[ncl-talk] Zooming Functions Clarification
Illston, Bradley G.
illston at ou.edu
Thu Apr 21 09:52:34 MDT 2016
Mary and Will,
Thank you so much for the help. I am getting closer, but things still seem a bit off after close inspection. My code is below. If I do not zoom (e.g. comment out mpres at ZoomIn = True), I get the following image:
http://res.mesonet.org/~billston/phd/images/ncl-talk/original.png
If I zoom, I get the following image:
http://res.mesonet.org/~billston/phd/images/ncl-talk/zoomed.png
While the “map” does zoom in, the WRF 2m air temperature field does not. You can see this by looking at the contour shapes in the NW corner, for example. I think my code is getting very close, but just missing one final piece. Any ideas? Thank you so much for your assistance.
Cheers,
Brad Illston
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
begin
;---Define colormap. First is background color, second is foreground color
colors = (/(/255, 255, 255/),(/0, 0, 0/),(/255, 255, 255/),(/088, 164, 074/),(/047,124,062/),(/055, 072, 114/),(/095,129,183/),(/094,165,212/),(/116,196,205/),(/135,099,162/),(/128,076,144/)/) / 255.
;---Open WRF output file
a = addfile(wrf_filename,"r")
print(" NetCDF file = "+wrf_filename)
print(" Output image = "+output_png)
global_attnames = getvaratts(a) ;-- retrieve the global attributes from input file
do i=0,dimsizes(global_attnames)-1
print(global_attnames(i) + " = " + a@$global_attnames(i)$) ;-- print global attribute contents
end do
;---Read temperature at first time step
tc = wrf_user_getvar(a,"T2",0)
tc at long_name = "2m Air Temperature"
tc at units = "C"
tc=tc-273.15
wks = gsn_open_wks("png",output_png)
gsn_define_colormap(wks,"WhiteBlueGreenYellowRed") ; choose colormap
; gsn_define_colormap(wks,colors)
;---Resources for filled contour plot
res = True
res at cnFillOn = True
res at cnLinesOn = False
res at gsnMaximize = True
res at tiMainString = run_length + " Run (" + year + ") - " + run_date + " " + end_time + " UTC"
res at Footer = False
res at FieldTitle = "2m Air Temperature"
res at lbTitleOn = True
res at lbTitleString = ""
res at NoHeaderFooter = True ; Switch headers and footers off
res at cnLevelSelectionMode = "ExplicitLevels"
res at cnLevels = (/10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25/)
; res at ContourParameters = (/10,25,1/) ; Contour levels
contour = wrf_contour(a,wks,tc,res) ; Create contour plot
pltres = True ; Basic overlay plot options
pltres at PanelPlot = True ; Tells wrf_map_overlays not to remove overlays
mpres = True ; Set map options
mpres at mpOutlineOn = True ; Turn on map outlines
mpres at mpFillOn = False ; Turn off map fill
mpres at mpDataBaseVersion = "Ncarg4_1"
mpres at mpDataSetName = "Earth..2" ; For counties
mpres at mpOutlineBoundarySets = "GeophysicalAndUSStates"
mpres at mpOutlineSpecifiers = (/"Land", "Oklahoma:counties"/)
mpres at tiMainString = run_length + " Run (" + year + ") - " + run_date + " " + end_time + " UTC"
mpres at gsnMaximize = True
; We are interested in a zoomed area so get the XY points of these points
lats = (/ 35.0, 36.0 /)
lons = (/ -98.2, -96.8 /)
loc = wrf_user_ll_to_ij(a, lons, lats, True)
; 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
x_start = loc(0,0) - 1
x_end = loc(0,1) - 1
y_start = loc(1,0) - 1
y_end = loc(1,1) - 1
; mpres at ZoomIn = True ; set up map info for zoomed area
mpres at Xstart = x_start
mpres at Ystart = y_start
mpres at Xend = x_end
mpres at Yend = y_end
;---Create the contours over the WRF map (nothing will be drawn yet).
plot = wrf_map_overlays(a,wks,contour,pltres,mpres)
;---Plot OKC Boundary
lnres = True
lnres at gsLineColor = "gray25"
lnres at gsLineThicknessF = 2.0
okc_shp = gsn_add_shapefile_polylines(wks,plot,"resources/OKCCityLimit_outline.shp",lnres)
polyres = True
polyres at gsMarkerIndex = 1 ; Filled circle
polyres at gsMarkerSizeF = 0.03
mesonet_points = gsn_add_shapefile_polymarkers(wks,plot,"resources/ok_mesonet_sites_active_20151014.shp",polyres)
micronet_points = gsn_add_shapefile_polymarkers(wks,plot,"resources/OKC_Micronet.shp",polyres)
draw(plot) ; This will draw the map and the shapefile outlines.
frame(wks) ; Advance the frame
end
From: Mary Haley [mailto:haley at ucar.edu]
Sent: Thursday, April 14, 2016 1:41 PM
To: Illston, Bradley G. <illston at ou.edu>
Cc: ncl-talk at ucar.edu; Will Hobbs <will.hobbs at utas.edu.au>
Subject: Re: [ncl-talk] Zooming Functions Clarification
Hi Brad,
There are a few problems with the script in general.
First, as Will pointed out, you are trying to set map resources when you create a contour plot. This is why you are getting errors.
But, I do see that later you are calling wrf_map_overlays, which is where you want to apply the map resources. However, with the wrf_xxxx plotting scripts, you have to be careful about zooming in on the data when it's being done over a map. The wrf_map_overlays procedure assumes that you are using the map projection that's provided on the WRF output file, and hence it doesn't really know anything about the lat/lon coordinates of your data.
