Source code for openquake.commands.reduce

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright (C) 2015-2017 GEM Foundation
#
# OpenQuake is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# OpenQuake is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with OpenQuake. If not, see <http://www.gnu.org/licenses/>.

from __future__ import print_function
import random
import shutil
from openquake.hazardlib import valid, nrml
from openquake.baselib.python3compat import encode
from openquake.baselib import sap


[docs]def random_filter(objects, reduction_factor, seed=42): """ Given a list of objects, returns a sublist by extracting randomly some elements. The reduction factor (< 1) tells how small is the extracted list compared to the original list. """ assert 0 < reduction_factor <= 1, reduction_factor rnd = random.Random(seed) out = [] for obj in objects: if rnd.random() <= reduction_factor: out.append(obj) return out
@sap.Script def reduce(fname, reduction_factor): """ Produce a submodel from `fname` by sampling the nodes randomly. Supports source models, site models and exposure models. As a special case, it is also able to reduce .csv files by sampling the lines. This is a debugging utility to reduce large computations to small ones. """ if fname.endswith('.csv'): with open(fname) as f: all_lines = f.readlines() lines = random_filter(all_lines, reduction_factor) shutil.copy(fname, fname + '.bak') print('Copied the original file in %s.bak' % fname) with open(fname, 'wb') as f: for line in lines: f.write(encode(line)) print('Extracted %d lines out of %d' % (len(lines), len(all_lines))) return node = nrml.read(fname) model = node[0] if model.tag.endswith('exposureModel'): total = len(model.assets) model.assets.nodes = random_filter(model.assets, reduction_factor) num_nodes = len(model.assets) elif model.tag.endswith('siteModel'): total = len(model) model.nodes = random_filter(model, reduction_factor) num_nodes = len(model) elif model.tag.endswith('sourceModel'): total = len(model) model.nodes = random_filter(model, reduction_factor) num_nodes = len(model) else: raise RuntimeError('Unknown model tag: %s' % model.tag) shutil.copy(fname, fname + '.bak') print('Copied the original file in %s.bak' % fname) with open(fname, 'wb') as f: nrml.write([model], f, xmlns=node['xmlns']) print('Extracted %d nodes out of %d' % (num_nodes, total)) reduce.arg('fname', 'path to the model file') reduce.arg('reduction_factor', 'reduction factor in the range 0..1', type=valid.probability)