Re: [Bug-plotutils] ploututils testsuite failure on spline (i386)

[Robert S. Maier]

On 04/26/2016 07:27 AM, Gianfranco <address@hidden> wrote:

> Hi, I'm attaching the spline.test directory and the build log on 
Ubuntu yakkety i386
> (the default should be i686 now) thanks, Gianfranco

Gianfranco, thanks for the bug report on `spline' in plotutils. It's not 
at all serious, fortunately.

What's happening is this: the `make test' procedure for plotutils 
executes the `spline.test' script in the test directory, which runs the 
command

echo 0 1 0.5 0.75 -0.25 0 | ../spline/spline -a -T 1 -n 120 --precision 
5 -p >spline.out

The output file, spline.out, is then compared against the expected 
output, which is in the file spline.xout.  They don't exactly match on 
your system, which is why the test failed.

If you do a `diff spline.xout spline.out' to compare the two files, 
you'll see this:

1c1
< 0 0
---
> 0 -9.5518e-17
121c121
< 5 0
---
> 5 -9.5518e-17

The difference between -9.5518e-17 and zero (which are y-values 
generated by `spline', at the endpoints of an interpolatory range) is 
not a major one!

However, this ought to be fixed in the next release.  (This numerical 
bug appears on some systems but not on others, for unknown reasons; so 
the easiest way to deal with it would be to modify the test script 
`spline.test', to ignore the first and last lines when comparing 
spline.out with spline.xout.)

Best, Rob