If you then try to zoom in on your WRF data without telling NCL what part of your data actually corresponds to the area you are zooming in on, then your results are likely going to be incorrect.
wrf_map_overlays recognizes a special "ZoomIn" resource that allows you to do map zooming. Please see the "olr.ncl" example at:
http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Graphics/NCL/Examples/SPECIAL/olr.htm
The scripts on the "WRF debug" page also show how to use ZoomIn:
http://www.ncl.ucar.edu/Applications/wrfdebug.shtml
If you don't want to use the wrf_contour/wrf_map_overlays plotting scripts, then you can plot your WRF data with gsn_csm_contour_map. We have some examples of this, and also show how to zoom in on your data. See wrf_gsn_3.ncl at:
http://www.ncl.ucar.edu/Applications/wrfgsn.shtml
--Mary
On Wed, Apr 13, 2016 at 9:47 PM, Will Hobbs <will.hobbs at utas.edu.au<mailto:will.hobbs at utas.edu.au>> wrote:
Brad
I'm not a WRF user so any suggestion here is just a guess. However, have you tried setting the resources trYMinF, trYMaxF etc instead of mpMaxLatF etc.
I would guess that wrf_contour() is not a map plotting function, so it wouldn't recognise the mp resources. As long as the array that you're plotting has lat/lon coordinate dimensions the bounds set by the 'tr' resources should work fine.
Hope that helps
Will
From: <Illston>, "Bradley G." <illston at ou.edu<mailto:illston at ou.edu>>
Date: Thursday, 14 April 2016 1:16 PM
To: "ncl-talk at ucar.edu<mailto:ncl-talk at ucar.edu>" <ncl-talk at ucar.edu<mailto:ncl-talk at ucar.edu>>
Subject: [ncl-talk] Zooming Functions Clarification
NCL Users,
I am one to try and figure my problems on their own, but I am a bit stumped after working on this for a few days. I am trying to zoom my map in to a set of bounding latitudes and longitudes in my domain to no avail. I kept trying various iterations utilizing ZoomIn or mpMinLatF/mpMinLonF/etc. I am not sure when you should use one and when you would use the other. Below is my latest script that works, but not zoomed in. When I run it, I get the following warnings:
warning:mpLimitMode is not a valid resource in /tair_24hr_2011_2008091502_contour at this time
warning:mpMinLonF is not a valid resource in /tair_24hr_2011_2008091502_contour at this time
warning:mpMaxLonF is not a valid resource in /tair_24hr_2011_2008091502_contour at this time
warning:mpMinLatF is not a valid resource in /tair_24hr_2011_2008091502_contour at this time
warning:mpMaxLatF is not a valid resource in /tair_24hr_2011_2008091502_contour at this time
Am I mixing various gsn functions that is causing a confusion? Is there a preferred one for plotting basic WRF output (in NetCDF format) to a PNG file? Any thoughts? Thank you so much.
Cheers,
Brad Illston
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
begin
;---Define colormap. First is background color, second is foreground color
colors = (/(/255, 255, 255/),(/0, 0, 0/),(/255, 255, 255/),(/088, 164, 074/),(/047,124,062/),(/055, 072, 114/),(/095,129,183/),(/094,165,212/),(/116,196,205/),(/135,099,162/),(/128,076,144/)/) / 255.
;---Open WRF output file
a = addfile(wrf_filename,"r")
print(" NetCDF file = "+wrf_filename)
print(" Output image = "+output_png)
;---Read temperature at first time step
tc = wrf_user_getvar(a,"T2",0)
tc at long_name = "2m Air Temperature"
tc at units = "C"
tc=tc-273.15
wks = gsn_open_wks("png",output_png)
gsn_define_colormap(wks,"WhiteBlueGreenYellowRed") ; choose colormap
; gsn_define_colormap(wks,colors)
;---Resources for filled contour plot
res = True
res at cnFillOn = True
res at cnLinesOn = False
res at gsnMaximize = True
res at tiMainString = run_length + " Run (" + year + ") - " + run_date + " " + end_time + " UTC"
res at Footer = False
res at FieldTitle = "2m Air Temperature"
res at lbTitleOn = True
res at lbTitleString = ""
res at NoHeaderFooter = True ; Switch headers and footers off
res at cnLevelSelectionMode = "ExplicitLevels"
res at cnLevels = (/10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25/)
; res at ContourParameters = (/10,25,1/) ; Contour levels
res at mpLimitMode = "LatLon"
res at mpMinLatF = 35
res at mpMinLonF = -98
res at mpMaxLatF = 36
res at mpMaxLonF = -97
contour = wrf_contour(a,wks,tc,res) ; Create contour plot
pltres = True ; Basic overlay plot options
pltres at PanelPlot = True ; Tells wrf_map_overlays not to remove overlays
mpres = True ; Set map options
mpres at mpOutlineOn = True ; Turn on map outlines
mpres at mpFillOn = False ; Turn off map fill
mpres at mpDataBaseVersion = "Ncarg4_1"
mpres at mpDataSetName = "Earth..2" ; For counties
mpres at mpOutlineBoundarySets = "GeophysicalAndUSStates"
mpres at mpOutlineSpecifiers = (/"Land", "Oklahoma:counties"/)
mpres at tiMainString = run_length + " Run (" + year + ") - " + run_date + " " + end_time + " UTC"
mpres at gsnMaximize = True
;---Create the contours over the WRF map (nothing will be drawn yet).
plot = wrf_map_overlays(a,wks,contour,pltres,mpres)
end
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