On Mon, Feb 22, 2010 at 09:37:33AM -0600, Maurice LeBrun wrote:
> On Monday, February 22, 2010 at 14:42:57 (+0000) Andrew Ross writes:
>  > 3) Talking of efficiency, I worry that this introduces a large additional 
>  > level of complexity for a rather specialist set of cases where odd data 
>  > storage methods are used. I am slightly relieved by David's comments, 
>  > but I would like to have a thorough comparison of the time difference.
>  > This should include a "large data" case as well where timings might be
>  > more important. The lena image might be one suitable case. The test 
>  > should also multi-language tests to see if not copying large amounts
>  > of data around is quicker than having lots of callbacks.
> 
> I see this issue as mostly about program clarity & programmer convenience.
> Nothing wrong with a test, but I'll restate (and elaborate upon) my previous
> prediction that efficiency is mostly a moot point.  Of course those with
> scientific programming backgrounds will tend to see function calls associated
> with a single data point as somewhat evil, and they'd be right -- in the high
> performance arena of say, the central processing loops of a multidimensional
> simulation.  But that's not the situation here.  Aside from the oddball case
> of plotting into a memory buffer, at the end of the call chain some i/o will
> be performed.  That should dwarf the function call overhead.

Maurice,

You are almost certainly right for the current plplot examples, none of which
use large arrays. What I worry about just a little is things like contouring
a very large 2-d array where there is a lot of data and a fair bit of array 
accessing. I'd just like to be satisfied that there is no impact before
such a large and intrustive change is made. I'm sure it is just a scientific
programming prejudice...

Andrew

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