"""Generate random scores.
"""
import os
import logging
import numpy
import click
from click.types import FLOAT
from bob.extension.scripts.click_helper import verbosity_option
from bob.core import random
from bob.io.base import create_directories_safe
logger = logging.getLogger(__name__)
NUM_NEG = 5000
NUM_POS = 5000
[docs]def gen_score_distr(mean_neg, mean_pos, sigma_neg=1, sigma_pos=1):
"""Generate scores from normal distributions
Parameters
----------
mean_neg : float
Mean for negative scores
mean_pos : float
Mean for positive scores
sigma_neg : float
STDev for negative scores
sigma_pos : float
STDev for positive scores
Returns
-------
neg_scores : :any:`list`
Negatives scores
pos_scores : :any:`list`
Positive scores
"""
mt = random.mt19937() # initialise the random number generator
neg_generator = random.normal(numpy.float32, mean_neg, sigma_neg)
pos_generator = random.normal(numpy.float32, mean_pos, sigma_pos)
neg_scores = [neg_generator(mt) for _ in range(NUM_NEG)]
pos_scores = [pos_generator(mt) for _ in range(NUM_NEG)]
return neg_scores, pos_scores
[docs]def write_scores_to_file(neg, pos, filename):
"""Writes score distributions into 2-column score files. For the format of
the 2-column score files, please refer to Bob's documentation. See
:py:func:`bob.measure.load.split`.
Parameters
----------
neg : :py:class:`numpy.ndarray`
Scores for negative samples.
pos : :py:class:`numpy.ndarray`
Scores for positive samples.
filename : str
The path to write the score to.
"""
create_directories_safe(os.path.dirname(filename))
mt = random.mt19937()
nan_dist = random.uniform(numpy.float32, 0, 1)
with open(filename, 'wt') as f:
for i in pos:
text = '1 %f\n' % i if nan_dist(mt) > 0.01 else '1 nan\n'
f.write(text)
for i in neg:
text = '-1 %f\n' % i if nan_dist(mt) > 0.01 else '1 nan\n'
f.write(text)
@click.command()
@click.argument('outdir')
@click.option('--mean-neg', default=-1, type=FLOAT, show_default=True)
@click.option('--mean-pos', default=1, type=FLOAT, show_default=True)
@verbosity_option()
def gen(outdir, mean_neg, mean_pos, **kwargs):
"""Generate random scores.
Generates random scores for negative and positive scores, whatever they
could be. The
scores are generated using Gaussian distribution whose mean is an input
parameter. The generated scores can be used as hypothetical datasets.
"""
# Generate the data
neg_dev, pos_dev = gen_score_distr(mean_neg, mean_pos)
neg_eval, pos_eval = gen_score_distr(mean_neg, mean_pos)
# Write the data into files
write_scores_to_file(neg_dev, pos_dev,
os.path.join(outdir, 'scores-dev'))
write_scores_to_file(neg_eval, pos_eval,
os.path.join(outdir, 'scores-eval'))