[ncl-talk] (no subject)

[Mary Haley]

Wiston,

If I understand your code correctly, then I think you need to use the
special "ZoomIn" attribute that tells the NCL-WRF plotting scripts how to
zoom in on a WRF plot.

It looks like you got the index locations of the lat/lon area of interest,
but then you didn't do anything with this information:

       loc  =
wrf_user_ll_to_ij(a,(/Min_Lon,Max_Lon/),(/Min_Lat,Max_Lat/),opts)

Once you get "loc", you can use this with the "ZoomIn" feature to tell the
wrf_map_overlays procedure how to zoom in, via this code:

       ; loc(0,:) is west-east (x) ; loc(1,:) is south-north (y)

       ; subtract one since we want to use it as an index in NCL

         mpres at ZoomIn = True        ; set up map info for zoomed area

         mpres at Xstart = loc(0,0) - 1
         mpres at Xend   = loc(0,1) - 1
         mpres at Ystart = loc(1,0) - 1
         mpres at Yend   = loc(1,1) - 1


You will also want to comment or remove this code:

              ;;; Setting plotting options

;              mpres at mpMaxLatF  = Max_Lat

;              mpres at mpMinLatF  = Min_Lat

;           mpres at mpMinLonF  = Min_Lon

;              mpres at mpMaxLonF  = Max_Lon

To see a full example of using ZoomIn, go to:

http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Graphics/NCL/Examples/SPECIAL/olr.htm

and look at the "olr.ncl" script.

--Mary


On Wed, Feb 11, 2015 at 11:44 AM, Modise Wiston <
modise.wiston at postgrad.manchester.ac.uk> wrote:

>  Hi,
>
> I want plot data from a larger domain to compare the output [low
> resolution] with results from a smaller grid [high resolution] for the same
> location..
> The larger domain is the parent to the smaller domain (ratio 20:4). I want
> to extract data from the large grid just for the grid cells where the
> smaller domain is located and plot data to compare the results as if I am
> have results from the same grid at two different resolutions.
>
> I defined the coordinates for the smaller domain (on the parent grid) and
> I am able to have the map background around the small grid only. However,
> my script plots data from across the whole parent grid *Not just for the
> grid cells defined* in the coordinates..
>
> Any help on how I can do this please.. I want the plotted data for the
> small grid ONLY?
> (See attached code in the script please)
>
>
> Thank you,
> Wiston
>
> _______________________________________________
> ncl-talk mailing list
> 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/20150213/01fae6eb/attachment.html