Which sparse matrix package?

[James Mills]

On Fri, Dec 19, 2008 at 10:49 AM,  <mmanns at gmx.net> wrote:
> On Fri, 19 Dec 2008 08:33:28 +1000
> "James Mills" <prologic at shortcircuit.net.au> wrote:
>
>> > The dict that I tried out is of the type:
>> >
>> > {(1,2,3): "2323", (1,2,545): "2324234", ... }
>> >
>> > It is too slow for my application when it grows. One slicing
>> > operation with list comprehensions takes about 1/2 s on my computer
>> > for 1E6 elements.
>>
>> Let me get this straight.
>> It's taking 0.5s to slice your matrix
>> of 1E7 (10000000.0 rows/columns)
>
> My benchmark is as follows:
>
> 1) Each of the numbers in the 3-tuple is in the range [0, 1E7).
> 2) There are 1 000 000 elements in the dict (randomly distributed).
> 3) The content string is a random number in the range [0, 1E10) that is
> casted into a string.
> 4) Measure the time that retrieving all elements in a 10000x100x10 cube
> requires.

Does a spreadsheet really get this complex ?

>> Are you mad ? This is TEN Millions and you
>> required it faster than 0.5s ?
>
> Think about how often a spreadsheet re-calculates cells.
> Furthermore, people tend to copy&paste cells.
>
> I had some small example (Wagner-Whitin algorithm demo)
> with hundreds of slicing operations on one screen. I believe that
> no-one wants to wait for 1/2 s times 500 == 250 s each time the
> spreadsheet is updated.

Hmmm