[ncl-talk] NCL plot problem with ascii data

MM Ali mmali110 at gmail.com
Fri Apr 5 07:56:20 MDT 2019 

I too hVe have 6.5.0 version installed in one of the Florida state
university. There should no be an installation problem but something
different. It would be great if you can help in this. Do I have to set any
environment?

On Fri, Apr 5, 2019, 17:25 Dennis Shea <shea at ucar.edu> wrote:

> I used NCL 6.5.0 The oldest version of NCL that I have available is 6.3.0
> [4+ years old].
>
> The script runs on both versions. There is no way to retrofit to an old
> version.
>
> %> ncl -V
> %> uname -a
>
> will provide useful information
>
> Ypu must post installation questions to the ncl-install at ucar.edu to which
> you must subscribe. See
>
> *http://www.ncl.ucar.edu/Support/email_lists.shtml*
> <http://www.ncl.ucar.edu/Support/email_lists.shtml>
>
> I do not help with installation questions.
>
> Good luck
>
>
> On Thu, Apr 4, 2019 at 9:13 PM MM Ali <mmali110 at gmail.com> wrote:
>
>> Hello Dennis,
>>
>> Thank you very much for your elaborate explanation and particularly for
>> correcting my manuscript. When I ran the edited code, I get the following
>> error:
>>
>> fatal:Cannot create triangular mesh: supply additional resources or build
>> with Triangle package
>> fatal:ContourPlotDraw: draw error
>> fatal:ContourPlotDraw: draw error
>> fatal:PlotManagerDraw: error in plot draw
>> fatal:_NhlPlotManagerDraw: Draw error
>> fatal:Cannot create triangular mesh: supply additional resources or build
>> with Triangle package
>> fatal:ContourPlotDraw: draw error
>> fatal:ContourPlotDraw: draw error
>> fatal:PlotManagerDraw: error in plot draw
>> fatal:_NhlPlotManagerDraw: Draw error
>>
>> Please suggest the changes in the code.
>>
>> Best regards
>> Ali
>>
>> On Fri, Apr 5, 2019 at 5:44 AM Dennis Shea <shea at ucar.edu> wrote:
>>
>>> As ncl-talk always mentions: The 1st rule of data processing is: *Look
>>> at your data!*
>>>
>>> [1]
>>> The data look like they are sub-sampled from a gridded dataset. Given
>>> the distribution of the locations, I would call this a 'ragged-2d-array.'
>>> Specifically: each latitude  has a different number of points; each
>>> longitude has a different number of points. See plots.
>>>
>>> [2]
>>> Due to the ordering of the values on the ascii file, coordinate value
>>> syntax [ *&* ] should not be used. Specifically, the latitude and
>>> longitude values are not monotonic which is a requirement for coordinate
>>> arrays.
>>>
>>> [3]
>>> The the values are between 100E and 70W. For a limited region, I find is
>>> easier in this instance to use all positive longitudes [or all negative
>>> longitudes]. Hence, I changed a longitude range of 100 to 290.
>>>
>>> longitude = *where*
>>> <http://www.ncl.ucar.edu/Document/Functions/Built-in/where.shtml>(longitude.lt.0,
>>> longitude+360, longitude)
>>>
>>> [4]
>>>
>>> For graphics, NCL requires ragged arrays to be treated as an array of
>>> random locations [eg: station data].
>>>
>>>   res*@*sfXArray = longitude  ; data values are irregularly spaced
>>>   res*@*sfYArray  = latitude
>>>
>>> [5]
>>>
>>> The *gsn_coordinates* graphics utility which plot markers at each
>>> location requires that the 1d latitude/longitude be attributes to the
>>> variable being plotted:
>>>
>>>   variable*@lon1d*  = longitude
>>>   variable*@lat1d*   = latitude
>>> *  gsn_coordinates
>>> <http://www.ncl.ucar.edu/Document/Graphics/Interfaces/gsn_coordinates.shtml>*(wks,contour,variable,mkres)
>>>
>>>
>>> [6]
>>>
>>> The plots alternate between *cnFillMode*
>>> <http://www.ncl.ucar.edu/Document/Graphics/Resources/cn.shtml#cnFillMode>
>>> using the default  cnFillMode="AreaFill" and cnFillMode="RasterFill"
