<div dir="ltr"><div dir="ltr"><div>Hi all,</div>My reply was accidentally not attached in the previous reply, so I have added it here.<div>----------------------</div><div>Hi all,<div>Building upon what Rick said (offline), this is obviously a graphics bug of some kind. I believe this bug exists in other similar situations as well. I think what is going on is that the valid values all fall between 95 and 100 (which are the set contour levels), and the rest of the values are set to _FillValue. This leads to a situation where all valid values fall between two contours, which is a situation that NCL admittingly does not handle well when filling, and can lead </div><div><br></div><div>Another thing to keep in mind is that when stippling, <i>NCL</i> <i>does not apply stipple at each grid box</i>. If a minimal number of points are spaced apart from one another, stippling might not be shown at all. Setting cnFIllMode = "RasterFIll" does not alter this behavior at all. This is the downside of using stippling on sparse spatially inhomogeneous data. The solution to this issue is to not use any of the gsn_csm_* plotting routines, but to use gsn_add_polymarker to add a dot (or stipple) at each significant grid box. </div><div><br></div><div>I have attached a script that will color fill the significant grid boxes green (done only to highlight where the boxes are), and then will apply a polymarker to each valid grid box.</div><div><br></div><div>Hope that helps!</div><div>Adam</div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Jul 7, 2020 at 6:48 PM Dennis Shea via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>This was looked at offline.</div><div><br></div><div>Likely, there is a "bug of some kind." See Adam's response below. He also provided a sample script</div><div>.</div><div><br></div><div><br></div><div>Adam Phillips provided the attached script.</div><div><br></div><div><div>Stay Healthy</div><div>==========</div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Jul 2, 2020 at 12:57 PM Buzan, Jonathan via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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You need to delete _FillValue and set the number to some arbitrary value.
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<div>-Jonathan</div>
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<div>On Jul 2, 2020, at 8:55 PM, Rashed Mahmood <<a href="mailto:rashidcomsis@gmail.com" target="_blank">rashidcomsis@gmail.com</a>> wrote:</div>
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<div>I do not think that we should use 0 as missing value, please also see this page:</div>
<div><a href="http://www.ncl.ucar.edu/Document/Language/error_messages.shtml#ZeroMissingValue" target="_blank">http://www.ncl.ucar.edu/Document/Language/error_messages.shtml#ZeroMissingValue</a></div>
<div>and no, setting _FillValue to some arbitrary number does not work.</div>
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<div>I am guessing that there may be a workaround for this, which I haven't found yet!</div>
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<div dir="ltr" class="gmail_attr">On Wed, Jul 1, 2020 at 7:06 PM Buzan, Jonathan <<a href="mailto:jbuzan@purdue.edu" target="_blank">jbuzan@purdue.edu</a>> wrote:<br>
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<div>I think it’s interpolating between the data.
<div>Have you tried deleting the _FillValue and set it to 0 (or some arbitrary number)?</div>
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<div>-Jonathan</div>
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<div>On Jul 1, 2020, at 6:25 PM, Rashed Mahmood <<a href="mailto:rashidcomsis@gmail.com" target="_blank">rashidcomsis@gmail.com</a>> wrote:</div>
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<div>Jonathan,</div>
<div>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.</div>
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<div>Rashed<br>
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<div dir="ltr" class="gmail_attr">On Wed, Jul 1, 2020 at 6:03 PM Buzan, Jonathan <<a href="mailto:jbuzan@purdue.edu" target="_blank">jbuzan@purdue.edu</a>> wrote:<br>
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Hi Rashed,<br>
<br>
Looking at your script, it looks like the stipple is doing exactly what you said it to do:<br>
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do n=0,20 <br>
sig({n},:) = 95.01<br>
end do<br>
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You set resS@cnLevels =(/ 95.,100. /)<br>
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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.<br>
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-Jonathan<br>
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> On Jul 1, 2020, at 5:57 PM, Rashed Mahmood via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br>
> <br>
> Hi NCL,<br>
> <br>
> 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.<br>
> <br>
> 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".<br>
> 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!!<br>
> <br>
> Cheers<br>
> Rashed<br>
> <br>
> <funny_stiple.ncl><<a href="http://tst_diff.nc/" rel="noreferrer" target="_blank">tst_diff.nc</a>><Mask_TEST_Original.pdf><Mask_TEST_Bogus.pdf>_______________________________________________<br>
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