def compare_scipy_1d(self, kernel):
print("\n|Test_KDE_PDF:test_compare_scipy_1d()|")
NUM = 100
a1 = np.random.normal(6.0, 1.0, NUM // 2)
a2 = np.random.lognormal(0, 0.5, size=NUM // 2)
aa = np.concatenate([a1, a2])
bins = utils.spacing([-1, 14.0], 'lin', 40)
grid = utils.spacing(bins, 'lin', 3000)
methods = ['scott', 0.04, 0.2, 0.8]
classes = [
lambda xx, bw: sp.stats.gaussian_kde(xx, bw_method=bw),
lambda xx, bw: kale.KDE(xx, bandwidth=bw, kernel=kernel)
]
for mm in methods:
kde_list = []
for cc in classes:
try:
test = cc(aa, mm).density(grid, probability=True)[1]
except AttributeError:
test = cc(aa, mm).pdf(grid)
kde_list.append(test)
print("method: {}".format(mm))
print("\t" + utils.stats_str(kde_list[0]))
print("\t" + utils.stats_str(kde_list[1]))
assert_true(np.allclose(kde_list[0], kde_list[1]))
return
def ppf(self, cd):
"""Percentile Point Function - the inverse of the cumulative distribution function.
NOTE: for symmetric kernels, this (effectively) uses points only with cdf in [0.0, 0.5],
which produces better numerical results (unclear why).
"""
if self._ppf_func is None:
x0, y0 = self.cdf_grid
self._ppf_func = sp.interpolate.interp1d(
y0, x0, kind='cubic', fill_value='extrapolate') # **self._INTERP_KWARGS)
# Symmetry can be utilized to get better accuracy of results, see 'note' above
if self.SYMMETRIC:
cd = np.atleast_1d(cd)
idx = (cd > 0.5)
cd = np.copy(cd)
cd[idx] = 1 - cd[idx]
try:
xx = self._ppf_func(cd)
except ValueError:
logging.error("`_ppf_func` failed!")
logging.error("input `cd` = {} <=== {}".format(
utils.stats_str(cd), utils.array_str(cd)))
for vv in self.cdf_grid:
logging.error("\tcdf_grid: {} <== {}".format(
utils.stats_str(vv), utils.array_str(vv)))
raise
if self.SYMMETRIC:
xx[idx] = -xx[idx]
return xx
def test_resample_keep_params_1(self):
print("\n|Test_KDE_Resample:test_resample_keep_params_1()|")
np.random.seed(9235)
NUM = int(1e3)
# Construct some random data
# ------------------------------------
a1 = np.random.normal(6.0, 1.0, NUM // 2)
a2 = np.random.lognormal(1.0, 0.5, size=NUM // 2)
aa = np.concatenate([a1, a2])
# aa = a1
bb = np.random.normal(3.0, 0.02, aa.size) + aa / 100
data = [aa, bb]
norm = 2.3
# Add an array of uniform values at location `ii`, make sure they are preserved in resample
for ii in range(3):
test = np.array(data)
tt = norm * np.ones_like(test[0])
idx = np.random.choice(tt.size, tt.size // 2)
tt[idx] *= -1
test = np.insert(test, ii, tt, axis=0)
# Construct KDE
kde3d = kale.KDE(test)
# Resample from KDE preserving the uniform data
samples = kde3d.resample(NUM, keep=ii)
# Make sure the uniform values are still the same
param_samp = samples[ii]
assert_true(
np.all(
np.isclose(param_samp, norm)
| np.isclose(param_samp, -norm)))
# Make sure the other two parameters are consistent (KS-test) with input data
samples = np.delete(samples, ii, axis=0)
for jj in range(2):
stuff = [samples[jj], data[jj]]
ks, pv = sp.stats.ks_2samp(*stuff)
msg = "{} {} :: {:.2e} {:.2e}".format(ii, jj, ks, pv)
print("\t" + utils.stats_str(stuff[0]))
print("\t" + utils.stats_str(stuff[1]))
print(msg)
assert_true(pv > 0.05)
return
def _check_reflect(reflect, data, weights=None, helper=False):
"""Make sure the given `reflect` argument is valid given the data shape
"""
if reflect is None:
return reflect
if reflect is False:
