Re: Shade land in oceanic plot

From: Adam Phillips <asphilli_at_nyahnyahspammersnyahnyah>
Date: Thu, 16 Apr 2009 14:38:28 -0600

Hi Vinit,
Assuming that you have the bathymetry information, it isn't that bad.
You will want to form a 1D array of your bathymetry information over
whatever longitude your cross section is at. After that, you need to
fill in arrays with the polygon coordinates. The idea is that you are
drawing a line around the box that you want to fill. So, as a very
simple example where your latitudes = -90,-45,0,45,90 and the depths for
those latitudes = 0,500,1520,2000,800:
xcoord = (/90, -90,-90, -45, 0, 45, 90, 90/) ; latitude
ycoord = (/5000,5000, 0, 500,1520,2000,800,5000/) ; depth
; 5000=arbitrary max depth

then you pass in those coordinates to gsn_add_polygon

Note: This method may not be the most visually appealing method, in that
the depth will be drawn from latitude point to latitude point, but I
don't think you have any other option.
Good luck,
Adam

Asher, Vinit Narendra wrote:
> Hi Adam,
>
> The cnMissingValFillColor = "black" didn't work. Could you give me a brief description on how to use the gsn_add_polygon function?
>
> Best Regards,
>
> Vinit Asher
> vinit.asher_at_mavs.uta.edu
>
>
> In reply to
>
> From: Adam Phillips <asphilli_at_nyahnyahspammersnyahnyah>
> Date: Mon, 13 Apr 2009 11:03:11 -0600
> Hi Vinit,
> Have you tried setting: cnMissingValFillColor = "black" ? (My original
> suggestion of setting this resource = "transparent" and mpLandFillColor
> = "black" was based on the thought that you were constructing a lat x
> lon map.)
> If that doesn't work then you can try using the bathymetry information
> (assuming you have it). You can use gsn_add_polygon to outline the ocean
> floor and then fill in beneath it. Adam
> Asher, Vinit Narendra wrote:
>> Hey Adam
>>
>> I am plotting an lat vs sea-depth plot averaged over the longitudes
>>
>> You are right, it does give _FillValue : 9.97e+36 on printVarSummary
>>
>> But the 2 choices don't work. The plot remains the same.
>>
>> Best Regards,
>>
>> Vinit Asher
>> Email: vinit.asher_at_mavs.uta.edu
>> Cell: 817-201-2396
>>
>> ________________________________________
>> From: asphilli_at_ucar.edu [asphilli_at_ucar.edu]
>> Sent: Friday, April 10, 2009 2:17 PM
>> To: Asher, Vinit Narendra
>> Subject: RE: [ncl-talk] Shade land in oceanic plot
>>
>> Hi Vinit,
>> I'm always happy to help, but it's usually best to respond to the ncl-talk
>> group, as someone might have a better idea than I do! That being said, are
>> you drawing a cross section (say lat x depth), or plotting ocean
>> temperature on a map?
>>
>> As far as the land/_FillValue question: When you do a printVarSummary,
>> does it say your _FillValue : 9.97e+36 ? I bet it does.
>> Adam
>>
>>
>>> Hi Adam,
>>>
>>> Thanks for the information. How do I check if land = _FillValue in my data
>>> or not?
>>>
>>> I tried both ways. My plot remains unchanged. :(
>>>
>>> Best Regards,
>>>
>>> Vinit Asher
>>> vinit.asher_at_mavs.uta.edu
>>> ________________________________________
>>> From: Adam Phillips [asphilli_at_cgd.ucar.edu]
>>> Sent: Friday, April 10, 2009 12:34 PM
>>> To: Asher, Vinit Narendra
>>> Cc: ncl-talk_at_ucar.edu
>>> Subject: Re: Shade land in oceanic plot
>>>
>>> Hi Vinit,
>>> If the data over land = _FillValue, as I am guessing yours is, then all
>>> areas set to _FillValue are color filled with the background color, in
>>> most cases white.
>>>
>>> You have two choices that I can think of:
>>> 1) If the resource applies, and you are not setting cnFillMode =
>>> "RasterFill", then you can set cnMissingValFillColor = "transparent".
>>> http://www.ncl.ucar.edu/Document/Graphics/Resources/cn.shtml#cnMissingValFillColor
>>> Make sure mpLandFillColor = "black"
>>>
>>> 2) Again, set mpLandFillColor = "black", and then set mpFillDrawOrder =
>>> "PostDraw", which will fill the land last, covering up whatever data
>>> color fill was present over land.
>>>
>>> Others might have other suggestions..
>>> Good luck,
>>> Adam
>>>
>>> Asher, Vinit Narendra wrote:
>>>> Hello,
>>>>
>>>> I have a oceanic data file where I am trying to plot the ocean
>>>> TEMPERATURE field
>>>>
>>>> The value of the field for regions where there is land is 9.97e+36
>>>>
>>>> However the displayed range of values for the variable (in ncview) shows
>>>> -1.46 to 34
>>>>
>>>> Could you help me figure out how to color the land black in the plot
>>>>
>>>> Best Regards,
>>>>
>>>> Vinit Asher
>>>> vinit.asher_at_mavs.uta.edu
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>> --
>>> --------------------------------------------------------------
>>> Adam Phillips asphilli_at_ucar.edu
>>> National Center for Atmospheric Research tel: (303) 497-1726
>>> ESSL/CGD/CAS fax: (303) 497-1333
>>> P.O. Box 3000
>>> Boulder, CO 80307-3000 http://www.cgd.ucar.edu/cas/asphilli
>>>
>> _______________________________________________
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> --
> --------------------------------------------------------------
> Adam Phillips asphilli_at_ucar.edu
> National Center for Atmospheric Research tel: (303) 497-1726
> ESSL/CGD/CAS fax: (303) 497-1333
> P.O. Box 3000
> Boulder, CO 80307-3000 http://www.cgd.ucar.edu/cas/asphilli
> _______________________________________________
> ncl-talk mailing list
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-- 
--------------------------------------------------------------
Adam Phillips			             asphilli_at_ucar.edu
National Center for Atmospheric Research   tel: (303) 497-1726
ESSL/CGD/CAS                               fax: (303) 497-1333
P.O. Box 3000				
Boulder, CO 80307-3000	  http://www.cgd.ucar.edu/cas/asphilli
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Received on Thu Apr 16 2009 - 14:38:28 MDT

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