Re: Array Error

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Wed, 09 Sep 2009 22:20:46 -0600

As noted in the documentation, addfiles_GetVar has been deprecated:
http://www.ncl.ucar.edu/Document/Functions/Contributed/addfiles_GetVar.shtml
ie: don't use it

addfiles is more verstile.

----
If you are trying to compute the temporal mean of the wind speed
at each grid point:
    f    = addfiles (fils, "r")
    U_GRD_221 = f[:]->U_GRD_221_HTGL_113(:,0,:,:)  ; (time,lat,lon)
    V_GRD_221 = f[:]->V_GRD_221_HTGL_113(:,0,:,:)
    WSPD      = sqrt(U_GRD_221^2 + V_GRD_221^2)
    copy_VarMeta(U_GRD_221, WSPD)
    WSPD_at_long_name = "wind speed"
    printVarSummary(WSPD)
    WSPD_AVG  = dim_avg_n_Wrap(WSPD,0)             ; (lat,lon)
    WSPD_AVG_at_long_name = "mean wind speed"
    printVarSummary(WSPD_AVG)
Dave Allured wrote:
> store = new((/wind_data,gridx_221,gridy_221/), "float")
> 
> This line makes a 3-D array of dimensions nx*ny, nx, ny.  The first 
> dimension does not seem right to me.  Should this be the time 
> dimension or the level dimension instead?
> 
> Dave Allured
> CU/CIRES Climate Diagnostics Center (CDC)
> http://cires.colorado.edu/science/centers/cdc/
> NOAA/ESRL/PSD, Climate Analysis Branch (CAB)
> http://www.cdc.noaa.gov/psd1/
> 
> DJ Rasmussen wrote:
>> Hi NCL users,
>>
>> I am attempting to make an NCL script that reads in multiple monthly 
>> NARR files with wind data and then averages them all and, finally 
>> outputs the averages to a netCDF file that I can use to make a contour 
>> plot with. To do the averages, however, I need to create an array.  For 
>> some reason, NCL will not allow me to do it the way I am trying to: by 
>> multiplying lat and lon dimensions to get the number of data points for 
>> wind values at every lat/lon on the NARR grid.
>>
>> As always, your assistance is appreciated.
>>
>> Cheers
>>
>>
>>
>>
>>
>> Using NCL version 5.1.1
>> ;*************************************************
>> ; NARRAVG.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
>>
>> ;************************************************
>> ; read in multiple grib files
>> ;************************************************
>> diri = "./" ; directory where files reside
>> fils = systemfunc("ls "+diri+"narr*.grb")
>>
>> setfileoption("grb","SingleElementDimensions","initial_time")
>>
>> f = addfiles(fils,"r"); read in all files in the folder
>>
>> ;*************************Get Variables to Average**********
>> U_GRD_221 = addfiles_GetVar(f, fils, "U_GRD_221_HTGL_113") ;Get these 
>> variables from all files
>> V_GRD_221 = addfiles_GetVar(f, fils, "V_GRD_221_HTGL_113")
>>
>> printVarSummary(U_GRD_221)
>> printVarSummary(V_GRD_221)
>>
>> dimU_GRD = dimsizes(U_GRD_221)
>>
>> gridx_221    = dimU_GRD(2)        ; get dimensions of lat
>> gridy_221    = dimU_GRD(3)
>> wind_data    = dimU_GRD(2)*dimU_GRD(3)  ; multiply lat and lon 
>> dimensions to get wind data points needed
>>
>> store = new((/wind_data,gridx_221,gridy_221/), "float")  ; create a new 
>> array for new netCDF file.
>>
>>
>> ;*************************Calculate Average******
>>
>> U_GRD_221_AVG = dim_avg_n_Wrap(U_GRD_221(:,0,:,:),0)  ; calculate 
>> average of zonal wind at level 0 for all grid points
>> V_GRD_221_AVG = dim_avg_n_Wrap(V_GRD_221(:,0,:,:),0)
>>
>>
>> wspd = sqrt( U_GRD_221_AVG2 + V_GRD_221_AVG2 )  ; calculate wind speed 
>> magnitude
>>
>>
>> ;*************create NetCDF output*******************
>> store!0    = "wspd"    ; assign named dimensions
>> store!1    = "gridx_221"
>> store!2    = "gridy_221"
>>
>> store_at_long_name = "Avg Wind Speed"
>> store_at_units     = "m/s"
>>
>> system("/bin/rm -f dailyAvg.WSPD10_NARR.nc")   ; remove any pre-existing 
>> file
>> ncdf   = addfile("dailyAvg.WSPD10_NARR.nc","c")
>> filedimdef(ncdf,"initial_time0_hours",-1,True)
>> fileattdef (ncdf, f)
>>
>> ncdf->U_GRD_221_HTGL_113 = store
>>
>> end
>>
>>
>>
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Received on Wed Sep 09 2009 - 22:20:46 MDT

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