2025-09-05 09:42:21 +02:00

209 lines
6.7 KiB
Python
Executable File

from netCDF4 import Dataset
from argparse import ArgumentParser
import numpy as np
import sys
#
# Basic iceberg trajectory post-processing python script.
# This script collates iceberg trajectories from the distributed datasets written
# out by each processing region and rearranges the ragged arrays into contiguous
# streams for each unique iceberg. The output arrays are 2D (ntraj, ntimes) arrays.
# Note that some icebergs may only exist for a subset of the possible times. In these
# cases the missing instances are filled with invalid (NaN) values.
#
# Version 2.0 August 2017. Adapted to process all variables and retain original
# datatypes. (acc@noc.ac.uk)
parser = ArgumentParser(description='produce collated trajectory file \
from distributed output files, e.g. \
\n python ./icb_pp.py \
-t trajectory_icebergs_004248_ \
-n 296 -o trajsout.nc' )
parser.add_argument('-t',dest='froot',
help='fileroot_of_distrbuted_data; root name \
of distributed trajectory output (usually \
completed with XXXX.nc, where XXXX is the \
4 digit processor number)',
default='trajectory_icebergs_004248_')
parser.add_argument('-n',dest='fnum',help='number of distributed files to process',
type=int, default=None)
parser.add_argument('-o',dest='fout',
help='collated_output_file; file name to receive \
the collated trajectory data', default='trajsout.nc')
args = parser.parse_args()
default_used = 0
if args.froot is None:
pathstart = 'trajectory_icebergs_004248_'
default_used = 1
else:
pathstart = args.froot
if args.fnum is None:
procnum = 0
default_used = 1
else:
procnum = args.fnum
if args.fout is None:
pathout = 'trajsout.nc'
default_used = 1
else:
pathout = args.fout
if default_used == 1:
print('At least one default value will be used; command executing is:')
print('icb_pp.py -t ',pathstart,' -n ',procnum,' -o ',pathout)
if procnum < 1:
print('Need some files to collate! procnum = ',procnum)
sys.exit(11)
icu = []
times = []
#
# Loop through all distributed datasets to obtain the complete list
# of iceberg identification numbers and timesteps
#
for n in range(procnum):
nn = '%4.4d' % n
fw = Dataset(pathstart+nn+'.nc')
# keep a list of the variables in the first dataset
if n == 0:
varlist = fw.variables
#
# skip any files with no icebergs
if len(fw.dimensions['n']) > 0:
print pathstart+nn+'.nc'
ic = fw.variables['iceberg_number'][:,0]
ts = fw.variables['timestep'][:]
icv = np.unique(ic)
ts = np.unique(ts)
print('Min Max ts: ',ts.min(), ts.max())
print('Number unique icebergs= ',icv.shape[0])
icu.append(icv)
times.append(ts)
fw.close()
#
# Now flatten the lists and reduce to the unique spanning set
#
try:
icu = np.concatenate(icu)
except ValueError:
# No icebergs: create an empty output file.
print 'No icebergs in the model.'
fw = Dataset(pathstart+'0000.nc')
fo = Dataset(pathout, 'w', format='NETCDF4_CLASSIC')
ntrj = fo.createDimension('ntraj', None)
icbn = fo.createVariable('iceberg_number', 'i4',('ntraj'))
n = 0
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
print 'key is ',key
oout = fo.createVariable(key, value.dtype, ('ntraj'),
zlib=True, complevel=1)
oout.long_name = fw.variables[key].getncattr('long_name')
oout.units = fw.variables[key].getncattr('units')
n = n + 1
fw.close()
fo.close()
sys.exit()
icu = np.unique(icu)
times = np.concatenate(times)
times = np.unique(times)
ntraj = icu.shape[0]
print(ntraj, ' unique icebergs found across all datasets')
print('Icebergs ids range from: ',icu.min(), 'to: ',icu.max())
print('times range from: ',times.min(), 'to: ', times.max())
#
# Declare array to receive data from all files
#
nt = times.shape[0]
#
n=0
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
n = n + 1
inarr = np.zeros((n, ntraj, nt))
#
# initially fill with invalid data
#
inarr.fill(np.nan)
#
# Declare some lists to store variable names, types and long_name and units attributes
# iceberg_number gets special treatment
innam = []
intyp = []
inlngnam = []
inunits = []
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
innam.append(key)
#
# reopen the first datset to collect variable attributes
# (long_name and units only)
#
nn = '%4.4d' % 0
fw = Dataset(pathstart+nn+'.nc')
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
intyp.append(fw.variables[key].dtype)
inlngnam.append(fw.variables[key].getncattr('long_name'))
inunits.append(fw.variables[key].getncattr('units'))
fw.close()
#
# loop through distributed datasets again, this time
# checking indices against icu and times lists and
# inserting data into the correct locations in the
# collated sets.
#
for n in range(procnum):
nn = '%4.4d' % n
fw = Dataset(pathstart+nn+'.nc')
#
# Note many distributed datafiles will contain no iceberg data
# so skip quickly over these
m = len(fw.dimensions['n'])
if m > 0:
inx = np.zeros(m, dtype=int)
tsx = np.zeros(m, dtype=int)
#print pathstart+nn+'.nc'
ic = fw.variables['iceberg_number'][:,0]
ts = fw.variables['timestep'][:]
for k in range(m):
inxx = np.where(icu == ic[k])
inx[k] = inxx[0]
for k in range(m):
inxx = np.where(times == ts[k])
tsx[k] = inxx[0]
n = 0
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
insmall = fw.variables[innam[n]][:]
inarr[n,inx[:],tsx[:]] = insmall[:]
n = n + 1
fw.close()
#
# Finally create the output file and write out the collated sets
#
fo = Dataset(pathout, 'w', format='NETCDF4_CLASSIC')
ntrj = fo.createDimension('ntraj', ntraj)
nti = fo.createDimension('ntime', None)
icbn = fo.createVariable('iceberg_number', 'i4',('ntraj'))
icbn[:] = icu
n = 0
for key, value in varlist.iteritems() :
if key != "iceberg_number" :
oout = fo.createVariable(innam[n], intyp[n], ('ntraj','ntime'),
zlib=True, complevel=1, chunksizes=(1,nt))
oout[:,:] = inarr[n,:,:]
oout.long_name = inlngnam[n]
oout.units = inunits[n]
n = n + 1
fo.close()