[ncl-talk] overlay

Mary Haley haley at ucar.edu
Fri Nov 16 10:32:43 MST 2018


Sorry, I forgot to mention that if you want to get contour lines for RH2,
but you also want to fill in particular areas, then you need to use
gsn_contour_shade.  The script and image I just sent you has an example of
this.

For information and examples on gsn_contour_shade, see coneff_13.ncl at:

http://www.ncl.ucar.edu/Applications/coneff.shtml#ex13

--Mary


On Fri, Nov 16, 2018 at 10:29 AM Mary Haley <haley at ucar.edu> wrote:

> Ehsan,
>
> Part of the problem may be that wrf_map_resources sets a bunch of
> resources that sets your map outlines to gray, and makes them half as
> thick, making them hard to see.
>
> I've modified the same script I sent you before, but changed some
> resources to make the map outlines really thick and white, so you could see
> them better. I commented out the shapefile outlines.
>
> If you continue to have problems, I will need to see your script.
>
> For more information about map outlines, go to
>
> http://www.ncl.ucar.edu/Applications/mapoutlines.shtml
>
> and look at mapoutlines_7.ncl.  It shows how to get different levels of
> map outlines in your map.
>
> I suggest looking at the WRF/GSN examples page more closely, as it has
> examples on how to customize the map outlines. In particular, look at
> example wrf_gsn_6.ncl:
>
> http://www.ncl.ucar.edu/Applications/wrfgsn.shtml
>
> --Mary
>
>
>
> On Fri, Nov 16, 2018 at 5:25 AM Ehsan Taghizadeh <
> ehsantaghizadeh at yahoo.com> wrote:
>
>> Dear Mary
>>
>> I've changed a little your script, as I just want "2m RH" and "10 u,v".
>> I've also added my shape files. However I had my two main problems, yet.
>> 1- I couldn't have countries boundaries, in spite of adding following
>> lines:
>>
>> rh_res = wrf_map_resources(f,rh_res)    ; Required for setting native WRF
>> map projection
>> (instead of: tc_res = wrf_map_resources(f,tc_res))
>>
>> ;---Boundaries (3 following lines Don't work???)
>>  rh_res at mpDataSetName            = "Earth..4"   ; 1 through 4
>>  rh_res at mpNationalLineColor      = "black" ; "mpCountyLineColor" doesn't
>> work
>>  rh_res at mpNationalLineThicknessF = 2.5     ; "mpCountyLineThicknessF"
>> doesn't work
>>
>>
>> 2- I want to draw "RH" contours for all values, and fill it just for
>> RH>=80%.
>>
>> Attached file is output of edited script.
>>
>>
>>
>> Sincerely
>> Ehsan
>>
>> On Thursday, November 15, 2018, 9:23:21 PM GMT+3:30, Mary Haley <
>> haley at ucar.edu> wrote:
>>
>>
>> Ehsan,
>>
>> Please include ncl-talk when you have followup questions about ncl-talk,
>> unless we specifically ask to take the conversation offline.
>>
>> [1] If you are attaching shapefile outlines, in general you don't also
>> want to be drawing NCL's map outlines.  So, you shouldn't need to set
>> mpOutlineBoundarySets or mpDataSetName.
>>
>> If you do need to set these for some reason, then you need to set these
>> resources for when you call one of the gsn map functions, like gsn_csm_map
>> or gsn_csm_contour_map.
>>
>> [2] To just fill in the RH2 values above 80, you can give gsn_csm_contour
>> one contour level and then provide two colors to indicate what color you
>> want for everything less than that level, and what color you want for
>> everything greater than or equal to it.
>>
>> Something like this:
>>
>>  rh_res at cnFillOn             = True
>>  rh_res at cnLevelSelectionMode = "ExplicitLevels"
>>  rh_res at cnLevels             = 80.
>>  rh_res at cnFillColors         = (/"transparent","navyblue"/)
>>  rh_res at cnLineLabelsOn       = False
>>  rh_res at lbLabelBarOn         = False
>>
>> Note that this will fill in everything where RH2 >= to 80 (not RH 2 >
>> 80).  If you really need to do this for RH2 > 80, then you can use a
>> slightly bigger value for the contour level.
