[ncl-talk] Fwd: Pennants wind barbs thickness

Rabah Hachelaf hachelaf at sca.uqam.ca
Thu Jul 24 16:11:54 MDT 2014 

Thanks for you David and Kyle.


2014-07-24 18:08 GMT-04:00 David Brown <dbrown at ucar.edu>:

> 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
>>>>>>>      ____
>>>>>>>     (       )
>>>>>>>    (        )
>>>>>>>   (___ __)
>>>>>>>    /////////
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> ncl-talk mailing list
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>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> ------------------------------
>>>>> Cordialement,
>>>>> Best regards,
>>>>> Rabah Hachelaf
>>>>>
>>>>> _______________________________________________
>>>>> ncl-talk mailing list
>>>>> List instructions, subscriber options, unsubscribe:
>>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> ------------------------------
>>> Cordialement,
>>> Best regards,
>>> Rabah Hachelaf
>>>
>>
>>
>


-- 
------------------------------
Cordialement,
Best regards,
Rabah Hachelaf
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