Re: unit attributes problem

Hi Uma,

I think what's missing is that the "lev" coordinate array that's
attached to your variable doesn't have the units attribute attached to
it before you assign it to T.

You have:

       T&lev = lev
       lev_at_units = "mb" lev_at_longname = "pressure"

try this instead:

       lev_at_units = "mb" lev_at_longname = "pressure"
       T&lev = lev

This way, T&lev_at_units will be "mb".

Just FYI: when you do:

       T&lev = lev

and then later make changes to "lev", these changed
will not affect T&lev. T&lev and lev are two separate variables.

--Mary

On Fri, 13 Oct 2006, Uma S. Bhatt wrote:

> Hi NCL folks,
>
> I have put together an NCL program to read in an array of radiosonde data
> (18 levels, and 49 Januarys) and want to make a contour pressure vs time
> plot. The data seems to be read in correctly and I can make a plain contour
> plot (commented out part below with the heading PLOT 1). But when I try to
> plot using pressure on one of the axis I get the following error:
> --------
> 0) gsn_csm_pres_hgt: Fatal: The coordinate array for the first dimension
> of the input data must be in Pascals, Hecto-pascals, or millibars
> (0) and it must contain the attribute 'units' set to one of the following
> strings (depending on your units):
> (0) 'mb' 'Mb' 'MB' 'millibar' 'millibars' 'MILLIBARS'
> 'hybrid_sigma_pressure' 'Pa' 'pa' 'PA' 'Pascals' 'pascals' 'PASCALS' 'hpa'
> 'hPa' 'HPA' 'hecto-pascals' 'HECTO-PASCALS'
> (0) Cannot create plot.
> fatal:Illegal right-hand side type for assignment
> fatal:Execute: Error occurred at or near line 89
> --------
> The lev array has units of mb. I tried several of the different spellings
> as well converting to Pa. But I get the same message. Help!
>
> Thanks,
> Regards,
> Uma
>
>
> My full screen dump and program are below:
>
> --------------------------------------
> [Uma-Bhatts-Computer-2:AK_climate/radiosonde.data/contour.plots] bhatt% ncl <
> contour.ncl
> Copyright (C) 1995-2006 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 4.2.0.a033
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
>
>
> Variable: lev
> Type: integer
> Total Size: 72 bytes
> 18 values
> Number of Dimensions: 1
> Dimensions and sizes: [18]
> Coordinates:
> Number Of Attributes: 2
> longname : pressure
> units : mb
>
>
> Variable: T
> Type: float
> Total Size: 3528 bytes
> 882 values
> Number of Dimensions: 2
> Dimensions and sizes: [lev | 18] x [time | 49]
> Coordinates:
> lev: [1013..5]
> time: [1957..2005]
> Number Of Attributes: 3
> long_name : FAI Temperature
> units : K
> _FillValue : -999
>
>
> Variable: slice
> Type: float
> Total Size: 3528 bytes
> 882 values
> Number of Dimensions: 2
> Dimensions and sizes: [lev | 18] x [time | 49]
> Coordinates:
> lev: [1013..5]
> time: [1957..2005]
> Number Of Attributes: 3
> _FillValue : -999
> units : K
> long_name : FAI Temperature
>
>
> Variable: lev
> Type: integer
> Total Size: 72 bytes
> 18 values
> Number of Dimensions: 1
> Dimensions and sizes: [18]
> Coordinates:
> Number Of Attributes: 2
> longname : pressure
> units : mb
> (0) 1013
> (1) 1000
> (2) 850
> (3) 700
> (4) 500
> (5) 400
> (6) 300
> (7) 200
> (8) 250
> (9) 150
> (10) 100
> (11) 70
> (12) 50
> (13) 30
> (14) 20
> (15) 10
> (16) 7
> (17) 5
> (0) gsn_csm_pres_hgt: Fatal: The coordinate array for the first dimension
> of the input data must be in Pascals, Hecto-pascals, or millibars
> (0) and it must contain the attribute 'units' set to one of the following
> strings (depending on your units):
> (0) 'mb' 'Mb' 'MB' 'millibar' 'millibars' 'MILLIBARS'
> 'hybrid_sigma_pressure' 'Pa' 'pa' 'PA' 'Pascals' 'pascals' 'PASCALS' 'hpa'
> 'hPa' 'HPA' 'hecto-pascals' 'HECTO-PASCALS'
> (0) Cannot create plot.
> fatal:Illegal right-hand side type for assignment
> fatal:Execute: Error occurred at or near line 89
