Re: FlatField.evaluate() returning missing

Hi Bill,

This change makes a lot of sense. It does not seem to have broken any of my applications. My only comment is that we may want to consider making the same change to Gridded3DSet, because it also does not strictly enforce non-zero coordinate signatures.

-Curtis

Bill Hibbard wrote:

Hi Cicero,

Nasdty bug here. Your application is constructing a
degenerate Gridded2DSet and the consistency test in
the Gridded2DSet constructor is not catching it.

Your createDomain() computes the same dx (and dy)
value for i=HALFDIM and i=HALDIM+1 (j=...). Thus your
grid has grid boxes with area = 0.

I've put a Gridded2DSet.java whose consistency test
catches this at:

 ftp://ftp.ssec.wisc.edu/pub/visad/untested/Gridded2DSet.java

Note that using a stricter test may break some applications
that have been getting away with constructing degenerate
grids. It is also possible that my new stricter test is
not formulated correctly - this stuff is quite complex.

So I hope the other VisAD developers may take a look at this
and test it (the changes are marked by 'CICERO' comments
in Gridded2DSet.java).

Good luck,
Bill