[ncl-talk] Disappearing Dots (Revisited)

Tue Jan 14 12:05:59 MST 2020

Hi Barry,
If I had to guess, it is that the arrow function writes the
gsn_add_polyline output as attributes named arr,arr1, and arr2 to the plt
array that is to be returned by the function. If you call the function
multiple times and pass all the graphical output to the same logical array
named "array", each time you call arrow, array at arr, array at arr1 and
array at arr2 will get overwritten.  To get around this, you should alter the
arrow function to use the unique_string function.
https://www.ncl.ucar.edu/Document/Functions/Built-in/unique_string.shtml

For an example of how to do this, see polymarker example #18:
https://www.ncl.ucar.edu/Applications/polyg.shtml#ex18

For example, change this:
plt at arr = gsn_add_polyline(wks,plt,xpts,ypts,res)
to this:
str = unique_string("arr")
plt@$str$ = gsn_add_polyline(wks,plt,xpts,ypts,res)

and do the same for the other two calls to gsn_add_polyline.
Hope that helps!
Adam

On Tue, Jan 14, 2020 at 9:45 AM Barry Lynn via ncl-talk <ncl-talk at ucar.edu>
wrote:

> Hi:
>
> I have a bit of a mystery:
>
> I have a loop where I am calling gsn_add_polymarker. I created an array
> (dum_b(n_calls)) so I could plot the markers within the loop.
>
> dum_b(i) = gsn_add_polymarker(wks,plot,lon_old(i),lat_old(i),mkres)
>
>
> However, when I call:
>
>
> array(i) = arrow(wks,plot,xpts,ypts,mkres)
>
>
> I am not able to make the lines with the arrows (more than once).
>
>
> warning:TransformPostDraw: tfPolyDrawList element 1 is invalid
>
>
> Yet, if I call the same with
>
>
> arr_0 = arrow...
>
>
> arr_1 = arrow...
>
>
> up to n_calls, I have no problem.
>
>
> If someone can solve the mystery, I would be curious to find out the
> reason for this "strange" behavior.
>
>
> https://www.ncl.ucar.edu/Support/talk_archives/2010/att-1344/arrow.ncl
>
> On Mon, Jul 8, 2019 at 12:13 PM Barry Lynn <barry.h.lynn at gmail.com> wrote:
>
>> Hi:
>>
>> That was absolutely the correct solution -- thank you.
>>
>> Are you aware of a way to increase the spacing between maps?  I am using
>> wrf resources so this is very obtuse.
>>
>> Barry
>>
>> On Mon, Jul 8, 2019 at 10:44 AM Rashed Mahmood <rashidcomsis at gmail.com>
>> wrote:
>>
>>> Hi Barry,
>>> A quick look suggests that it may be related to not specifying unique
>>> ids for markid and textid:
>>>     markid = gsn_add_polymarker(wks,plots(0),lon,lat,mkres)
>>>     textid = gsn_add_text(wks,plots(0),cities,lon,lat,txres)
>>>
>>> Next lines should have,
>>> markid*1 *= gsn_add_polymarker(wks,plots(0),lon,lat,mkres)
>>> textid*1* = gsn_add_text(wks,plots(0),cities,lon,lat,txres)
>>>
>>> and so on...
>>>
>>> Cheers
>>>
>>> Rashed
>>>
>>>
>>> On Mon, Jul 8, 2019 at 7:51 AM Barry Lynn via ncl-talk <
>>> ncl-talk at ucar.edu> wrote:
>>>
>>>> Hello:
>>>>
>>>> For some reason, the markid only appears on the last graph, but not the
>>>> first two.  Yet, the "call" to each is the same.  I had this problem in
>>>> other programs I wrote.
>>>>
>>>> If you have a suggestion, thank you,
>>>>
>>>> Barry
>>>> --
>>>> Barry H. Lynn, Ph.D
>>>> Senior Associate Scientist, Lecturer,
>>>> The Institute of the Earth Science,
>>>> The Hebrew University of Jerusalem,
>>>> Givat Ram, Jerusalem 91904, Israel
>>>> Tel: 972 547 231 170
>>>> Fax: (972)-25662581
>>>>
>>>> C.E.O, Weather It Is, LTD
>>>> Weather and Climate Focus
>>>> http://weather-it-is.com
>>>> Jerusalem, Israel
>>>> Local: 02 930 9525
>>>> Cell: 054 7 231 170
>>>> Int-IS: x972 2 930 9525
>>>>
>>>> _______________________________________________
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>>>
>>>
>>
>> --
>> Barry H. Lynn, Ph.D
>> Senior Associate Scientist, Lecturer,
>> The Institute of the Earth Science,
>> The Hebrew University of Jerusalem,
>> Givat Ram, Jerusalem 91904, Israel
>> Tel: 972 547 231 170
>> Fax: (972)-25662581
>>
>> C.E.O, Weather It Is, LTD
>> Weather and Climate Focus
>> http://weather-it-is.com
>> Jerusalem, Israel
>> Local: 02 930 9525
>> Cell: 054 7 231 170
>> Int-IS: x972 2 930 9525
>>
>>
>
> --
> Barry H. Lynn, Ph.D
> Senior Associate Scientist, Lecturer,
> The Institute of the Earth Science,
> The Hebrew University of Jerusalem,
> Givat Ram, Jerusalem 91904, Israel
> Tel: 972 547 231 170
> Fax: (972)-25662581
>
> C.E.O, Weather It Is, LTD
> Weather and Climate Focus
> http://weather-it-is.com
> Jerusalem, Israel
> Local: 02 930 9525
> Cell: 054 7 231 170
> Int-IS: x972 2 930 9525
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

-- 
Adam Phillips
Associate Scientist,  Climate and Global Dynamics Laboratory, NCAR
www.cgd.ucar.edu/staff/asphilli/   303-497-1726

<http://www.cgd.ucar.edu/staff/asphilli>
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