Re: [Matplotlib-users] Data plotting in a wrong place

[Benjamin R. <ben...@ou...>]

don't know if this would make a difference, but meshgrid here is completely
unnecessary given that the netcdf file has the lats and lons in 2
dimensions anyway.

Given that this is a polar projection, I wouldn't be surprised if there is
something wonky there. Are the longitudes and latitudes monotonic?

Cheers!
Ben Root


On Thu, Jun 26, 2014 at 4:42 AM, billyi <bil...@ho...> wrote:

> Hi all! I'm trying to plot some sea ice freeboard data (netCDF, Gridded
> total
> freeboard) on the Antarctic sea, but the data that should plot nicely
> around
> Antarctica lies at the bottom of my image. NetCDF and matplotlib are fairly
> new to me so I'm not quite sure, where the error could be and I feel like
> I've search and tried everything there is.
> <http://matplotlib.1069221.n5.nabble.com/file/n43580/bad_fb.png>
>
> from scipy.io.netcdf import netcdf_file as Dataset
> import numpy as np
> import matplotlib.pyplot as plt
>
> FB = Dataset('./datasets/fb-0217-0320.nc', 'r')
> f = FB.variables['f'][:,:]
> lat = FB.variables['lat'][:,0]
> lon = FB.variables['lon'][0,:]
> masked_fb = np.ma.masked_where(np.isnan(f), f)
> mtx_lon, mtx_lat = np.meshgrid(lon, lat)
> m = Basemap(projection='spstere',boundinglat=-50, lon_0=180.,
> resolution='l')
> m.bluemarble()
>
> plt.figure()
> m.pcolormesh(mtx_lon, mtx_lat, masked_fb, latlon=True)
> plt.show()
>
> And ncdump gives:
> dimensions:
> x = 79 ;
> y = 83 ;
> variables:
> float lat(y, x) ;
>     lat:standard_name = "latitude" ;
>     lat:long_name = "latitude coordinate" ;
>     lat:units = "degrees_north" ;
> float lon(y, x) ;
>     lon:standard_name = "longitude" ;
>     lon:long_name = "longitude coordinate" ;
>     lon:units = "degrees_east" ;
> float f(y, x) ;
>     f:long_name = "total_freeboard" ;
>     f:units = "mm" ;
>     f:coordinates = "lat lon" ;
>
> Could there be something funny with the projection or handling the data?
> (When using meshgrid, handling the coordinates like ['lat'][:,0] seems
> necessary, otherwise it turns lats and lons like (6557,6557) and gives
> error
> message for pcolormesh, since masked_fb is (83,79).)
>
>
>
> --
> View this message in context:
> http://matplotlib.1069221.n5.nabble.com/Data-plotting-in-a-wrong-place-tp43580.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
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