[ncl-talk] Fwd: Pennants wind barbs thickness

Thu Jul 24 16:08:43 MDT 2014

Hi Rabah,

I definitely agree with Kyle's advice. It would be a very time consuming
(and not very rewarding) effort to try to create your own wind barbs using
polylines and polygons. Post-processing the plot with adobe illustrator
would be much easier.
 -dave

On Thu, Jul 24, 2014 at 1:41 PM, Kyle Griffin <ksgriffin2 at wisc.edu> wrote:

> I would suggest making such an effect in a program like Adobe Illustrator
> or similar - it would honestly be an order of magnitude faster to do, or
> even to learn if you are unfamiliar with such software. In reality though,
> it would probably be easier for you to simply choose another color to plot
> in if you are worried about visibility.
>
> The implementation of such a procedure from your end would likely take
> several days to accurately script and be terribly inefficient, as the
> native NCL code is written in a more efficient language. It would also
> still be lacking in many of the basic features that already exist. If you
> really want to get started on such a project, I strongly suggest using the
> NCL documentation as much as possible (including the search) and looking
> over the polygon/polyline example page at
> http://ncl.ucar.edu/Applications/polyg.shtml
> I cannot possibly guide you beyond this as this is not something I would
> recommend anyone try without being very familiar with the intricacies of
> NCL or, preferably, the underlying code. That's why it's wonderful to have
> such responsive developers helping us out and taking requests such as these
> into consideration - even if these requests take a bit of time to fully
> implement.
>
>
> Kyle
>
> ----------------------------------------
> Kyle S. Griffin
> Department of Atmospheric and Oceanic Sciences
> University of Wisconsin - Madison
> Room 1421
> 1225 W Dayton St, Madison, WI 53706
> Email: ksgriffin2 at wisc.edu
>
>
> On Thu, Jul 24, 2014 at 2:29 PM, Rabah Hachelaf <hachelaf at sca.uqam.ca>
> wrote:
>
>> Hi Kyle,
>>
>> My goal is overlay a green windbarb over a black ones with a higher
>> thickness to get a green barb with a black borders like image attached.
>> I success to do that but for winds speed over 50KT the problem about
>> pennant occur.
>>
>> Please can you tell me what is steps to do to create a filled polygone
>> and rotated it to the angle of each wind barb line.
>>
>> Thanks.
>>
>>
>>  2014-07-24 15:13 GMT-04:00 Kyle Griffin <ksgriffin2 at wisc.edu>:
>>
>> As Dave is one of the developers, he does usually know best. However, if
>>> it is very important to you to change it and you have a reasonable number
>>> on your plot, I would recommend outputting your file as a PS, EPS, or PDF
>>> and taking the vector file into a post-processing program such as Adobe
>>> Illustrator or similar. There, you can edit the length/width/color/position
>>> of the lines as necessary. Beyond that, I doubt this feature is simple to
>>> address. If you were going to set about fixing this as a user, you could
>>> start writing the code to draw each line individually relative to a base
>>> point and use the gsn_add_polyline(...) function or similar to try and
>>> construct these on your own. For the pennants, you would likely need
>>> gsn_add_polygon(...) to create a filled polygon, once again rotated to the
>>> angle of each wind barb line. Of course, this would be duplicating much of
>>> the code already written behind-the-scenes in NCL, but it IS possible if
>>> you really need a customized implementation in the immediate future.
>>>
>>>
>>> Kyle
>>>
>>> ----------------------------------------
>>> Kyle S. Griffin
>>> Department of Atmospheric and Oceanic Sciences
>>> University of Wisconsin - Madison
>>> Room 1421
>>> 1225 W Dayton St, Madison, WI 53706
>>> Email: ksgriffin2 at wisc.edu
>>>
>>>
>>> On Thu, Jul 24, 2014 at 1:50 PM, Rabah Hachelaf <hachelaf at sca.uqam.ca>
>>> wrote:
>>>
>>>> Hi David,
>>>>
>>>> Yes i re-post my question maybe some one from NCL users has an other
>>>> idea.
>>>>
>>>> Rabah
>>>>
>>>>
>>>> 2014-07-24 14:11 GMT-04:00 David Brown <dbrown at ucar.edu>:
>>>>
>>>> Hi Rabah,
>>>>> As you know I previously answered this question for you personally
>>>>> prior to your joining ncl-talk. For the record I am now answering on
>>>>> ncl-talk:
>>>>>
>>>>> You have diagnosed the problem correctly, and unfortunately there is
>>>>> no resource to directly control the size of the pennant part of the wind
>>>>> barb glyphs. The size and area of the pennants is fully determined by
>>>>> the vcWindBarbTickLengthF and the vcWindBarbTickAngleF. Unfortunately there
>>>>> is currently no adjustment made to account for the width of the lines,
>>>>> which also has the effect of making the barbs longer than their nominal
>>>>> length. No one has ever asked for this kind of flexibility in the past, but
>>>>> I can see that it could be useful.
>>>>>
>>>>> You could try playing with the tick length and tick angle resources.
>>>>> They may help give you a combination that looks better. But until we can
>>>>> add another option, my suggestion would be to just try to keep the width as
>>>>> small as feasible for your purposes.
>>>>>  -dave
>>>>>
>>>>>
>>>>>
>>>>> On Tue, Jul 22, 2014 at 4:54 PM, Rabah Hachelaf <hachelaf at sca.uqam.ca>
>>>>> wrote:
>>>>>
>>>>>> Hi NCL users,
>>>>>>
>>>>>> I have problem with plotting wind barb with a relatively big
>>>>>> thickness
>>>>>>
>>>>>> I am using vcWindBarbLineThicknessF command to increase wind barb
>>>>>> thickness
>>>>>> it's correct for all wind barbs only for higher than 50KT ones where
>>>>>> the pennants or small triangle aren't affected by the thickness set.
>>>>>> When reading some documentation i noted that
>>>>>>
>>>>>>   " The pennants are drawn using a filled polygon, while the ticks,
>>>>>> the shaft, and the calm circle are all rendered with polylines."
>>>>>>
>>>>>> So i think this is why pennants aren't affected by the thickness
>>>>>> change.
>>>>>>
>>>>>> Have you some tricks to solve this problem and get the same pennants
>>>>>> thickness like the ticks.
>>>>>>
>>>>>> Attached you can find an example of my case, where wind speed is
>>>>>> supposed to be about between 55KT and 60KT
>>>>>>
>>>>>> Thank you.
>>>>>>
>>>>>> ------------------------------
>>>>>> Cordialement,
>>>>>> Best regards,
>>>>>> Rabah Hachelaf
>>>>>> Msc Studient UQAM
>>>>>> Montréal/CANADA
>>>>>>      ____
>>>>>>     (       )
>>>>>>    (        )
>>>>>>   (___ __)
>>>>>>    /////////
>>>>>>
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>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> ------------------------------
>>>> Cordialement,
>>>> Best regards,
>>>> Rabah Hachelaf
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
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>>>>
>>>>
>>>
>>
>>
>> --
>> ------------------------------
>> Cordialement,
>> Best regards,
>> Rabah Hachelaf
>>
>
>
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