Inzynierka/Lib/site-packages/scipy/signal/tests/test_peak_finding.py
2023-06-02 12:51:02 +02:00

888 lines
33 KiB
Python

import copy
import numpy as np
from numpy.testing import (
assert_,
assert_equal,
assert_allclose,
assert_array_equal
)
import pytest
from pytest import raises, warns
from scipy.signal._peak_finding import (
argrelmax,
argrelmin,
peak_prominences,
peak_widths,
_unpack_condition_args,
find_peaks,
find_peaks_cwt,
_identify_ridge_lines
)
from scipy.signal.windows import gaussian
from scipy.signal._peak_finding_utils import _local_maxima_1d, PeakPropertyWarning
def _gen_gaussians(center_locs, sigmas, total_length):
xdata = np.arange(0, total_length).astype(float)
out_data = np.zeros(total_length, dtype=float)
for ind, sigma in enumerate(sigmas):
tmp = (xdata - center_locs[ind]) / sigma
out_data += np.exp(-(tmp**2))
return out_data
def _gen_gaussians_even(sigmas, total_length):
num_peaks = len(sigmas)
delta = total_length / (num_peaks + 1)
center_locs = np.linspace(delta, total_length - delta, num=num_peaks).astype(int)
out_data = _gen_gaussians(center_locs, sigmas, total_length)
return out_data, center_locs
def _gen_ridge_line(start_locs, max_locs, length, distances, gaps):
"""
Generate coordinates for a ridge line.
Will be a series of coordinates, starting a start_loc (length 2).
The maximum distance between any adjacent columns will be
`max_distance`, the max distance between adjacent rows
will be `map_gap'.
`max_locs` should be the size of the intended matrix. The
ending coordinates are guaranteed to be less than `max_locs`,
although they may not approach `max_locs` at all.
"""
def keep_bounds(num, max_val):
out = max(num, 0)
out = min(out, max_val)
return out
gaps = copy.deepcopy(gaps)
distances = copy.deepcopy(distances)
locs = np.zeros([length, 2], dtype=int)
locs[0, :] = start_locs
total_length = max_locs[0] - start_locs[0] - sum(gaps)
if total_length < length:
raise ValueError('Cannot generate ridge line according to constraints')
dist_int = length / len(distances) - 1
gap_int = length / len(gaps) - 1
for ind in range(1, length):
nextcol = locs[ind - 1, 1]
nextrow = locs[ind - 1, 0] + 1
if (ind % dist_int == 0) and (len(distances) > 0):
nextcol += ((-1)**ind)*distances.pop()
if (ind % gap_int == 0) and (len(gaps) > 0):
nextrow += gaps.pop()
nextrow = keep_bounds(nextrow, max_locs[0])
nextcol = keep_bounds(nextcol, max_locs[1])
locs[ind, :] = [nextrow, nextcol]
return [locs[:, 0], locs[:, 1]]
class TestLocalMaxima1d:
def test_empty(self):
"""Test with empty signal."""
x = np.array([], dtype=np.float64)
for array in _local_maxima_1d(x):
assert_equal(array, np.array([]))
assert_(array.base is None)
def test_linear(self):
"""Test with linear signal."""
x = np.linspace(0, 100)
for array in _local_maxima_1d(x):
assert_equal(array, np.array([]))
assert_(array.base is None)
def test_simple(self):
"""Test with simple signal."""
x = np.linspace(-10, 10, 50)
x[2::3] += 1
expected = np.arange(2, 50, 3)
for array in _local_maxima_1d(x):
# For plateaus of size 1, the edges are identical with the
# midpoints
assert_equal(array, expected)
assert_(array.base is None)
def test_flat_maxima(self):
"""Test if flat maxima are detected correctly."""
