and slicing:
* Timing things is left as an exercise... ;-P

-T.

DaWei

Thanks for the exercise . In the reality of this usage no lookups or tricks or maps or sich be necessary. Flat is the way to go, of course, unless I whup up me a special set of hardware. The positional movements for a 90-degree rotation and for a mirror are fixed. I was just curious, again, what abstraction would cost.

__________________
Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code.
Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers