def test_cash():
import sherpa.stats as ss
sherpa_stat = ss.Cash()
data, model, staterror, off_vec = get_test_data()
desired, fvec = sherpa_stat.calc_stat(data, model, staterror=staterror)
statsvec = gammapy_stats.cash(n_on=data, mu_on=model)
actual = np.sum(statsvec)
assert_allclose(actual, desired)
def test_cash(test_data):
import sherpa.stats as ss
sherpa_stat = ss.Cash()
data = test_data['n_on']
model = test_data['mu_sig']
staterror = test_data['staterror']
off_vec = test_data['n_off']
desired, fvec = sherpa_stat.calc_stat(data, model, staterror=staterror)
statsvec = stats.cash(n_on=data, mu_on=model)
actual = np.sum(statsvec)
assert_allclose(actual, desired)
def test_case(args):
import sherpa.stats as ss
mu_sig = float(args[1])
n_on = float(args[2])
n_off = float(args[3])
alpha = float(args[4])
model, data = get_data(mu_sig, n_on, n_off, alpha)
wstat, cash, cstat = ss.WStat(), ss.Cash(), ss.CStat()
print('wstat: {}'.format(wstat.calc_stat(model=model, data=data)[0]))
print('cash: {}'.format(cash.calc_stat(model=model, data=data)[0]))
print('cstat: {}'.format(cstat.calc_stat(model=model, data=data)[0]))
def statistic(self, stat):
"""Set Statistic to be used in the fit
Parameters
----------
stat : `~sherpa.stats.Stat`, str
Statistic
"""
import sherpa.stats as s
if isinstance(stat, six.string_types):
if stat == 'cash':
stat = s.Cash()
elif stat == 'wstat':
stat = s.WStat()
else:
raise ValueError("Undefined stat string: {}".format(stat))
if not isinstance(stat, s.Stat):
raise ValueError("Only sherpa statistics are supported")
self._stat = stat
# The pytest.param calls seem to get recorded as 2 xfails; I think
# this is for the error and because of warning messages, but it is not
# clear.
#
@requires_data
@requires_fits
@pytest.mark.parametrize("stat",
[None,
stats.Chi2(),
stats.Chi2ConstVar(),
stats.Chi2DataVar(),
stats.Chi2Gehrels(),
stats.Chi2ModVar(),
stats.Chi2XspecVar(),
stats.LeastSq(),
stats.Cash(),
stats.CStat(),
stats.WStat()])
def test_astro_data_plot_with_stat_simple(make_data_path, stat):
from sherpa.astro import io
infile = make_data_path('3c273.pi')
pha = io.read_pha(infile)
# tweak the data set so that we aren't using the default
# options (it shouldn't matter for this test but just
# in case).
#
# Note that background subtraction would normally be an issue
# for some of the stats (e.g. WStat), but this shouldn't