[ncl-talk] How to remember the overlaid plot inside a function

[Cheung]

           Hi Mary, thanks for your reply.

      I did not use any function like gsn_add_polyxx or gsn_add_text, which can be handled as in the FAQ.

      In my case, I  use the procedure "overlay" to overlay several plots on a base plot,

      as in this function a. The problem is that the "res for plot1" and "res for plot2"

      are forgotten. The warning will persist even if "res for plot1" and "res for plot2"

     are commented. They only disappear when I comment the "overlay" procedure.

 function a
          
                   rex at xxx           = xxx
                   plot                   = gsn_csm_xy(wks,x,y,res)

                   res at xxx           = xxx      ; call this as "res for plot1"
                   plot1                 = gsn_csm_xy(wks,x,y,res)
                   res at xxx           = xxx       ; call this as "res for plot2"
                   plot2                 = gsn_csm_xy(wks,x,y,res)
 
                   overlay(plot,plot1)
                   overlay(plot,plot2)
                   return(plot)

end function a






At 2017-03-07 23:36:31, "Mary Haley" <haley at ucar.edu> wrote:

Cheung,


See:


http://www.ncl.ucar.edu/FAQ/#err_msgs_027



When you get warnings about "tfPolyDrawList", this should have to do with code where you are attaching polylines, polygons, polymarkers, or text to a plot, and not in the creation of the plot itself.


Do you have any code where you are calling gsn_add_polyxxxx or gsn_add_text? If so, then please read the above FAQ question about how to make sure your return values for each call are unique.


--Mary




On Tue, Mar 7, 2017 at 7:44 AM, Cheung <zuibeidemei at 126.com> wrote:

Dear NCL:


                   I use a function to generate certain type of plot.
                   Inside this function, several plots are overlaid on a base plot, like this:


 function a
           
                   rex at xxx           = xxx
                   plot                   = gsn_csm_xy(wks,x,y,res)
                   res at xxx           = xxx      ; call this as "res for plot1"
                   plot1                 = gsn_csm_xy(wks,x,y,res)
                   res at xxx           = xxx       ; call this as "res for plot2"
                   plot2                 = gsn_csm_xy(wks,x,y,res)
                   overlay(plot,plot1)
                   overlay(plot,plot2)
                   return(plot)


end function a


                    Such codes will generate "warning TransformPreDraw: tfPolyDrawList element 0".
                    Although plot1 and plot 2 can be overlaid to the base plot when this function a is called, 
                    the resultant plot lose all "res for plot1, 2". I guess this is because the new "res" are not 
                   "alive" when this plot is returned. Is there any way to solve this?


                    Thanks for your help.


Best
Cheung
      
                 




 


_______________________________________________
ncl-talk mailing list
ncl-talk at ucar.edu
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20170308/9beebcbc/attachment.html