x = np.array([-1.3, 0, 1, 0, 2, 2, 0, 3, 3, 3, 2.99, 4, 4, 4, 4, -10,
-5, -5, -5, -5, -5, -10])
midpoints, left_edges, right_edges = _local_maxima_1d(x)
assert_equal(midpoints, np.array([2, 4, 8, 12, 18]))
assert_equal(left_edges, np.array([2, 4, 7, 11, 16]))
assert_equal(right_edges, np.array([2, 5, 9, 14, 20]))
@pytest.mark.parametrize('x', [
np.array([1., 0, 2]),
np.array([3., 3, 0, 4, 4]),
np.array([5., 5, 5, 0, 6, 6, 6]),
])
def test_signal_edges(self, x):
"""Test if behavior on signal edges is correct."""
for array in _local_maxima_1d(x):
assert_equal(array, np.array([]))
assert_(array.base is None)
def test_exceptions(self):
"""Test input validation and raised exceptions."""
with raises(ValueError, match="wrong number of dimensions"):
_local_maxima_1d(np.ones((1, 1)))
with raises(ValueError, match="expected 'const float64_t'"):
_local_maxima_1d(np.ones(1, dtype=int))
with raises(TypeError, match="list"):
_local_maxima_1d([1., 2.])
with raises(TypeError, match="'x' must not be None"):
_local_maxima_1d(None)
class TestRidgeLines:
def test_empty(self):
test_matr = np.zeros([20, 100])
lines = _identify_ridge_lines(test_matr, np.full(20, 2), 1)
assert_(len(lines) == 0)
def test_minimal(self):
test_matr = np.zeros([20, 100])
test_matr[0, 10] = 1
lines = _identify_ridge_lines(test_matr, np.full(20, 2), 1)
assert_(len(lines) == 1)
test_matr = np.zeros([20, 100])
test_matr[0:2, 10] = 1
lines = _identify_ridge_lines(test_matr, np.full(20, 2), 1)
assert_(len(lines) == 1)
def test_single_pass(self):
distances = [0, 1, 2, 5]
gaps = [0, 1, 2, 0, 1]
test_matr = np.zeros([20, 50]) + 1e-12
length = 12
line = _gen_ridge_line([0, 25], test_matr.shape, length, distances, gaps)
test_matr[line[0], line[1]] = 1
max_distances = np.full(20, max(distances))
identified_lines = _identify_ridge_lines(test_matr, max_distances, max(gaps) + 1)
assert_array_equal(identified_lines, [line])
def test_single_bigdist(self):
distances = [0, 1, 2, 5]
gaps = [0, 1, 2, 4]
test_matr = np.zeros([20, 50])
length = 12
line = _gen_ridge_line([0, 25], test_matr.shape, length, distances, gaps)
test_matr[line[0], line[1]] = 1
max_dist = 3
max_distances = np.full(20, max_dist)
#This should get 2 lines, since the distance is too large
identified_lines = _identify_ridge_lines(test_matr, max_distances, max(gaps) + 1)
assert_(len(identified_lines) == 2)
for iline in identified_lines:
adists = np.diff(iline[1])
np.testing.assert_array_less(np.abs(adists), max_dist)
agaps = np.diff(iline[0])
np.testing.assert_array_less(np.abs(agaps), max(gaps) + 0.1)
def test_single_biggap(self):
distances = [0, 1, 2, 5]
max_gap = 3
gaps = [0, 4, 2, 1]
test_matr = np.zeros([20, 50])
length = 12
line = _gen_ridge_line([0, 25], test_matr.shape, length, distances, gaps)
test_matr[line[0], line[1]] = 1
max_dist = 6
max_distances = np.full(20, max_dist)
#This should get 2 lines, since the gap is too large
identified_lines = _identify_ridge_lines(test_matr, max_distances, max_gap)
assert_(len(identified_lines) == 2)
for iline in identified_lines:
adists = np.diff(iline[1])
np.testing.assert_array_less(np.abs(adists), max_dist)
agaps = np.diff(iline[0])
np.testing.assert_array_less(np.abs(agaps), max(gaps) + 0.1)
def test_single_biggaps(self):
distances = [0]
max_gap = 1
gaps = [3, 6]
test_matr = np.zeros([50, 50])
length = 30
line = _gen_ridge_line([0, 25], test_matr.shape, length, distances, gaps)
test_matr[line[0], line[1]] = 1
max_dist = 1
max_distances = np.full(50, max_dist)
#This should get 3 lines, since the gaps are too large
identified_lines = _identify_ridge_lines(test_matr, max_distances, max_gap)
assert_(len(identified_lines) == 3)
for iline in identified_lines:
adists = np.diff(iline[1])
np.testing.assert_array_less(np.abs(adists), max_dist)
agaps = np.diff(iline[0])
np.testing.assert_array_less(np.abs(agaps), max(gaps) + 0.1)
class TestArgrel:
def test_empty(self):
