Masked arrays in PyNIO 1.3.0b1

From: Daran L. Rife <drife_at_nyahnyahspammersnyahnyah>
Date: Sat, 30 Aug 2008 12:49:20 -0600 (MDT)


This didn't seem to get through last time round.

I Recently installed the latest version of PyNIO 1.3.0b1
for Mac OS X Leopard (Intel) running Python 2.5:


I was excited to learn that when reading variables from
netCDF files, Nio now returns a masked array for any var-
iable having the _FillValue or missing_value attribute
set within the input file.

When I try this, Nio still seems to return a numpy.ndarray,
instead of the desired masked array. Attached below is out-
put from my IDLE session. Could someone please help me un-
derstand what I am doing wrong?

Also, are there examples showing how to properly set the
new MaskedArrayMode options?

Thanks in advance for your help,


Python 2.5 (r25:51918, Sep 19 2006, 08:49:13)
Type "copyright", "credits" or "license" for more information.
IPython 0.8.4 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object'. ?object also works, ?? prints more.
In [1]: import Nio as nio
In [2]: f = nio.open_file('', 'r')
In [3]: sst = f.variables['sst_data']
In [4]: print sst
Variable: sst_data
Type: float
Total Size: 3110400 bytes
             777600 values
Number of Dimensions: 3
Dimensions and sizes:        [time | 1] x [latitude | 720] x [longitude | 1080]
             time: [14022..14022]
             latitude: [24.52084..54.47918]
             longitude: [-98.47916..-53.52083]
Number of Attributes: 5
          long_name :        MODIS 8-day composite SST
          standard_name :        sea_surface_temperature
          units :        degC
          valid_range :        [-1.979918837547302, 31.75502777099609] _FillValue : 
In [5]: s = sst.get_value()
In [6]: type(s)
Out[6]: <type 'numpy.ndarray'>
In [8]: from numpy import ma
In [9]: s = ma.masked_values(sst.get_value(), sst._FillValue) # Force   data into ma
In [10]: type(s)
Out[10]: <class ''>
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Received on Sat Aug 30 2008 - 12:49:20 MDT

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