[Matplotlib-users] plotting netcdf data on a map in matplotlib

Thu Mar 30 16:16:49 EDT 2017

I am trying to plot data from a netcdf file onto a map through matplotlib.
I initially tried to use basemap but then someone suggested that I use
cartopy based on the website:

http://scitools.org.uk/cartopy.

Either way I am able to generate the map fine but am having difficulty
plotting the data successfully.  For instance using basemap I wind up
getting a weird plot of data that does not make sense.  Also how to I go
about plotting the netcdf data around the dateline?  Attached is the ncdump
output (gridoutput.txt) for the netcdf file in terms of the grid and also
the script that I am using to try to plot the data (netcdfplot.py).
Can anyone give me some suggestions on how to go about fixing the errors
that I have in the script?

-Jason
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netcdf \2017032800 {
dimensions:
	latitude = 159 ;
	longitude = 361 ;
	time = UNLIMITED ; // (1 currently)
variables:
	double latitude(latitude) ;
		latitude:units = "degrees_north" ;
		latitude:long_name = "latitude" ;
	double longitude(longitude) ;
		longitude:units = "degrees_east" ;
		longitude:long_name = "longitude" ;
	double time(time) ;
		time:units = "seconds since 1970-01-01 00:00:00.0 0:00" ;
		time:long_name = "verification time generated by wgrib2 function verftime()" ;
		time:reference_time = 1490659200. ;
		time:reference_time_type = 1 ;
		time:reference_date = "2017.03.28 00:00:00 UTC" ;
		time:reference_time_description = "analyses, reference date is fixed" ;
		time:time_step_setting = "auto" ;
		time:time_step = 0. ;
	float HTSGW_surface(time, latitude, longitude) ;
		HTSGW_surface:_FillValue = 9.999e+20f ;
		HTSGW_surface:short_name = "HTSGW_surface" ;
		HTSGW_surface:long_name = "Significant Height of Combined Wind Waves and Swell" ;
		HTSGW_surface:level = "surface" ;
		HTSGW_surface:units = "m" ;

// global attributes:
		:Conventions = "COARDS" ;
		:History = "created by wgrib2" ;
		:GRIB2_grid_template = 0 ;
data:

 latitude = -78, -77, -76, -75, -74, -73, -72, -71, -70, -69, -68, -67, -66, 
    -65, -64, -63, -62, -61, -60, -59, -58, -57, -56, -55, -54, -53, -52, 
    -51, -50, -49, -48, -47, -46, -45, -44, -43, -42, -41, -40, -39, -38, 
    -37, -36, -35, -34, -33, -32, -31, -30, -29, -28, -27, -26, -25, -24, 
    -23, -22, -21, -20, -19, -18, -17, -16, -15, -14, -13, -12, -11, -10, -9, 
    -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 
    13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 
    31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 
    49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 
    67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80 ;

 longitude = 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 
    193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 
    207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 
    221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 
    235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 
    249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 
    263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 
    277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 
    291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 
    305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 
    319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 
    333, 334, 335, 336, 337, 338, 339, 340, 341, 342, 343, 344, 345, 346, 
    347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359, 0, 1, 2, 
    3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
    23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 
    59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 
    77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 
    95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 
    110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 
    124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 
    138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 
    152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 
    166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180 ;

 time = 1490659200 ;
}
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