From: Andrew R. <and...@us...> - 2010-02-22 15:56:34
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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 |