Re: gnuplot slow on BIG files

[Hans-Bernhard B. <br...@ph...>]

Daniel J Sebald wrote:
> Hans-Bernhard Broeker wrote:

>> Necessity is not the issue --- convenience of maintaining the overall 
>> structure of a very ancient code base is.  The code has always been 
>> organized to read all data, then let the "every" filter decide which 
>> points to actually use.

> Actually, from what I remember, in datafile.c the "everypoint" variable 
> is used to toss out points.  

Yes.  But the question is: *when* does that happen: before sscanf()ing
the values, or afterwards?  After a quick look into the current sources,
it would seem that at least for 'matrix' files, it reads the entire 
thing before applying 'every'.  That's probably the reason why 'every 
500:500' didn't achieve any speedup for Dimitrios.