Re: Angle represented in a CrossSection figure

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Fri Nov 04 2011 - 06:59:58 MDT

Hello Yan, This question is more appropriate for wrfhelp@ucar.edu
             It has been forwarded.
Good Luck

On 11/4/11 12:22 AM, Yan Bao wrote:
> Hi, NCL group,
> I've been tried to make a CrossSection figure along the instant
> wind direction (angle), but found
> the angle I calculated was unproperly represented in the figure when
> the wind direction were greater than
> 315 degree, which makes me so confused. For instance, in the figure
> (attachment) the angle I calculated was
> 322 degree which is supposed to point northwest direction (red arrow),
> but actually it was shown in the
> figure with southwest direction (red line).I'm not sure if I did
> something wrong or something else happened.
> Here I post part of my script related and the figure, hope any one who
> knows about it can give me some
> suggestions. Thanks.
>
>
> dir="/OUTPUT/"
> fn = "wrfout_d01_2008-06-07_00:00:00.nc <http://00.nc>"
> a = addfile(dir+fn,"r")
> wks = gsn_open_wks("pdf","test")
> xlat = wrf_user_getvar(a, "XLAT",0)
> xlon = wrf_user_getvar(a, "XLONG",0)
> ter = wrf_user_getvar(a, "HGT",0)
>
> ; Set some basic resources
> res = True
> res@Footer = False
> res@vpWidthF = 0.75 ; overwrite basic plot size
> res@vpHeightF = 1.0
> pltres = True
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> FirstTime = True
> FirstTimeMap = True
> times = wrf_user_list_times(a) ; get times in the file
> ntimes = dimsizes(times) ; number of times in the file
> xlat = wrf_user_getvar(a, "XLAT",0)
> xlon = wrf_user_getvar(a, "XLONG",0)
> ter = wrf_user_getvar(a, "HGT",0)
> do it = 7,7,1 ; TIME LOOP
> print("Working on time: " + times(it) )
> res@TimeLabel = times(it) ; Set Valid time to use on plots
> pm10 = wrf_user_getvar(a,"PM10",it) ; T in C
> uvm = wrf_user_getvar(a,"uvmet",it) ; umet and vmet averaged to
> mass points
>
> u = uvm(0,:,:,:)
> v = uvm(1,:,:,:)
>
> y1 = 28
> x1 = 7
> plane = (/y1,x1/)
>
> opts = False
> r2d = 45.0/atan(1.0) ; conversion factor (radians to degrees)
>
> u1 = u(0,y1,x1)
> v1 = v(0,y1,x1)
> angle = atan2(u1, v1) * r2d + 180 ; ===> dir = 225.0
> print(angle) ; 322
> ....
> ; MAKE PLOTS
> plot = new(10,graphic)
> if (FirstTimeMap) then
> lat_plane = wrf_user_intrp2d(xlat,plane,angle,opts)
> lon_plane = wrf_user_intrp2d(xlon,plane,angle,opts)
> mpres = True
> pltres = True
> pltres@FramePlot = False
> optsM = res
> optsM@NoHeaderFooter = True
> optsM@cnFillOn = True
> optsM@lbTitleOn = False
> contour = wrf_contour(a,wks,ter,optsM)
> plot(0) = wrf_map_overlays(a,wks,(/contour/),pltres,mpres)
> lnres = True
> lnres@gsLineThicknessF = 3.0
> lnres@gsLineColor = "Red"
> do ii = 0,dimsX(0)-2
>
> gsn_polyline(wks,plot(0),(/lon_plane(ii),lon_plane(ii+1)/),(/lat_plane(ii),lat_plane(ii+1)/),lnres)
> end do
> frame(wks)
> delete(lon_plane)
> delete(lat_plane)
> pltres@FramePlot = True
> end if
> end do
>
>
> Yan
>
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Received on Fri Nov 4 07:00:05 2011

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