[visit-users] how to set default NaN in VisIT?

ashutosh singh ashutoshsingh.ashu at gmail.com
Thu Mar 25 07:02:45 EDT 2010


Hi Alex,

Try Volume plot to blank out completely the cells out of min and max. Do not
forget to change the rendering method from splatting to 3D texturing in the
volume plot plotatts. And use slices as 10000 and number of samples as
maximum.

I hope you will get the desired visualization.

On Thu, Mar 25, 2010 at 11:53 AM, Alex Hoffmann <ah519 at cam.ac.uk> wrote:

> Hi,
>
> Many thanks for your answers.
>
> I could use a minimum threshold, but displaying undefined values with
> the minimum rather than blanking them out is not very clean and makes
> interpretation more difficult.
>
> I am not sure if I follow you with the ghost cells/values.  I did skim
> through the official VisIt documentation and could not find any further
> entries on the topic (except for the InverseGhostZone operator).  I am
> running an atmospheric model and I do have full control over the code
> and netCDF output generation.  My data arrays have a _FillValue
> attribute that specify the undefined value; did you mean to say I have
> to write another attribute to the arrays or a global attribute to the
> header named ghost cells (or which would be the exact name)?  Where do
> you switch these on and off?
> Would I have to write another data reader?
>
> Thanks again, best wishes,
>
> Lex
>
> Hank Childs wrote:
> > Hi Alex,
> >
> > I agree with Ashutosh that ghost values would do great here.  However,
> > I suspect you are running a climate code and that you don't have
> > control over the data output.
> >
> > I ran into this issue as well a few weeks ago and I think that VisIt
> > needs a better solution.
> >
> > In the interim, you can:
> > 1) bring up the Plot Atts->Pseudocolor window.
> > 2) Turn on the min flag.
> > 3) Set the min to "0" (or whatever an appropriate min is)
> > 4) Click Apply.
> >
> > Unfortunately, this solution requires you to (1) know what the minimum
> > is and (2) some extra work on your behalf.
> >
> > Best regards,
> > Hank
> >
> > On Thu, Mar 25, 2010 at 2:21 AM, Alex Hoffmann <ah519 at cam.ac.uk> wrote:
> >> Hello,
> >>
> >> I am new to VisIt and have been searching for quite a bit where you can
> >> specify, if at all, a default value for a NaN or dataset fill value.
> >>
> >> I am generating netCDF datasets with -9.9e+32 as default NaN, and
> >> obviously this does not make my data very displayable.
> >>
> >> Any suggestions?  Many thanks in advance for your help,
> >>
> >> Best wishes,
> >>
> >> Lex
> >>
> >> --
> >> ______________________________________________________________________
> >>
> >> Alex HOFFMANN                     PhD Student
> >> Centre for Atmospheric Science
> >> Department of Geography           University of Cambridge
> >> Downing Place, Cambridge CB2 3EN, UK
> >> ______________________________________________________________________
> >> --
> >> List subscription information:
> https://email.ornl.gov/mailman/listinfo/visit-users
> >> Searchable list archives: https://email.ornl.gov/pipermail/visit-users
> >> VisIt Users Wiki: http://visitusers.org/
> >> Frequently Asked Questions for VisIt: http://visit.llnl.gov/FAQ.html
> >>
> >>
> > --
> > List subscription information:
> https://email.ornl.gov/mailman/listinfo/visit-users
> > Searchable list archives: https://email.ornl.gov/pipermail/visit-users
> > VisIt Users Wiki: http://visitusers.org/
> > Frequently Asked Questions for VisIt: http://visit.llnl.gov/FAQ.html
> >
> --
> List subscription information:
> https://email.ornl.gov/mailman/listinfo/visit-users
> Searchable list archives: https://email.ornl.gov/pipermail/visit-users
> VisIt Users Wiki: http://visitusers.org/
> Frequently Asked Questions for VisIt: http://visit.llnl.gov/FAQ.html
>
>


-- 
Ashutosh Singh

PhD student
Hydrogeology
Center of Applied Geosciences
Sigwartstr.10
72076 Tübingen
phone: +49-(0)7071-2973174
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://email.ornl.gov/pipermail/visit-users/attachments/20100325/b7c08970/attachment.html>


More information about the visit-users mailing list