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
|
# benchmark reads and writes, with and without compression.
# tests all four supported file formats.
from typing import TYPE_CHECKING, Any
from numpy.random.mtrand import uniform
import netCDF4
from timeit import Timer
import os, sys
if TYPE_CHECKING:
from netCDF4 import Format as NCFormat
else:
NCFormat = Any
# create an n1dim by n2dim by n3dim random array.
n1dim = 30
n2dim = 15
n3dim = 73
n4dim = 144
ntrials = 10
sys.stdout.write('reading and writing a %s by %s by %s by %s random array ..\n'%(n1dim,n2dim,n3dim,n4dim))
array = uniform(size=(n1dim,n2dim,n3dim,n4dim))
def write_netcdf(filename,zlib=False,least_significant_digit=None,format: NCFormat='NETCDF4'):
file = netCDF4.Dataset(filename,'w',format=format)
file.createDimension('n1', n1dim)
file.createDimension('n2', n2dim)
file.createDimension('n3', n3dim)
file.createDimension('n4', n4dim)
foo = file.createVariable('data', 'f8',('n1','n2','n3','n4'),zlib=zlib,least_significant_digit=least_significant_digit)
foo[:] = array
file.close()
def read_netcdf(filename):
file = netCDF4.Dataset(filename)
data = file.variables['data'][:]
file.close()
for format in ['NETCDF3_CLASSIC','NETCDF3_64BIT','NETCDF4_CLASSIC','NETCDF4']:
sys.stdout.write('testing file format %s ...\n' % format)
# writing, no compression.
t = Timer("write_netcdf('test1.nc',format='%s')" % format,"from __main__ import write_netcdf")
sys.stdout.write('writing took %s seconds\n' %\
repr(sum(t.repeat(ntrials,1))/ntrials))
# test reading.
t = Timer("read_netcdf('test1.nc')","from __main__ import read_netcdf")
sys.stdout.write('reading took %s seconds\n' %
repr(sum(t.repeat(ntrials,1))/ntrials))
|
