On Tue, Aug 12, 2008 at 07:48:54PM -0700, Alan Irwin wrote: > On 2008-08-11 21:39-0700 Alan W. Irwin wrote: > > > On 2008-08-11 22:09+0100 Andrew Ross wrote: > >> For example 21, some of the differences are just rounding errors. I do > >> however see some additional line at the end like. This is from plot3d. > >> I also see similar extra lines from the java and octave versions on a > >> different machine, so again I suspect a rounding error. > > > > I am going to have a look at ndiff > > (http://www.math.utah.edu/~beebe/software/ndiff/) which is advertised to > > ignore rounding errors. I will report back later on its suitability for > > our ctest needs. > > This project seems to be built with autoconf only so it has a nostalgic feel > (the latest release appears to be from 2000). The build, check, and install > were pretty straightforward, but I had to create $prefix/bin and > $prefix/man/man1 directories before the install would work properly for the > special install prefix I specified to the configure script. > > One of the ndiff command line options is to match lines if the relative > differences are less than some limit you specify. > > [snip] > > So from this you know there are some real structural differences between the > two files, and you get a nice summary of the maximum relative difference > that was less than 1.d-03 at the end which shows in this case that most > of the differences between the Tcl and C results are due to rounding. > > So ndiff may be an optional alternative to diff that we want to try for our > last ctest, but before we make that decision, I encourage the developers > here to try it since it is at least useful for quickly spotting real > differences between files which are ordinarily obfuscated by rounding > differences. > > BTW, ndiff is GPLed software. Andrew, there apparently is a name clash with > another Debian package called ndiff, but that sort of issue should be > solvable (say by adopting a variant of the name). Thus, I don't really > understand why this useful variant of diff has not been packaged for Debian.
Alan, Following your recommendation I also took a look at the sight. It certainly sounds useful for our purposes. I am tempted to add support for ndiff where available. A third test for examples with only small differences would be useful to sort out the real programming differences from the rounding errors. Andrew ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
