"Save as" .dxf took nearly an hour for a 1.7MB vector .svg I created by doing Trace Bitmap of a .jpg scan that contained a lot of dirt/shadow noise along one side. I'm using 0.45.1-1.win32 on Vista Business on a Core2Duo 2GHz PC.

If it can't be made faster (ideally taking a couple of minutes rather than nearly an hour), I wish it could at least give a visible indication of its % progress. When it takes that long to make a .dxf and gives no indication of progress, one tends to assume inkscape is broken and kill it.

Thanks,

Craig in NJ

you should submit a bug/feature request about the .dxf speed Report a bug

Requests for progress bars have already been made, for tracing and exporting in particular. Heres the general one Ability to display progress bar

Looking at the script, I think I know why it's so appallingly slow (because I once made the same mistake in a Python script). It constructs the DXF file in memory as a string, building it by doing something like


over and over again. The trouble is that this operation copies string_so_far into a new string, which makes the overall process O(n^2) - which is fine if the output file is small, but incredibly slow for large output files.

The solution is to build the file as a list of strings, so that the basic operation is like


Then at the end they can be concatenated rapidly by


Please file a bug report, as prkos suggests. If I'm right about the problem, then the fix is trivial. (I've already made a patch, but I haven't tested it yet.)

No need to file a bug report now, as I've filed one myself: bug 199922.

The speed-up is now in the SVN trunk. (But it hasn't been added to the 0.46 branch, so it may not appear in a stable release until 0.47.)