Test of binary IO using netCDF in python against text IO.

test.py

# coding=utf-8

"""
Little example using netfdf-python to store Monte Carlo time-series data.
"""

from netCDF4 import Dataset
from numpy.random import uniform
from numpy.lib.npyio import savetxt


def create_test(name, zlib=False):
    """
    Creates a test netCDF file called `name`
    """
    test = Dataset(name, 'w')
    test.createDimension('seed', None)
    test.createDimension('mcs', None)
    test.createDimension('temp', None)

    test.createVariable('seed', 'i8', ('seed', ))
    test.createVariable('temp', 'f8', ('temp', ))
    ene = test.createVariable(
       'ene', 'f8',
       ('seed', 'temp', 'mcs', ),
       zlib=zlib)
    mag = test.createVariable(
        'mag', 'f8',
        ('seed', 'temp', 'mcs', ),
        zlib=zlib)

    for seed in range(10):
        for temp in range(100):
            ene[seed, temp, 0:100000] = uniform(100000)
            mag[seed, temp, 0:100000] = uniform(100000)

    test.close()


def create_text(name):
    """
    Creates a file containing severa milion of data in text format.
    """
    ftext = open(name, 'w')
    for seed in range(10):
        for temp in range(100):
            ftext.write(str(seed))
            ftext.write(str(temp))
            mag = uniform(size=(1, 100000))
            ene = uniform(size=(1, 100000))
            savetxt(ftext, mag)
            savetxt(ftext, ene)
    ftext.close()


def main():
    """
    Creates a test.nc file and a test_zlib.nc file just to try out netcdf.
    """
    from time import time
    
    start = time()
    create_test('test.nc')
    create_test('test_zlib.nc', zlib=True)
    end = time()
    print "Elapsed time 2 binary io: ", end - start

    start = time()
    create_text('test.txt')
    end = time()
    print "Elapsed time 1 text io: ", end - start


if __name__ == '__main__':
    main()