[ncl-talk] Strange stippling behaviour when valid points are few and scattered apart

[Rashed Mahmood]

I do not think that we should use 0 as missing value, please also see this
page:
http://www.ncl.ucar.edu/Document/Language/error_messages.shtml#ZeroMissingValue
and no, setting _FillValue to some arbitrary number does not work.

I am guessing that there may be a workaround for this, which I haven't
found yet!



On Wed, Jul 1, 2020 at 7:06 PM Buzan, Jonathan <jbuzan at purdue.edu> wrote:

> I think it’s interpolating between the data.
> Have you tried deleting the _FillValue and set it to 0 (or some arbitrary
> number)?
>
> -Jonathan
>
>
>
>
>
> On Jul 1, 2020, at 6:25 PM, Rashed Mahmood <rashidcomsis at gmail.com> wrote:
>
> Jonathan,
> Please look at the if statement that was introduced just to play with it a
> bit. Please have a look at the plot named *_Original.pdf. This is what the
> question is about.
>
> Rashed
>
> On Wed, Jul 1, 2020 at 6:03 PM Buzan, Jonathan <jbuzan at purdue.edu> wrote:
>
>> Hi Rashed,
>>
>> Looking at your script, it looks like the stipple is doing exactly what
>> you said it to do:
>>
>>       do n=0,20
>>          sig({n},:) = 95.01
>>       end do
>>
>>
>> You set  resS at cnLevels             =(/ 95.,100. /)
>>
>> The {n} in sig({n},:) means to set the latitudes 0-20 to 95.01. And the
>> stipple is greater than 95. But lower than 100. So it stippled from 0-20
>> latitude.
>>
>> -Jonathan
>>
>>
>>
>>
>> > On Jul 1, 2020, at 5:57 PM, Rashed Mahmood via ncl-talk <
>> ncl-talk at mailman.ucar.edu> wrote:
>> >
>> > Hi NCL,
>> >
>> > I encountered strange stippling behaviour when valid data points are
>> very few and are scattered apart from each other. At best I would expect no
>> stippling overlaid on a filled map, however, it seems that NCL somehow
>> covers the whole map with stippling.
>> >
>> > To explain this, I created a small example script (attached) which
>> reads data from the attached file. To play with it a bit, I just added some
>> "fake data" to see what happens. In the script we could set it using
>> "add_bogus_data = True".
>> > Attached are two plots after using original data and adding some fake
>> data. I am not sure what is going on here, anyone? Ignore the file names!!
>> >
>> > Cheers
>> > Rashed
>> >
>> > <funny_stiple.ncl><tst_diff.nc
>> ><Mask_TEST_Original.pdf><Mask_TEST_Bogus.pdf>_______________________________________________
>> > ncl-talk mailing list
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>>
>>
>
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