Re: FlatField.evaluate() returning missing

• To: Cicero Augusto Wollmann Zandoná <cicero@xxxxxxxxxx>
• Subject: Re: FlatField.evaluate() returning missing
• From: Bill Hibbard <billh@xxxxxxxxxxxxx>
• Date: Mon, 5 Sep 2005 18:26:35 -0500 (CDT)

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

• Follow-Ups:
  • Re: FlatField.evaluate() returning missing
    • From: Cicero Augusto Wollmann Zandoná
  • Re: FlatField.evaluate() returning missing
    • From: Curtis Rueden

• References:
  • Re: FlatField.evaluate() returning missing
    • From: Cicero Augusto Wollmann Zandoná