Re: correlation error (WRF vs. Obs)

From: Will Hobbs <whobbs_at_nyahnyahspammersnyahnyah>
Date: Fri, 02 Nov 2007 10:09:55 PDT
('binary' encoding is not supported, stored as-is) Erik

I notice that the way you have written your v2 subscript implies normal
subscripting, but since your values for lonW and latS are negative I
assume you intend to use coordinate subscripting.

Try changing your lat and lon bounds to float, i.e.
 lonW = -35.
 lonE = 35.
 latN = 35.
 latS = -20.

and use curly brackets when subscripting v2 :

ccr = esccr(v_plane,v2({700}, {latN:latS} , {lonE:lonW}),maxlag)

I hope that helps, no doubt Denis or Adam will give you a much better
answer soon!

Will

On Thu, 1 Nov 2007 23:42:22 -0400 "Erik Noble" wrote:

> Dear NCL world.
> I am trying to do a correlation between v at 700mb from WRF data and
> reanalysis data.
>
> I use the function ccr =
> esccr(v_plane,v2({700},latN:latS,lonE:lonW),maxlag) similar to
> example 1 at: http://www.ncl.ucar.edu/Applications/corel.shtml
> I get the error:
> fatal:An error occurred reading v2
> fatal:Execute: Error occurred at or near line 60 in file
> Test_WRF_FNL_Corr.ncl
>
> Am I calling this variable incorrectly? Below are both the errors and
> my code. The PrintVarSummary(v2) shows that the v2 variable ha sthe
> following dimensions :
> Dimensions and sizes: [lv_ISBL3 | 26] x [lat_3 | 181] x [lon_3 | 360]
>
> Any advice would be greatly appreciated.
> -Erik
>
>
>
> Copyright (C) 1995-2007 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 4.3.1
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
>
> Variable: times
> Type: string
> Total Size: 3896 bytes
> 487 values
> Number of Dimensions: 1
> Dimensions and sizes: [487]
> Coordinates:
> Number Of Attributes: 2
> description : times in file
> _FillValue : missing
>
> (0) Working on time: 2006-09-11_00:00:00
>
>
> Variable: v
> Type: float
> Total Size: 1636308 bytes
> 409077 values
> Number of Dimensions: 3
> Dimensions and sizes: [27] x [109] x [139]
> Coordinates:
> Number Of Attributes: 2
> description : v Velocity
> units : m/s
>
>
> Variable: v_plane
> Type: float
> Total Size: 60604 bytes
> 15151 values
> Number of Dimensions: 2
> Dimensions and sizes: [109] x [139]
> Coordinates:
> Number Of Attributes: 6
> lon2d : <ARRAY of 15151 elements>
> lat2d : <ARRAY of 15151 elements>
> description : v Velocity
> units : m/s
> _FillValue : -999999
> PlotLevelID : 700 hPa
>
>
> Variable: v2
> Type: float
> Total Size: 6776640 bytes
> 1694160 values
> Number of Dimensions: 3
> Dimensions and sizes: [lv_ISBL3 | 26] x [lat_3 | 181] x [lon_3 | 360]
> Coordinates:
> lv_ISBL3: [10..1000]
> lat_3: [90..-90]
> lon_3: [ 0..359]
> Number Of Attributes: 12
> center : US National Weather Service - NCEP (WMC)
> long_name : v-component of wind
> units : m/s
> _FillValue : -999
> level_indicator : 100
> grid_number : 3
> parameter_table_version : 2
> parameter_number : 34
> model : Spectral Statistical Interpolation (SSI) analysis from
> "Final" run.
> forecast_time : 0
> forecast_time_units : hours
> initial_time : 09/13/2006 (00:00)
>
>
> Variable: v2
> Type: float
> Total Size: 6776640 bytes
> 1694160 values
> Number of Dimensions: 3
> Dimensions and sizes: [lv_ISBL3 | 26] x [lat_3 | 181] x [lon_3 | 360]
> Coordinates:
> lv_ISBL3: [10..1000]
> lat_3: [90..-90]
> lon_3: [-180..179]
> Number Of Attributes: 13
> lonFlip : longitude coordinate variable has been reordered via lonFlip
> initial_time : 09/13/2006 (00:00)
> forecast_time_units : hours
> forecast_time : 0
> model : Spectral Statistical Interpolation (SSI) analysis from
> "Final" run.
> parameter_number : 34
> parameter_table_version : 2
> grid_number : 3
> level_indicator : 100
> units : m/s
> long_name : v-component of wind
> center : US National Weather Service - NCEP (WMC)
> _FillValue : -999
> fatal:Subscript out of range, error in subscript #1
>
> fatal:An error occurred reading v2
>
> fatal:Execute: Error occurred at or near line 60 in file
> Test_WRF_FNL_Corr.ncl
>
>
***NCL****Code************************************************************
***********************
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> ; This creates a cross-correlation of v at 700mb between WRF output
> and FNL reanalysis data
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
>
> begin
>
> a=addfile("../../WRF-SOP3_Athena_3_1_2.nc","r")
> ; Which times and how many time steps are in this data set?
> times = wrf_user_list_times(a) ; get times in the file
> ntimes = dimsizes(times) ; number of times in the file
>
> lonW = -35
> lonE = 35
> latN = 35
> latS = -20
>
> pressure = 700.
>
> times = wrf_user_list_times(a)
> do it = 328,328 ;;;;;Time step you want!!!!
> print("Working on time: " + times(it) )
>
> v = wrf_user_getvar(a,"va",it) ; v averaged to mass points
> p = wrf_user_getvar(a, "pressure",it) ; pressure
>
> v_plane = wrf_user_intrp3d( v,p,"h",pressure,0.,False)
> v_plane_at_lat2d = a->XLAT(0,:,:) ; do you need XLAT_V, or XLAT?
> v_plane_at_lon2d = a->XLONG(0,:,:) ; do you need XLONG_V, or XLONG?
>
> printVarSummary(v)
> printVarSummary(v_plane)
>
> ;;;;;;;;;;;;;;;;;;;;;; 2nd file
> b=addfile("../../Boundary_Data/FNL_SOP3/FNL_09_grb/fnl_060913_00_00.grb","r")
> ;FILES = systemfunc ("csh -c ' ls "+ "FNL*.nc'") ; root of data
> file you want to plot
> ;numFILES = dimsizes(FILES)
> ;do ifil = 0, numFILES-1 ; BIG FILES LOOP ; NEW file loop
> ;b = addfile(FILES(ifil)+".nc","r")
>
> ; First get the variables we will need
> v2 = b->V_GRD_3_ISBL_10 ; V_Wind
> printVarSummary( v2 ) ; before lonFlip
> v2 = lonFlip( v2 )
> lon2d_Flip=v2&lon_3
> printVarSummary( v2 ) ; after lonFlip
>
>
> ;************************************************
> ; calculate cross correlations
> ;************************************************
> maxlag = 25 ; set lag
> ; note, the max lag should not be more than N/4
>
> ccr = esccr(v_plane,v2({700},latN:latS,lonE:lonW),maxlag)
> ; calc cross cor
> x = ispan(0,maxlag-1,1) ; define x axis
> ;************************************************
>
> end do
> end
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> ncl-talk_at_ucar.edu
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============================
Will Hobbs
PhD Candidate
Room A113
UCLA Department of Geography
1255 Bunche Hall
Los Angeles CA 90095-1524
Tel: 310 663 2631

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Received on Fri Nov 02 2007 - 11:09:55 MDT

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