Re: transform a projection into regular lat-lon

I have successfully made the interpolation. Thanks to all for your kindly help! Best regards, Mark ________________________________ From: Dennis Shea <shea_at_ucar.edu> To: Mark Chan <cym263_at_yahoo.com> Cc: "ncl-talk_at_ucar.edu" <ncl-talk_at_ucar.edu> Sent: Thursday, March 1, 2012 4:57 PM Subject: Re: transform a projection into regular lat-lon You must interpolate the data. On 3/1/12 3:28 AM, Mark Chan wrote: > Dear Dave, > > Thanks so much. What you did is so helpful and I don't know how to > express my gratitude! > I feel embarrassed to ask the further question: How is it possible to > output an new data file with spatial grids as "0.1/0.1" lat-lon degree > for the domain as below. > > res_at_mpMinLatF = 46 ; Austria limits > res_at_mpMaxLatF = 50 > res_at_mpMinLonF = 9 > res_at_mpMaxLonF = 18 > > I want to extract the data of a specific area for other application. > > With my best regards, > Mark > > > ------------------------------------------------------------------------ > *From:* David Brown <dbrown_at_ucar.edu> > *To:* Mark Chan <cym263_at_yahoo.com> > *Cc:* NCL Helpline <ncl-talk_at_ucar.edu> > *Sent:* Wednesday, February 29, 2012 11:49 PM > *Subject:* Re: [ncl-talk] transform a projection into regular lat-lon > > Hi Mark, > After playing around with your data file for awhile I think I figured > out the correct settings for NCL to generate a native plot. > Given the rotated pole attributes you have below NCL needs the following > settings: > > res_at_mpCenterLonF = -162 + 180. > res_at_mpCenterLatF = 90 - 39.25 > > I am not familiar with this method of specifying the rotation but it > seems to produce the correct results. I am attaching a png file and a > script that draws the data both in the native projection and a different > arbitrary projection. > -dave > > > On Feb 29, 2012, at 2:55 AM, Mark Chan wrote: > >> Dear David, >> >> I still have problem for plot. The original data is very large and I >> made the annual average (by using CDO) for making the file smaller, as >> the attached file. >> The original file has rotated info as in the below, but the >> CDO-processed file doesn't have this info. Could you please help have >> a look at the data and give a plot suggestion? >> >> Thanks so much! >> Mark >> >> >> char rotated_pole ; >> rotated_pole:long_name = "coordinates of the rotated North Pole" ; >> rotated_pole:grid_mapping_name = "rotated_latitude_longitude" ; >> rotated_pole:grid_north_pole_latitude = 39.25f ; >> rotated_pole:grid_north_pole_longitude = -162.f ; >> >> >> ------------------------------------------------------------------------ >> *From:* David Brown <dbrown_at_ucar.edu <mailto:dbrown_at_ucar.edu>> >> *To:* Mark Chan <cym263_at_yahoo.com <mailto:cym263_at_yahoo.com>> >> *Cc:* NCL Helpline <ncl-talk_at_ucar.edu <mailto:ncl-talk_at_ucar.edu>> >> *Sent:* Tuesday, February 28, 2012 6:18 PM >> *Subject:* Re: [ncl-talk] transform a projection into regular lat-lon >> >> Hi Mark, >> Since the NCL is looking for the center longitude and you have the >> north pole, I think you should try setting mpCenterLatF to 39.25 - 90. >> Let us know if that does not produce a reasonable plot. >> -dave >> >> >> On Feb 28, 2012, at 6:11 AM, Mark Chan wrote: >> >>> Dear Dennis, >>> >>> Thanks a lot for your message. I wonder whether I could find the >>> input data for the example in the website, so I could compare it with >>> my data. >>> For instance, how could I get the parameters as in the below since my >>> data has something like "grid_north_pole_latitude : 39.25". >>> >>>  res_at_mpCenterLonF          = lon2d_at_Longitude_of_southern_pole >>>    res_at_mpCenterLatF          = lon2d_at_Latitude_of_southern_pole + 90 >>> Thanks a lot again! >>> >>> Mark >>> ------------------------------------------------------------------------ >>> *From:* Dennis Shea <shea_at_ucar.edu <mailto:shea_at_ucar.edu>> >>> *To:* Mark Chan <cym263_at_yahoo.com <mailto:cym263_at_yahoo.com>> >>> *Cc:* "ncl-talk_at_ucar.edu <mailto:ncl-talk_at_ucar.edu>" >>> <ncl-talk_at_ucar.edu <mailto:ncl-talk_at_ucar.edu>> >>> *Sent:* Monday, February 27, 2012 5:39 PM >>> *Subject:* Re: [ncl-talk] transform a projection into regular lat-lon >>> >>> Does >>> http://www.ncl.ucar.edu/Applications/rotatedltln.shtml >>> answer your question. Please read