# Regression test for gh-2832.
# When there are no relative extrema, make sure that
# the number of empty arrays returned matches the
# dimension of the input.
empty_array = np.array([], dtype=int)
z1 = np.zeros(5)
i = argrelmin(z1)
assert_equal(len(i), 1)
assert_array_equal(i[0], empty_array)
z2 = np.zeros((3,5))
row, col = argrelmin(z2, axis=0)
assert_array_equal(row, empty_array)
assert_array_equal(col, empty_array)
row, col = argrelmin(z2, axis=1)
assert_array_equal(row, empty_array)
assert_array_equal(col, empty_array)
def test_basic(self):
# Note: the docstrings for the argrel{min,max,extrema} functions
# do not give a guarantee of the order of the indices, so we'll
# sort them before testing.
x = np.array([[1, 2, 2, 3, 2],
[2, 1, 2, 2, 3],
[3, 2, 1, 2, 2],
[2, 3, 2, 1, 2],
[1, 2, 3, 2, 1]])
row, col = argrelmax(x, axis=0)
order = np.argsort(row)
assert_equal(row[order], [1, 2, 3])
assert_equal(col[order], [4, 0, 1])
row, col = argrelmax(x, axis=1)
order = np.argsort(row)
assert_equal(row[order], [0, 3, 4])
assert_equal(col[order], [3, 1, 2])
row, col = argrelmin(x, axis=0)
order = np.argsort(row)
assert_equal(row[order], [1, 2, 3])
assert_equal(col[order], [1, 2, 3])
row, col = argrelmin(x, axis=1)
order = np.argsort(row)
assert_equal(row[order], [1, 2, 3])
assert_equal(col[order], [1, 2, 3])
def test_highorder(self):
order = 2
sigmas = [1.0, 2.0, 10.0, 5.0, 15.0]
test_data, act_locs = _gen_gaussians_even(sigmas, 500)
test_data[act_locs + order] = test_data[act_locs]*0.99999
test_data[act_locs - order] = test_data[act_locs]*0.99999
rel_max_locs = argrelmax(test_data, order=order, mode='clip')[0]
assert_(len(rel_max_locs) == len(act_locs))
assert_((rel_max_locs == act_locs).all())
def test_2d_gaussians(self):
sigmas = [1.0, 2.0, 10.0]
test_data, act_locs = _gen_gaussians_even(sigmas, 100)
rot_factor = 20
rot_range = np.arange(0, len(test_data)) - rot_factor
test_data_2 = np.vstack([test_data, test_data[rot_range]])
rel_max_rows, rel_max_cols = argrelmax(test_data_2, axis=1, order=1)
for rw in range(0, test_data_2.shape[0]):
inds = (rel_max_rows == rw)
assert_(len(rel_max_cols[inds]) == len(act_locs))
assert_((act_locs == (rel_max_cols[inds] - rot_factor*rw)).all())
class TestPeakProminences:
def test_empty(self):
"""
Test if an empty array is returned if no peaks are provided.
"""
out = peak_prominences([1, 2, 3], [])
for arr, dtype in zip(out, [np.float64, np.intp, np.intp]):
assert_(arr.size == 0)
assert_(arr.dtype == dtype)
out = peak_prominences([], [])
for arr, dtype in zip(out, [np.float64, np.intp, np.intp]):
assert_(arr.size == 0)
assert_(arr.dtype == dtype)
def test_basic(self):
"""
Test if height of prominences is correctly calculated in signal with
rising baseline (peak widths are 1 sample).
