[ncl-talk] Problems Plotting NARR data

[Mary Haley]

Hi Kerwyn,

In the future, it would help if you could provide the output of doing:

printVarSummary(temp)
printVarSummary(hgt)
etc.

so we know what your variables look like.

1. If "temp" is a 3D array with pressure level as its leftmost dimension,
and if the "level" dimension of "temp" is represented by a level coordinate
array that's already in hPA units, then you should be able to use
coordinate subscripting to get the level you want:

temp = a->TMP_221_ISBL({600},:,:)      ; The use of { and } specifies that
you want to subset based on coordinate values, rather than index values
u_wind = a->U_GRD_221_ISBL({600},:,:)

2. To zoom in on the map, you don't want to tell NCL that you are using the
native projection. This means you do NOT want to set tfDoNDCOverlay to
True.  Just remove this or comment it out, because it is False by default.

For a better understanding of plotting data in a native projection and a
non-native projection, see example dataonmap_native_4.ncl at:

http://www.ncl.ucar.edu/Applications/plot_data_on_map.shtml#ex4native

3. I think the fatal error is occurring because you were trying to plot a
3D array.  Once you do #1 and subscript temp, u, and v as described, then
you should end up with 2D arrays that you can create contour and vector
plots from.

If you continue to have problems, please post back to ncl-talk.  It would
also help if we could have your data and the latest version of your script.

Thanks,

--Mary





On Sat, Jul 30, 2016 at 10:13 PM, Kerwyn Texeira <ktish86 at gmail.com> wrote:

> Hi ncl-talk,
>
> I'm trying to plot and overlay of (NARR) North American Regional
> Reanalysis temperature, geopotential height contours, and wind barbs at
> 600mb but I'm running into some problems.
>
> 1.  Where on the script should I mention the pressure level eg 600hpa so
> that both the temperature, wind barbs and geopotential heights can be
> plotted at this level that level?
>
> 2. How do I zoom into an area?  I specified the min lat, lon and max lat,
> lon but it seems not to zoom into the area of interest?
>
> 3. I do not understand why I'm getting the following error:
>
>  (0)     gsn_csm_contour_map_ce: Fatal: the input data array must be 1D or
> 2D
> fatal:Illegal right-hand side type for assignment
> fatal:["Execute.c":8578]:Execute: Error occurred at or near line 113 in
> file narr_temp.ncl
>
> My script:
>
> 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/csm/contributed.ncl"
>
> begin
> a = addfile("./narr-a_221_20140128_0000_000.grb", "r")
>
> wks_type = "png"
> wks_type at wkWidth = 2500
> wks_type at wkHeight = 2500
>
> wks= gsn_open_wks(wks_type, "temp_narr")
> gsn_define_colormap(wks,"matlab_jet")
>
> lat2d = a->gridlat_221
> lon2d = a->gridlon_221
> hgt = a->HGT_221_ISBL
> temp = a->TMP_221_ISBL
> pres = a->PRES_221_HYBL
> u_wind = a->U_GRD_221_ISBL
> v_wind = a->V_GRD_221_ISBL
> lev    = a->lv_ISBL3            ; 29 levels
>
> spd = (u_wind*u_wind + v_wind*v_wind)^(0.5) ; m/s
>
> pres = pres*0.01  ; converts to hpa
>
> u_wind = u_wind*1.94384449
> v_wind = v_wind*1.94384449
>
> temp = temp - 273
>
> temp at lat2d = lat2d
> temp at lon2d = lon2d
>
> hgt at lat2d = lat2d
> hgt at lon2d = lon2d
>
> pres at lon2d = lon2d
> pres at lat2d = lat2d
>
> u_wind at lon2d = lon2d
> u_wind at lat2d = lat2d
>
> spd = spd*1.94384449
>
> spd at lon2d = lon2d
> spd at lat2d = lat2d
>
> v_wind at lat2d = lat2d
> v_wind at lon2d = lon2d
>
>
> res = True
> res at gsnDraw = False
> res at gsnFrame = False
> res at cnLineLabelsOn = False
> res at cnFillOn = True
> res at tiMainString = "Temperature (C) at 700hpa on Jan 28 at 00:00UTC"
> res at tiMainFont = "helvetica"
> res at tiMainFontHeightF = 0.02
> res at pmTickMarkDisplayMode = "Always"
> res at mpProjection = "CylindricalEquidistant"
> res at mpOutlineOn = "True"
> res at lbOrientation = "Vertical"
> res at tiMainOffsetYF = -0.03
> res at mpFillOn  = False
> res at tfDoNDCOverlay = True
> res at mpMinLatF = 37.85
> res at mpMaxLatF = 38.50
> res at mpMinLonF = -120.0
> res at mpMaxLonF = -119.0
> res at gsnLeftString = "Geopotential Height (m) and Winds (kts)"
> res at gsnStringFontHeightF = 0.020
> res at gsnRightString = ""
> res at gsnMaximize = True
> res at mpShapeMode = "FreeAspect"
> res at lbTitleString = "Temperature (C)"
> res at lbTitlePosition = "Right"
> res at lbTitleFontHeightF = 0.020
> res at gsnAddCyclic = False
> ;res at cnLevelSelectionMode = "ManualLevels"
> ;res at cnMinLevelValF =
> ;res at cnMaxLevelValF =
> ;res at cnLevelSpacingF =
>
> res1 = True
> res1 at gsnDraw = False
> res1 at gsnFrame = False
> res1 at vcWindBarbLineThicknessF = 7.0
> res1 at vcRefLengthF = 0.018
> res1 at vcRefMagnitudeF = 10
> res1 at vcMinDistanceF = 0.05
> res1 at vcGLyphStyle = "WindBarb"
> res1 at gsnRightString =""
> res1 at vcRefAnnoOn = False
> res1 at gsnAddCyclic = False
>
> res2 = True
> res2 at gsnDraw = False
> res2 at gsnFrame = False
> res2 at cnLineColor = "Black"
> res2 at gsnContourLineThicknessesScale = 5.0
> res2 at gsnAddCyclic = False
> res2 at tfDoNDCOverlay = True
> res2 at gsnLeftString = ""
> res2 at gsnRightString = ""
> res2 at cnInfoLabelOn = False
> ;res2 at cnLevelSpacingF = 2
> res2 at cnLineLabelBackgroundColor = "white"
> res2 at cnLineLabelDensityF = 1
>
> geo = gsn_csm_contour(wks, hgt, res2)
>
> temp = gsn_csm_contour_map(wks, temp, res)
>
> vector = gsn_csm_vector(wks, u_wind, v_wind, res1)
>
> overlay(temp, geo)
> overlay(temp, vector)
>
> draw(temp)
> frame(wks)
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> end
>
> Whatever help anyone can give to me will be greatly appreciated. I thank
> you very much in advance!!!.
>
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