Re: contour plot MA-ECHAM

Hi Stergios,

Sometimes if the spacing of a coordinate array is too "irregular", it
can throw NCL off and you get one of these spline messages.

I'm guessing that the spacing of 0.1 in the beginning, up to close to
100 at the end, may be a problem.

Just for fun, can you try subscripting your "u" array to
toss out some of these closely spaced levels, and see if this
makes a difference:

   plot = gsn_csm_pres_hgt(wks,u(month,{10:100},:,0),res)

You could also try adjusting the trYTensionF value, although
I'm not sure how helpful it will be in this case.

If all else fails, would you be able to provide me with your
dataset? We can do this offline.

Thanks,

--Mary

On Mon, 27 Jul 2009, Stergios Misios wrote:

> Dear all,
> I have monthly values of zonal mean zonal wind interpolated to some
> vertical layers.
> The ncdump -h gives,
>
> netcdf 02030_blz_ATM_1980-1999_zm_ymm {
> dimensions:
> lon = 1 ;
> lat = 160 ;
> lev = 45 ;
> time = UNLIMITED ; // (12 currently)
> variables:
> double lon(lon) ;
> lon:long_name = "longitude" ;
> lon:units = "degrees_east" ;
> lon:standard_name = "longitude" ;
> double lat(lat) ;
> lat:long_name = "latitude" ;
> lat:units = "degrees_north" ;
> lat:standard_name = "latitude" ;
> double lev(lev) ;
> lev:long_name = "pressure" ;
> lev:units = "Pa" ;
> lev:positive = "down" ;
> double time(time) ;
> time:units = "months since 1900-01-01 12:00" ;
> time:calendar = "proleptic_gregorian" ;
> float t(time, lev, lat, lon) ;
> t:long_name = "temperature" ;
> t:units = "K" ;
> t:code = 130 ;
> t:table = 128 ;
> t:grid_type = "gaussian" ;
> float u(time, lev, lat, lon) ;
> u:long_name = "u-velocity" ;
> u:units = "m/s" ;
> u:code = 131 ;
> u:table = 128 ;
> u:grid_type = "gaussian" ;
> ======================================
> and the vertical layers are
> lev = 1000, 925, 850, 775, 700, 600, 500, 400, 300, 250, 200, 150, 100, 90,
> 80, 70, 60, 50, 40, 30, 20, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.9, 0.8,
> 0.7,
> 0.5, 0.4, 0.3, 0.1, 0.09, 0.08, 0.07, 0.05, 0.03, 0.02, 0.01 ;
> ======================================
> I am trying simply to plot in a pressure/latitude sections with
> gsn_csm_pres_hgt but
> the spline interpolation is getting crazy and says something like,
>
> warning:_NhlCreateSplineCoordApprox: Attempt to create spline
> approximation for Y axis failed: consider adjusting trYTensionF value
> warning:IrTransInitialize: error creating spline approximation for
> trYCoordPoints; defaulting to linear
> warning:_NhlCreateSplineCoordApprox: Attempt to create spline
> approximation for Y axis failed: consider adjusting trYTensionF value
> warning:IrTransSetValues: error creating spline approximation for
> trYCoordPoints; defaulting to linear
> warning:_NhlCreateSplineCoordApprox: Attempt to create spline
> approximation for Y axis failed: consider adjusting trYTensionF value
> warning:IrTransSetValues: error creating spline approximation for
> trYCoordPoints; defaulting to linear
> warning:_NhlCreateSplineCoordApprox: Attempt to create spline
> approximation for Y axis failed: consider adjusting trYTensionF value
> ===================================================================================================
> Of course i am getting a plot but is incorrect. What i am missing? What
> i am doing wrong?
> the print(dvar&lev) gives,
>
> Variable: lev (coordinate)
> Type: double
> Total Size: 360 bytes
> 45 values
> Number of Dimensions: 1
> Dimensions and sizes: [lev | 45]
> Coordinates:
> Number Of Attributes: 3
> positive : down
> units : Pa
> long_name : pressure
> (0) 1000
> (1) 925
> (2) 850
> (3) 775
> (4) 700
> (5) 600
> (6) 500
> (7) 400
> (8) 300
> (9) 250
> (10) 200
> (11) 150
> (12) 100
> (13) 90
> (14) 80
> (15) 70
> (16) 60
> (17) 50
> (18) 40
> (19) 30
> (20) 20
> (21) 10
> (22) 9
> (23) 8
> (24) 7
> (25) 6
> (26) 5
> (27) 4
> (28) 3
> (29) 2
> (30) 1
> (31) 0.9
> (32) 0.8
> (33) 0.7
> (34) 0.5
> (35) 0.4
> (36) 0.3
> (37) 0.1
> (38) 0.09
> (39) 0.08
> (40) 0.07000000000000001
> (41) 0.05
> (42) 0.03
> (43) 0.02
> (44) 0.01
> The level 40 looks very odd. The original value is 0.07
>
> I have attached my script. Thank you in advance.
>
>
>
> Regards,
> Stergios
>
>
>
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Received on Mon Jul 27 2009 - 08:15:02 MDT