"""
# Prepare basic signal
x = np.array([-1, 1.2, 1.2, 1, 3.2, 1.3, 2.88, 2.1])
peaks = np.array([1, 2, 4, 6])
lbases = np.array([0, 0, 0, 5])
rbases = np.array([3, 3, 5, 7])
proms = x[peaks] - np.max([x[lbases], x[rbases]], axis=0)
# Test if calculation matches handcrafted result
out = peak_prominences(x, peaks)
assert_equal(out[0], proms)
assert_equal(out[1], lbases)
assert_equal(out[2], rbases)
def test_edge_cases(self):
"""
Test edge cases.
"""
# Peaks have same height, prominence and bases
x = [0, 2, 1, 2, 1, 2, 0]
peaks = [1, 3, 5]
proms, lbases, rbases = peak_prominences(x, peaks)
assert_equal(proms, [2, 2, 2])
assert_equal(lbases, [0, 0, 0])
assert_equal(rbases, [6, 6, 6])
# Peaks have same height & prominence but different bases
x = [0, 1, 0, 1, 0, 1, 0]
peaks = np.array([1, 3, 5])
proms, lbases, rbases = peak_prominences(x, peaks)
assert_equal(proms, [1, 1, 1])
assert_equal(lbases, peaks - 1)
assert_equal(rbases, peaks + 1)
def test_non_contiguous(self):
"""
Test with non-C-contiguous input arrays.
"""
x = np.repeat([-9, 9, 9, 0, 3, 1], 2)
peaks = np.repeat([1, 2, 4], 2)
proms, lbases, rbases = peak_prominences(x[::2], peaks[::2])
assert_equal(proms, [9, 9, 2])
assert_equal(lbases, [0, 0, 3])
assert_equal(rbases, [3, 3, 5])
def test_wlen(self):
"""
Test if wlen actually shrinks the evaluation range correctly.
"""
x = [0, 1, 2, 3, 1, 0, -1]
peak = [3]
# Test rounding behavior of wlen
assert_equal(peak_prominences(x, peak), [3., 0, 6])
for wlen, i in [(8, 0), (7, 0), (6, 0), (5, 1), (3.2, 1), (3, 2), (1.1, 2)]:
assert_equal(peak_prominences(x, peak, wlen), [3. - i, 0 + i, 6 - i])
def test_exceptions(self):
"""
Verify that exceptions and warnings are raised.
"""
# x with dimension > 1
with raises(ValueError, match='1-D array'):
peak_prominences([[0, 1, 1, 0]], [1, 2])
# peaks with dimension > 1
with raises(ValueError, match='1-D array'):
peak_prominences([0, 1, 1, 0], [[1, 2]])
# x with dimension < 1
with raises(ValueError, match='1-D array'):
peak_prominences(3, [0,])
# empty x with supplied
with raises(ValueError, match='not a valid index'):
peak_prominences([], [0])
# invalid indices with non-empty x
for p in [-100, -1, 3, 1000]:
with raises(ValueError, match='not a valid index'):
peak_prominences([1, 0, 2], [p])
# peaks is not cast-able to np.intp
with raises(TypeError, match='cannot safely cast'):
peak_prominences([0, 1, 1, 0], [1.1, 2.3])
# wlen < 3
with raises(ValueError, match='wlen'):
peak_prominences(np.arange(10), [3, 5], wlen=1)
def test_warnings(self):
"""
Verify that appropriate warnings are raised.
"""
msg = "some peaks have a prominence of 0"
for p in [0, 1, 2]:
with warns(PeakPropertyWarning, match=msg):
peak_prominences([1, 0, 2], [p,])
with warns(PeakPropertyWarning, match=msg):
peak_prominences([0, 1, 1, 1, 0], [2], wlen=2)
class TestPeakWidths:
def test_empty(self):
"""
Test if an empty array is returned if no peaks are provided.
