Recent changes to 444: option for "set fit" to change MAX_DATA

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Fri, 13 May 2016 17:29:34 -0000

status: pending-accepted --> closed-fixed

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Fri, 13 May 2016 17:29:08 -0000

OK. Done.

#444 option for "set fit" to change MAX_DATA

Ethan Merritt — Fri, 13 May 2016 17:23:11 -0000

Sure. Might as weel go into 5.0 also. I don't see any down-side.

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Fri, 13 May 2016 14:12:31 -0000

status: open --> pending-accepted
Group: -->

#444 option for "set fit" to change MAX_DATA

Hans-Bernhard Broeker — Tue, 10 May 2016 18:10:26 -0000

Well, as it is, 2048 data points already eat more than 64 KiB, what with there being 6 arrays of at least 2048 doubles if you go there. That's 96 KiB, and yes, that quite hard to support for a 16-bit platform, which was still supported back then.

And there's a reason why the factor is 1.5 instead of 2, too. Back when that factor was set (by myself, IIRC), the maths part would allocate a matrix of (num_data * num_data) elements, so a growth by 2 would actually increase the memory usage by a factor of 4. So I chose 1.5, which yields an effective resize of 2.25. The underlying solver has changed in the meantime, so memory consumption is now linear in num_data. That means a factor of 2 would be sensible now.

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Tue, 10 May 2016 16:25:39 -0000

Here's the equivalent code section from plot2d.c:

    while ((j = df_readline(v, max_cols)) != DF_EOF) {

        if (i >= current_plot->p_max) {
            /* overflow about to occur. Extend size of points[]
             * array. Double the size, and add 1000 points, to avoid
             * needlessly small steps. */
            cp_extend(current_plot, i + i + 1000);
        }

No message whatsoever. Plus a more "agressive" extension 2*n+1000 instead of (n*3)/2.
I propose to adopt the code in fit.c accordingly.

#444 option for "set fit" to change MAX_DATA

Karl Ratzsch — Tue, 10 May 2016 16:16:55 -0000

I guess something like 64k would be a sensible change to the default of MAX_DATA = 2048. I cannot ascertain if it would be hard to do this in a dynamic fashion. plot does not have a hard-set limit, so it should be possible, i guess.

#444 option for "set fit" to change MAX_DATA

Karl Ratzsch — Tue, 10 May 2016 16:12:50 -0000

Coincidentally, I discovered that post half an hour ago and am currently installing msys2. :-)

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Tue, 10 May 2016 16:09:04 -0000

Btw. thanks to MSYS2/Mingw64 compilation is now almost as pain-free on Windows as it is on *nix, see [support-requests:#199].

#444 option for "set fit" to change MAX_DATA

Bastian Märkisch — Tue, 10 May 2016 16:04:47 -0000

These limits look like they come from an age when 64kB were a lot... Couldn't we just eliminate this warning/info message - or at least only emit it for really sizeable datasets?