return None
# NOTE: FIX: Should this happen in the method that calls `_check_reflect`?
# data = np.atleast_2d(data)
# ndim, nval = np.shape(data)
data = np.asarray(data)
ndim, nval = data.shape
if reflect is True:
reflect = [True for ii in range(ndim)]
if (len(reflect) == 2) and (ndim == 1):
reflect = np.atleast_2d(reflect)
if (len(reflect) != ndim): # and not ((len(reflect) == 2) and (ndim == 1)):
err = "`reflect` ({},) must match the data with shape ({}) parameters!".format(
len(reflect), data.shape)
raise ValueError(err)
try:
goods = [(ref is None) or (ref is True) or (len(ref) == 2) for ref in reflect]
except TypeError as err:
err = "Invalid `reflect` argument: Error: '{}'".format(err)
raise ValueError(err)
if not np.all(goods):
err = "each row of `reflect` must be `None` or have shape (2,)! '{}'".format(reflect)
raise ValueError(err)
# Perform additional diagnostics
for ii in range(ndim):
if (reflect[ii] is True):
reflect[ii] = [np.min(data[ii])*(1 - _NUM_PAD), np.max(data[ii])*(1 + _NUM_PAD)]
elif (reflect[ii] is not None) and (True in reflect[ii]):
if reflect[ii][0] is True:
reflect[ii][0] = np.min(data[ii])*(1 - _NUM_PAD)
if reflect[ii][1] is True:
reflect[ii][1] = np.max(data[ii])*(1 + _NUM_PAD)
if np.all(np.array(reflect[ii]) != None) and (reflect[ii][0] >= reflect[ii][1]): # noqa
err = "Reflect is out of order: `reflect`[{}] = {} !".format(ii, reflect[ii])
raise ValueError(err)
if helper:
# Warn if any datapoints are outside of reflection bounds
bads = utils.bound_indices(data[ii, :], reflect[ii], outside=True)
if np.any(bads):
if weights is None:
frac = np.count_nonzero(bads) / bads.size
else:
frac = np.sum(weights[bads]) / np.sum(weights)
msg = (
"A fraction {:.2e} of data[{}] ".format(frac, ii) +
" are outside of `reflect` bounds!"
)
logging.warning(msg)
msg = (
"`reflect[{}]` = {}; ".format(ii, reflect[ii]) +
"`data[{}]` = {}".format(ii, utils.stats_str(data[ii], weights=weights))
)
logging.warning(msg)
logging.warning("I hope you know what you're doing.")
return reflect
def _resample_reflect(self, data, size, reflect, weights=None, keep=None):
"""Resample the given data using reflection.
"""
matrix = self.matrix
# Modify covariance-matrix for any `keep` dimensions
matrix = utils.cov_keep_vars(matrix, keep, reflect=reflect)
ndim, nvals = np.shape(data)
# Actually 'reflect' (append new, mirrored points) around the given reflection points
# Also construct bounding box for valid data
data, bounds, weights = self._reflect_data(data, reflect, weights=weights)
# Remove data points outside of kernels (or truncated region)
data, weights = self._truncate_reflections(data, bounds, weights=weights)
if (self._chunk is not None) and (self._chunk < size):
num_chunks = int(np.ceil(size/self._chunk))
chunk_size = int(np.ceil(size/num_chunks))
else:
chunk_size = size
num_chunks = 1
# Draw randomly from the given data points, proportionally to their weights
samps = np.zeros((size, ndim))
num_good = 0
cnt = 0
MAX = 10
draw = chunk_size
fracs = []
while (num_good < size) and (cnt < MAX * num_chunks):
# Draw candidate resample points
# set `keep` to None, `matrix` is already modified to account for it
trial = self._resample_clear(data, draw, weights=weights, matrix=matrix, keep=None)
# Find the (boolean) indices of values within target boundaries
idx = utils.bound_indices(trial, bounds)
# Store good values to output array
ngd = np.count_nonzero(idx)
fracs.append(ngd/idx.size)
if num_good + ngd <= size:
samps[num_good:num_good+ngd, :] = trial.T[idx, :]
else:
ngd = (size - num_good)
samps[num_good:num_good+ngd, :] = trial.T[idx, :][:ngd]
# Increment counters
num_good += ngd
cnt += 1
# Next time, draw twice as many as we need
draw = np.minimum(size - num_good, chunk_size)
draw = (2**ndim) * draw
draw = np.minimum(draw, int(self._chunk))
if num_good < size:
err = "Failed to draw '{}' samples in {} iterations!".format(size, cnt)
logging.error("")
logging.error(err)
logging.error("fracs = {}\n\t{}".format(utils.stats_str(fracs), fracs))
logging.error("Obtained {} samples".format(num_good))
logging.error("Reflect: {}".format(reflect))
logging.error("Bandwidths: {}".format(np.sqrt(self.matrix.diagonal().squeeze())))
logging.error("data = ")
for dd in data:
logging.error("\t{}".format(utils.stats_str(dd)))
raise RuntimeError(err)
samps = samps.T
return samps