the text. >>> >>> Good Luck >>> >>> On 2/27/12 3:31 AM, Mark Chan wrote: >>> > Dear NCL users, >>> > >>> > I have a model output file having info as in the below. I was told >>> it is >>> > "rotated projection" (I don't know exactly what it is). >>> > Could any one help give me a suggestion how to transform this data into >>> > regular lat-lon projection? The main issue is how to define its >>> > projection when reading it with NCL? >>> > >>> > Thanks so much in advance! >>> > Mark Chan >>> > >>> > ----------------------Data file info ------------------------ >>> > dimensions: >>> > ncl_scalar = 1 >>> > rlat = 92 >>> > rlon = 108 >>> > time = 87648 // unlimited >>> > height_2m = 1 >>> > variables: >>> > double time ( time ) >>> > standard_name : time >>> > units : seconds since 1989-01-01 00:00:00 >>> > calendar : standard >>> > float rlon ( rlon ) >>> > standard_name : grid_longitude >>> > units : degrees >>> > float rlat ( rlat ) >>> > standard_name : grid_latitude >>> > units : degrees >>> > float lon ( rlat, rlon ) >>> > standard_name : longitude >>> > units : degrees_east >>> > float lat ( rlat, rlon ) >>> > standard_name : latitude >>> > units : degrees_north >>> > float height_2m ( height_2m ) >>> > long_name : height above surface >>> > units : m >>> > character rotated_pole ( ncl_scalar ) >>> > long_name : coordinates of the rotated North Pole >>> > grid_mapping_name : rotated_latitude_longitude >>> > grid_north_pole_latitude : 39.25 >>> > grid_north_pole_longitude : -162 >>> > short tas ( time, height_2m, rlat, rlon ) >>> > standard_name : air_temperature >>> > long_name : 2m temperature >>> > units : K >>> > coordinates : lon lat >>> > scale_factor : 0.004940663 >>> > add_offset : 161.8932 >>> > ==================================== >>> > >>> > -----------------Its grids info is >>> > as----------------------------------------------------- >>> > rlon = -10.445, -10.335, -10.225, -10.115, -10.005, -9.895, -9.785, >>> -9.675, >>> > -9.565, -9.455, -9.345, -9.235, -9.125, -9.015, -8.905, -8.795, -8.685, >>> > -8.575, -8.465, -8.355, -8.245, -8.135, -8.025, -7.915, -7.805, -7.695, >>> > -7.585, -7.475, -7.365, -7.255, -7.145, -7.035, -6.925, -6.815, -6.705, >>> > -6.595, -6.485, -6.375, -6.265, -6.155, -6.045, -5.935, -5.825, -5.715, >>> > -5.605, -5.495, -5.385, -5.275, -5.165, -5.055, -4.945, -4.835, -4.725, >>> > -4.615, -4.505, -4.395, -4.285, -4.175, -4.065, -3.955, -3.845, -3.735, >>> > -3.625, -3.515, -3.405, -3.295, -3.185, -3.075, -2.965, -2.855, -2.745, >>> > -2.635, -2.525, -2.415, -2.305, -2.195, -2.085, -1.975, -1.865, -1.755, >>> > -1.645, -1.535, -1.425, -1.315, -1.205, -1.095, -0.985, -0.875, -0.765, >>> > -0.655, -0.545, -0.435, -0.325, -0.215, -0.105, 0.005, 0.115, 0.225, >>> > 0.335, 0.445, 0.555, 0.665, 0.775, 0.885, 0.995, 1.105, 1.215, 1.325 ; >>> > >>> > rlat = -8.855, -8.745, -8.635, -8.525, -8.415, -8.305, -8.195, -8.085, >>> > -7.975, -7.865, -7.755, -7.645, -7.535, -7.425, -7.315, -7.205, -7.095, >>> > -6.985, -6.875, -6.765, -6.655, -6.545, -6.435, -6.325, -6.215, -6.105, >>> > -5.995, -5.885, -5.775, -5.665, -5.555, -5.445, -5.335, -5.225, -5.115, >>> > -5.005, -4.895, -4.785, -4.675, -4.565, -4.455, -4.345, -4.235, -4.125, >>> > -4.015, -3.905, -3.795, -3.685, -3.575, -3.465, -3.355, -3.245, -3.135, >>> > -3.025, -2.915, -2.805, -2.695, -2.585, -2.475, -2.365, -2.255, -2.145, >>> > -2.035, -1.925, -1.815, -1.705, -1.595, -1.485, -1.375, -1.265, -1.155, >>> > -1.045, -0.935, -0.825, -0.715, -0.605, -0.495, -0.385, -0.275, -0.165, >>> > -0.055, 0.055, 0.165, 0.275, 0.385, 0.495, 0.605, 0.715, 0.825, 0.935, >>> > 1.045, 1.155 ; >>> > >>> > >>> > >>> > >>> > _______________________________________________ >>> > ncl-talk mailing list >>> > List instructions, subscriber options, unsubscribe: >>> > http://mailman.ucar.edu/mailman/listinfo/ncl-talk >>> >>> >>> _______________________________________________ >>> ncl-talk mailing list >>> List instructions, subscriber options, unsubscribe: >>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk >> >> >> >> <Rotated_2009.nc> > > > > > > _______________________________________________ > ncl-talk mailing list > List instructions, subscriber options, unsubscribe: > http://mailman.ucar.edu/mailman/listinfo/ncl-talk

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Received on Fri Mar 2 01:29:11 2012