>>
>> Another way to do this is to use the "where" function:
>>
>> rh2 at _FillValue = -999
>> rh2 = where(rh2.gt.80,rh2,rh2 at _FillValue)
>>
>> When you do this, however, you may notice that the RH2 contours are now
>> blocky looking, because NCL can't give you smooth contours at locations
>> that go up against a bunch of missing values. Also you will now get a
>> warning:
>>
>> warning:ContourPlotSetValues: Data values out of range of levels set by
>> EXPLICITLEVELS mode
>>
>> because NCL is not finding any values below 80, and it's just warning you
>> about this.
>>
>> I've attached a sample script that shows RH2 (filled in navy blue) and
>> the difference between using "where" and not.
>>
>> --Mary
>>
>>
>>
>>
>>
>>
>>
>>
>> On Wed, Nov 14, 2018 at 11:11 PM, Ehsan Taghizadeh <
>> ehsantaghizadeh at yahoo.com> wrote:
>>
>> Dear Mary
>> Thank you very much for your helpful reply. I used "wrf_gsn_5.ncl" from
>> https://www.ncl.ucar.edu/ Applications/wrfgsn.shtml
>> <https://www.ncl.ucar.edu/Applications/wrfgsn.shtml>
>> and added shapefiles to "map".
>> I need two more helps now, and I'll be thankful if I could have any
>> suggestion again:
>>
>> 1- where should I add boundaries
>> @mpOutlineBoundarySets = "National"
>> @mpDataSetName            = "Earth..4"   ; 1 through 4
>>
>> I've tried to add them to "res_map", but it seems doesn't work!
>>
>> 2- I've used "2m Relative Humidity" and contoured it. How could I fill it
>> just for RH>80% (just one color)
>>
>> If it helps I could attach the script. However I've attached one sample
>> of output.
>>
>> Sincerely
>> Ehsan
>> On Wednesday, November 14, 2018, 8:51:23 PM GMT+3:30, Mary Haley <
>> haley at ucar.edu> wrote:
>>
>>
>> Ehsan,
>>
>> Please see example wrf_gsn_5.ncl and wrf_nogsn_5.ncl at
>>
>> https://www.ncl.ucar.edu/ Applications/wrfgsn.shtml
>> <https://www.ncl.ucar.edu/Applications/wrfgsn.shtml>
>>
>> It shows you how to overlay several WRF plots on top of each other, using
>> WRF plotting functions, and gsn_csm plotting functions.
>>
>> Adding shapefile outlines should be done to the map plot, and I believe
>> there's an example on the same page.
>>
>> --Mary
>>
>>
>> On Wed, Nov 14, 2018 at 12:49 AM, Ehsan Taghizadeh <
>> ehsantaghizadeh at yahoo.com> wrote:
>>
>> Hi,
>> I have some basic problems about overlaying different quantities of WRF,
>> for a few months and unfortunately, until now I couldn't solve it and I'll
>> be thankful if I could have any help for this.
>> I saw "https://www.ncl.ucar.edu/ Training/Tutorials/WRF_Users_
>> Workshop/WRF_NCL.shtml
>> <https://www.ncl.ucar.edu/Training/Tutorials/WRF_Users_Workshop/WRF_NCL.shtml>",
>> (wrf_demo_plot_tc_gsn_ shapefiles.ncl
>> <https://www.ncl.ucar.edu/Training/Tutorials/WRF_Users_Workshop/Scripts/wrf_demo_plot_tc_gsn_shapefiles.ncl>).
>> It is near to what if want. I just want to add some quantities to it and
>> overlay on it"
>> uv10 = wrf_user_getvar(f0,"uvmet10", it);  u at 10 m, mass point
>> rh2 = wrf_user_getvar(f,"rh2",0);        2m Relative Humidity (%)
>>
>> I mean overlay of "uv10" as vector and "rh2" as contour, on "terrain" and
>> "shapefiles".
>> I've written some scripts and I could send it. I want to use
>> "gsn_csm_countour", "gsn_csm_vector", and "overlay" for related quantities.
>> I hear from Mary Haley "I recommend that people use the
>> gsn_csm_contour_map function for plotting WRF data when they need to add a
>> lot of customization to the plot", for that reason I pointed "gsn".
>>
>> I'll be thankful for any help. As I said above I have this problem for a
>> few months, before August, when I tried to plot a cross-section of WRF
>> quantities with overlaying them. For now, I just want vector and contour,
>> not a cross-section.
>>
>> Sincerely
>> Ehsan
>>
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