[IDV #ZRQ-267528]: Color bar problems

Greetings Jim,

Just an update on your issue with the colorscale - it turns out that the issue 
is in the VisAD library. We are working with SSEC on a possible solution, but 
nothing so far. I suggest using the 'invert colorbar' feature for the time 
being.

I'll let you know as soon as we come up with something.

Cheers!

Sean 

> Hi Jim,
> 
> I see the issue now - thanks for the image. Just as an update, I've found 
> where things appear to be going wrong in the drawing of the colorbar, and I 
> hope to have a fix very soon.
> 
> Thanks for pointing this out!
> 
> Sean
> 
> > Sean:
> >
> > See the attached image, which is of mean annual precipitation over
> > the southwest.  It includes contours and color fil.  The color fill is
> > descending.  Note how, for example, in arizona, the color fill between
> > 10 and 15 inches is red, whereas on the color bar, red is between 5 and 10.
> >
> > Hopefully this will show you what is going on.  The problem arises
> > if you edit the color table and specify a range that is *descending*
> > (e.g., 95-0) rather than *ascending* (e.g., 0-95).  I'm probably the
> > only one in the world to think of doing that, but at the time, I didn't
> > realize you could invert the color table.  perhaps others would try it too.
> >
> > I hope this helps.
> >
> > Jim
> >
> >
> > On 1/27/12 2:07 PM, Unidata IDV Support wrote:
> > > Greetings Jim!
> > >
> > > I've tried to reproduce the situation outlined in you support message, 
> > > but I am just not able to do so.I may have misunderstood, but here is 
> > > what I did.
> > >
> > > 1) I isolated two grid points in a model grid (located next to each 
> > > other). Their values are 955.847 hPa and 962.87 hPa.
> > >
> > > 2) I set the bounds such that each grid point was contained within one 
> > > increment. The upper bound was set to 962.9 hPa and the lower bound was 
> > > set to 955.8 hPa, and the increment was 0.1 hPa
> > >
> > > 3) I changed the color scale and contour information to match the 
> > > increment that contained each point (955.8 - 955.9, 962.8-962.9), and 
> > > made the range such that the two values were on opposite ends of the 
> > > scale. Also, only the first and last increments are set to have color 
> > > (blue and red) - the middle of the range is set to white.
> > >
> > > 4) I switched the range from ascending to descending (from 955.8 ->  
> > > 962.9 to 962.9 ->  955.8). Based on your report, I expected to see one of 
> > > the colored contours to turn to white on the figure, since the contours 
> > > seem to shift one increment on the screen (maybe this is where I am going 
> > > wrong).
> > >
> > >  From what I saw, everything looks ok - both colors still showed up, and 
> > > nothing changed in the contouring shown on the image. I've attached two 
> > > figures showing what I did.
> > >
> > > Perhaps I am misunderstanding the issue? Would you mind sending an 
> > > example (a bundle or some screen shots?).
> > >
> > > Thanks!
> > >
> > > Sean
> > >
> > >>> I recently noticed an issue with the contour color fill legend *in
> > >>> situations where you specify a range that is descending (i.e., from
> > >>> 100-0) rather than ascending (i.e., from 0-100).  If descending, the
> > >>> color fill in the figure is off by one increment compared to the
> > >>> legend.  This is most easily seen if you select a color table with a
> > >>> small number of increments.
> > >>>
> > >>> A work around is to simply invert the color table so that you can use an
> > >>> ascending range, but it would be good to have this fixed so that nobody
> > >>> makes an unanticipated mistake.
> > >>>
> > >>> Thanks,
> > >>>
> > >>> Jim
> > >>>
> > >>>
> > >> Jim,
> > >> It does sound like a bug.
> > >> Thanks for information, we will fix this problem after the AMS.
> > >>
> > >> Yuan
> > >
> > > Ticket Details
> > > ===================
> > > Ticket ID: ZRQ-267528
> > > Department: Support IDV
> > > Priority: Normal
> > > Status: Open
> >
> >
> >
> 


Ticket Details
===================
Ticket ID: ZRQ-267528
Department: Support IDV
Priority: Normal
Status: Open