>>>
>>> In this case, I suggest cnFillMode="RasterFill"
>>>
>>> [7] For values that span 0.0, color palettes with *White-in-the-middle*
>>> <http://www.ncl.ucar.edu/Document/Graphics/color_table_gallery.shtml>
>>> work best
>>> ======
>>>
>>> *%> ncl*  MMali.ncl
>>>
>>> =====
>>>
>>> Good luck
>>>
>>>
>>> On Thu, Apr 4, 2019 at 10:06 AM Toni Klemm <toni-klemm at tamu.edu> wrote:
>>>
>>>> Hi Ali,
>>>>
>>>> I had this problem before. Since you extracted lat and lon data from
>>>> ASCII, it might be that your data doesn’t have metadata information
>>>> attached that tells NCL what it is (i.e., latitudes and longitudes).
>>>> Without that it is just a bunch of numbers for NCL. You can add this
>>>> metadata by adding this to your code after you extract your latitude and
>>>> longitude variables:
>>>>
>>>>   latitude!0 = "lat"
>>>>   latitude&lat = lat
>>>>   latitude at long_name = "latitude"
>>>>   latitude at units = "degrees_north"
>>>>
>>>>   longitude!0 = "lon"
>>>>   longitude&lon = lon
>>>>   longitude at long_name = "longitude"
>>>>   longitude at units = "degrees_east"
>>>>
>>>> Hope that helps,
>>>> Toni
>>>>
>>>>
>>>>
>>>> *Toni Klemm, Ph.D.*Postdoctoral Research Associate
>>>> Department of Ecosystem Science and Management
>>>> College of Agriculture and Life Sciences
>>>> Texas A&M University, College Station, TX
>>>> Contributor to the Early Career Climate Forum <http://www.eccforum.org>
>>>> www.toni-klemm.de | @toniklemm <http://twitter.com/toniklemm>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Apr 4, 2019, at 2:00 AM, MM Ali <mmali110 at gmail.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> I modified the ce_3.ncl code to read the ascii data. Data and the
>>>> modified ncl code are attached. The variables in the data are dummy,
>>>> latitude, longitude, variable, dummy2. I get the following errors
>>>>
>>>> (0)     check_for_y_lat_coord: Warning: Data either does not contain
>>>> (0)     a valid latitude coordinate array or doesn't contain one at all.
>>>> (0)     A valid latitude coordinate array should have a 'units'
>>>> (0)     attribute equal to one of the following values:
>>>> (0)         'degrees_north' 'degrees-north' 'degree_north' 'degrees
>>>> north' 'degrees_N' 'Degrees_north' 'degree_N' 'degreeN' 'degreesN' 'deg
>>>> north'
>>>> (0)     check_for_lon_coord: Warning: Data either does not contain
>>>> (0)     a valid longitude coordinate array or doesn't contain one at
>>>> all.
>>>> (0)     A valid longitude coordinate array should have a 'units'
>>>> (0)     attribute equal to one of the following values:
>>>> (0)         'degrees_east' 'degrees-east' 'degree_east' 'degrees east'
>>>> 'degrees_E' 'Degrees_east' 'degree_E' 'degreeE' 'degreesE' 'deg east'
>>>> (0)     Error: scalar_field: If the input data is 1-dimensional, you
>>>> must set sfXArray and sfYArray to 1-dimensional arrays of the same length.
>>>> warning:create: Bad HLU id passed to create, ignoring it
>>>>
>>>> Please help. It would be great if the necessary corrections are made to
>>>> the code (I am just a few days old for NCL, though 66+ years old!)
>>>> Thanks
>>>> Ali
>>>> *Dr. MM Ali*
>>>> Formerly:
>>>> Scientist G & Group Director
>>>> NRSC/ISRO
>>>> email: mmali110 at gmail.com
>>>>            mmali at coaps.fsu.edu
>>>> Mob: +91 9949045110
>>>> <may.txt><ce3.ncl>_______________________________________________
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>>>
>>
>> --
>> *Dr. MM Ali*
>> Formerly:
>> Scientist G & Group Director
>> NRSC/ISRO
>> email: mmali110 at gmail.com
>>            mmali at coaps.fsu.edu
>> Mob: +91 9949045110
>>
>
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