[ncl-talk] Strange issue on plotting

Fri Oct 1 15:55:43 MDT 2021

Hi Andrew,
I think you have happened upon a rare NCL graphics bug. I have seen this
issue when all the data falls within one contour interval (say 2-3 in your
case), but it is quite rare. That is not the case here, as your "Automatic
Levels" plots show values in the regional plot varying between 2.5 and 30.
I too am puzzled by the absence of any error messages when the failed
all-green plot is drawn.

Are you setting cnFIllMode = "RasterFill"? I thought you were, but now I am
not so sure. If not I would say try it (with ExplicitLevels). Other things
to try are setting your contour levels (very slightly) differently, for
example setting the bottom contour = 0.1000001 (but you can still label it
as 0.1).

Beyond that, I unfortunately do not know what to suggest. Perhaps another
user has encountered this issue before and can offer a solution.
Adam

On Fri, Oct 1, 2021 at 1:56 PM Andrew Kren - NOAA Federal <
andrew.kren at noaa.gov> wrote:

> All,
> As you suspected, switching to AutomaticLevels fixed the issue. I am
> sharing the plots of zoomed in map/regional map for AutomaticLevels and my
> ExplicitLevels. I see that the values are out of range, but confused why it
> didn't error out on the regional map? Does this mean I can't set my own
> levels?
>
> Thanks,
>
> On Wed, Sep 29, 2021 at 3:31 PM Adam Phillips <asphilli at ucar.edu> wrote:
>
>> Joseph: Thanks for jumping in! I was wondering if it was the same issue
>> you identified. Andrew: Please let us know the results..
>> Adam
>>
>> On Wed, Sep 29, 2021 at 1:18 PM Andrew Kren - NOAA Federal <
>> andrew.kren at noaa.gov> wrote:
>>
>>> I'll try that.
>>>
>>> On Wed, Sep 29, 2021 at 2:09 PM Joseph Clark <jpclark186000 at gmail.com>
>>> wrote:
>>>
>>>> Sorry for jumping in here. Perhaps set resources at cnLevelSelectionMode
>>>> = "AutomaticLevels". My guess is your data is out of the range on your
>>>> color bar on these days. I think the automatically generated color bar will
>>>> tell you what the range of your data values are.
>>>>
>>>> On Wed, Sep 29, 2021, 1:58 PM Andrew Kren - NOAA Federal via ncl-talk <
>>>> ncl-talk at mailman.ucar.edu> wrote:
>>>>
>>>>> Hi Adam,
>>>>> Thanks for the quick reply. There are no error messages when it plots
>>>>> the two regions. I would say no to your second question. For example, for
>>>>> the same hour, the regional map shows a totally different picture but the
>>>>> zoomed in version is all one color. I am using the same HRRR grid to plot
>>>>> both regions. Could it be that I need to use a different fill type (raster
>>>>> vs another) since the data can be sort of non-uniform and NCL is trying to
>>>>> smoothly contour it?
>>>>>
>>>>> On Wed, Sep 29, 2021 at 1:11 PM Adam Phillips <asphilli at ucar.edu>
>>>>> wrote:
>>>>>
>>>>>> Hi Andrew,
>>>>>> 2 questions:
>>>>>> 1 - Are any error messages returned when the plot with the red fill
>>>>>> occurs?
>>>>>> 2 - Is there a chance that the HRRR data for that particular metric
>>>>>> and region all fits into one contour interval (as for example all the data
>>>>>> has values say greater than 50kft, or all data falls between 5-10kft)?
>>>>>> Adam
>>>>>>
>>>>>> On Wed, Sep 29, 2021 at 2:48 AM Andrew Kren - NOAA Federal via
>>>>>> ncl-talk <ncl-talk at mailman.ucar.edu> wrote:
>>>>>>
>>>>>>> Hi there,
>>>>>>>
>>>>>>> I'm wondering if anyone has ever run into this issue when plotting.
>>>>>>> I am contouring HRRR cloud ceiling data on a regional and local domain of
>>>>>>> NC. For certain hours, there is one color on top of the map, such that it
>>>>>>> appears the contouring didn't work correctly. This is only found on the
>>>>>>> smaller domain and not the regional domain for the same time periods. I
>>>>>>> thought maybe this was related to me using a triangular mesh, but that
>>>>>>> wouldn't fully make sense. I am attaching the images.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>> Andrew Kren
>>>>>>> Meteorologist
>>>>>>> NOAA's National Weather Service
>>>>>>> Raleigh Forecast Office
>>>>>>> 1005 Capability Drive, Suite 300
>>>>>>> Raleigh, North Carolina 27606
>>>>>>> voice: 919-326-1035
>>>>>>> mailto: andrew.kren at noaa.govhttp://www.weather.gov/rah
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ncl-talk mailing list
>>>>>>> ncl-talk at mailman.ucar.edu
>>>>>>> List instructions, subscriber options, unsubscribe:
>>>>>>> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Adam Phillips
>>>>>> Associate Scientist,  Climate and Global Dynamics Laboratory, NCAR
>>>>>> www.cgd.ucar.edu/staff/asphilli/   303-497-1726
>>>>>>
>>>>>> <http://www.cgd.ucar.edu/staff/asphilli>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> Andrew Kren
>>>>> Meteorologist
>>>>> NOAA's National Weather Service
>>>>> Raleigh Forecast Office
>>>>> 1005 Capability Drive, Suite 300
>>>>> Raleigh, North Carolina 27606
>>>>> voice: 919-326-1035
>>>>> mailto: andrew.kren at noaa.govhttp://www.weather.gov/rah
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> ncl-talk mailing list
>>>>> ncl-talk at mailman.ucar.edu
>>>>> List instructions, subscriber options, unsubscribe:
>>>>> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>>> --
>>>
>>> Andrew Kren
>>> Meteorologist
>>> NOAA's National Weather Service
>>> Raleigh Forecast Office
>>> 1005 Capability Drive, Suite 300
>>> Raleigh, North Carolina 27606
>>> voice: 919-326-1035
>>> mailto: andrew.kren at noaa.govhttp://www.weather.gov/rah
>>>
>>>
>>>
>>
>> --
>> Adam Phillips
>> Associate Scientist,  Climate and Global Dynamics Laboratory, NCAR
>> www.cgd.ucar.edu/staff/asphilli/   303-497-1726
>>
>> <http://www.cgd.ucar.edu/staff/asphilli>
>>
>
>
> --
>
> Andrew Kren
> Meteorologist
> NOAA's National Weather Service
> Raleigh Forecast Office
> 1005 Capability Drive, Suite 300
> Raleigh, North Carolina 27606
> voice: 919-326-1035
> mailto: andrew.kren at noaa.govhttp://www.weather.gov/rah
>
>
>

-- 
Adam Phillips
Associate Scientist,  Climate and Global Dynamics Laboratory, NCAR
www.cgd.ucar.edu/staff/asphilli/   303-497-1726

<http://www.cgd.ucar.edu/staff/asphilli>
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