> --------------------------------------------------------------------
>
> My Program is a combination of the ascii read conwomap_2.ncl and a
> pressure/height vs. Time plot h_time_3.ncl.
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> [Uma-Bhatts-Computer-2:AK_climate/radiosonde.data/contour.plots] bhatt% cat
> contour.ncl
> ;================================================;
> ; conwomap_2.ncl
> ;================================================;
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" load
> "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" ;
> ================================================;
> begin
> ;=================================================;
> ; open file and read in ascii data
> ;=================================================;
> ;&& declare the new variable T and prep to read it in
> lev =(/1013,1000,850,700,500,400,300,200,250,150,100,\
> 70,50,30,20,10,7,5 /)
> time = (/1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, \
> 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, \
> 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, \
> 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, \
> 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, \
> 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 /)
> ; 1) Radiosonde Temperatures
> ; declare the new variable
> ; row and column
> T = new((/18,49/),float)
> T!0="lev"
> T!1="time"
>
> T&lev = lev
> lev_at_units = "mb" lev_at_longname = "pressure"
>
> printVarSummary(lev)
> T&time = time
> time_at_units = "years"
> time_at_longname = "time"
>
> T_at_units = "K"
> T_at_long_name = "FAI Temperature"
> T@_FillValue = -999. printVarSummary(T)
>
> ;&& enter numbers and give meta data for data
> ; rows and then columns
> T=asciiread("Dect_p.txt",(/18,49/),"float")
> ;=================================================;
> ; PLOT 1
> ;=================================================;
> ; wks = gsn_open_wks("ps","conwomap") ; open a ncgm file
> ; gsn_define_colormap(wks,"gui_default") ; choose a colormap
> ;
> ; res = True ; plot mods desired
> ;
> ; res_at_cnFillOn = True ; turn on color
> ; res_at_gsnSpreadColors = True ; use full range of colormap
> ;
> ;; res_at_vpWidthF = 0.5 ; change aspect ratio of plot
> ;; res_at_vpHeightF = 0.3
> ;
> ; plot = gsn_csm_contour(wks,T,res) ; contour the variable
> ;
> ;=================================================;
> ; PLOT 2
> ;=================================================;
> ;================================================
> ; smooth data
> ;================================================
> wgt = (/ 1., 3., 4., 3., 1./) ; wgts for temporal smooth
> wgt = wgt/sum(wgt) ; normalize
>
> slice = T
> slice = wgt_runave(T, wgt, 0)
> printVarSummary(slice)
> ;================================================
> ; plot
> ;================================================
> wks = gsn_open_wks ("ps", "h_time") ; open ps file
> gsn_define_colormap(wks,"BlWhRe") ; choose colormap
> res = True ; plot mods desired
>
> res_at_cnFillOn = True ; turn on color
> res_at_cnLinesOn = False ; no contour lines
> res_at_gsnSpreadColors = True ; use full range of colors
> res_at_lbLabelAutoStride = True ; optimal labels
>
> res_at_cnLevelSelectionMode = "ManualLevels" ; set manual contour levels
> res_at_cnMinLevelValF = -70. ; set min contour level
> res_at_cnMaxLevelValF = 10. ; set max contour level
> res_at_cnLevelSpacingF = 5. ; set contour spacing
> print(lev) plot = gsn_csm_pres_hgt (wks,slice,res)
>
> end
>
> --
> Uma S. Bhatt
> Assoc. Professor
> Geophysical Institute
> IARC Room 307 University of Alaska Fairbanks
> 903 Koyukuk Dr. Fairbanks, Alaska 99775-7320
> tel: (907) 474-2662 fax: (907) 474-2643
> bhatt_at_gi.alaska.edu
> www.gi.alaska.edu/~bhatt/
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Received on Fri Oct 13 2006 - 14:00:39 MDT