Dear Adam,
Using gsn_csm_contour provided a quick and dirty solution to getting
something plotted. However, the way it is plotted makes the results
very hard to interpret. I really need to interpolate onto sensible
pressure/height levels to be able to understand what is going on.
The major problem is I cant work out how to do an interpolation of
multiple files simultaneously. The functions "addfiles" and
"addfiles_GetVar" in my script seem to nicely open all the files at
once, and select the same variables out of each file for further
processing. However, I also need to interpolate the results in all
the files onto the pressure height grid before the further processing.
I am not sure how to do this. I assume that a variable such as U will
interpolate differently onto the grid for each file. I am not sure if
the addfiles routine can be used in any way to do this ?. Or do I
need to interpolate each file one by one using a do loop ?. If I use
a do loop, how do I tell the script which file I am referring to in
the do loop ?.
Do I need to store the interpolated data in separate arrays for each
interpolated file ?. Do I store the interpolated data in a different
new file for each file I am interpolating, and then read in the new
files ?. (the interpolation routine I have used before for a single
file appears to store some output into a new separate file).
Does anyone know how to do this ?.
I enclose the lines I have used before to do interpolation of a
single file, followed by the script I am currently using.
Thanks,
Helen.
1) Here are the lines I have used before to interpolate a single file :
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
begin
; input file
diri = "./"
fili = "zeusorigspongej.cam2.h0.0038-11-21-00000.nc"
fi = addfile (diri+fili, "r")
; output file
diro = "./"
filo = "helen.nc"
system ("/bin/rm -f "+diro+filo) ; remove any pre-exist file
fo = addfile (diro+filo, "c")
; add any file attributes
fo_at_title = fi_at_title + ": Selected Variables at pressure levels"
fo_at_history = systemfunc ("date")
fo_at_source = fi_at_source
fo_at_case = fi_at_case
fo_at_Conventions = fi_at_Conventions
Var = (/ "T" , "Q", "U", "V"/) ; select variable to be
interpolated.
nVar = dimsizes (Var)
; desired output levels
lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
20000., 10000., 5000., 3000., 1500., 750., 390., 200., 100., 50.,25.,
14., 7., 3.5, 1.9, 0.95, 0.4, 0.1, 0.03 /)
lev_p!0 = "lev_p" ; variable and dimension name
the same
lev_p&lev_p = lev_p ; create coordinate variable
lev_p_at_long_name = "pressure" ; attach some attributes
lev_p_at_units = "hPa"
lev_p_at_positive = "down"
hyam = fi->hyam ; read hybrid info
hybm = fi->hybm
PS = fi->PS
P0mb = 0.01*fi->P0
do n=0,nVar-1 ; loop over the variables
X = fi->$Var(n)$
Xp = vinth2p (X, hyam, hybm, lev_p ,PS, 1, P0mb, 2, True)
copy_VarAtts(X, Xp)
fo->$Var(n)$ = Xp ; write to netCDF file
print (Var(n)+": interpolated and written to netCDF")
end do
end
2) Here is my current script, which processes multiple files :
;***********************
; timely.ncl
;***********************
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
; Keep all files open when have a lot of files :
setfileoption("nc","SuppressClose",False)
diri = "./"
; fili = systemfunc("cd "+diri+" ; ls zeusorigspongej*.cam2.h0*nc")
; fili = systemfunc("cd "+diri+" ; ls
zeusrand09125daily*.cam2.h0*nc")
fili = systemfunc("cd "+diri+" ; ls rand09125*.cam2.h0*nc")
f = addfiles (fili,"r")
U = addfiles_GetVar(f,fili,"U")
lat = addfiles_GetVar(f,fili,"lat")
lon = addfiles_GetVar(f,fili,"lon")
lev = addfiles_GetVar(f,fili,"lev")
time = addfiles_GetVar(f,fili,"time")
printVarSummary( U )
dimu = dimsizes( U )
ntim = dimu(0)
klvl = dimu(1)
nlon = dimu(2)
mlon = dimu(3)
uavg = dim_avg_Wrap(U)
uavg_reverse = uavg(lev | :, time | :, lat | :)
;***********************
; Create Plot
;***********************
wks = gsn_open_wks ("pdf", "presstimetest" ) ; open
workstation
gsn_define_colormap(wks,"rainbow") ; choose colormap
res = True
res_at_cnFillOn = True
res_at_lbLabelAutoStride = True
res_at_gsnMaximize = True ; if [ps, eps, pdf] make large
res_at_gsnSpreadColors = True ; span color map
nl = 96
res_at_gsnCenterString = "zeusorigspongej381121"
;; plot = gsn_csm_pres_hgt(wks, uavg(nt,:,:), res ) ; (lev,lat)
; plot = gsn_csm_pres_hgt(wks, uavg_reverse(:,:,nl), res ) ;
(time,lev,lat)
plot = gsn_csm_contour(wks, uavg_reverse(:,:,nl), res ) ;
(time,lev,lat)
res_at_trYReverse = True
end
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Received on Wed Feb 25 2009 - 03:42:20 MST
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