"""
widths = peak_widths([], [])[0]
assert_(isinstance(widths, np.ndarray))
assert_equal(widths.size, 0)
widths = peak_widths([1, 2, 3], [])[0]
assert_(isinstance(widths, np.ndarray))
assert_equal(widths.size, 0)
out = peak_widths([], [])
for arr in out:
assert_(isinstance(arr, np.ndarray))
assert_equal(arr.size, 0)
@pytest.mark.filterwarnings("ignore:some peaks have a width of 0")
def test_basic(self):
"""
Test a simple use case with easy to verify results at different relative
heights.
"""
x = np.array([1, 0, 1, 2, 1, 0, -1])
prominence = 2
for rel_height, width_true, lip_true, rip_true in [
(0., 0., 3., 3.), # raises warning
(0.25, 1., 2.5, 3.5),
(0.5, 2., 2., 4.),
(0.75, 3., 1.5, 4.5),
(1., 4., 1., 5.),
(2., 5., 1., 6.),
(3., 5., 1., 6.)
]:
width_calc, height, lip_calc, rip_calc = peak_widths(
x, [3], rel_height)
assert_allclose(width_calc, width_true)
assert_allclose(height, 2 - rel_height * prominence)
assert_allclose(lip_calc, lip_true)
assert_allclose(rip_calc, rip_true)
def test_non_contiguous(self):
"""
Test with non-C-contiguous input arrays.
"""
x = np.repeat([0, 100, 50], 4)
peaks = np.repeat([1], 3)
result = peak_widths(x[::4], peaks[::3])
assert_equal(result, [0.75, 75, 0.75, 1.5])
def test_exceptions(self):
"""
Verify that argument validation works as intended.
"""
with raises(ValueError, match='1-D array'):
# x with dimension > 1
peak_widths(np.zeros((3, 4)), np.ones(3))
with raises(ValueError, match='1-D array'):
# x with dimension < 1
peak_widths(3, [0])
with raises(ValueError, match='1-D array'):
# peaks with dimension > 1
peak_widths(np.arange(10), np.ones((3, 2), dtype=np.intp))
with raises(ValueError, match='1-D array'):
# peaks with dimension < 1
peak_widths(np.arange(10), 3)
with raises(ValueError, match='not a valid index'):
# peak pos exceeds x.size
peak_widths(np.arange(10), [8, 11])
with raises(ValueError, match='not a valid index'):
# empty x with peaks supplied
peak_widths([], [1, 2])
with raises(TypeError, match='cannot safely cast'):
# peak cannot be safely casted to intp
peak_widths(np.arange(10), [1.1, 2.3])
with raises(ValueError, match='rel_height'):
# rel_height is < 0
peak_widths([0, 1, 0, 1, 0], [1, 3], rel_height=-1)
with raises(TypeError, match='None'):
# prominence data contains None
peak_widths([1, 2, 1], [1], prominence_data=(None, None, None))
def test_warnings(self):
"""
Verify that appropriate warnings are raised.
"""
msg = "some peaks have a width of 0"
with warns(PeakPropertyWarning, match=msg):
# Case: rel_height is 0
peak_widths([0, 1, 0], [1], rel_height=0)
with warns(PeakPropertyWarning, match=msg):
# Case: prominence is 0 and bases are identical
peak_widths(
[0, 1, 1, 1, 0], [2],
prominence_data=(np.array([0.], np.float64),
np.array([2], np.intp),
np.array([2], np.intp))
)
def test_mismatching_prominence_data(self):
"""Test with mismatching peak and / or prominence data."""
x = [0, 1, 0]
peak = [1]
for i, (prominences, left_bases, right_bases) in enumerate([
((1.,), (-1,), (2,)), # left base not in x
((1.,), (0,), (3,)), # right base not in x
((1.,), (2,), (0,)), # swapped bases same as peak
((1., 1.), (0, 0), (2, 2)), # array shapes don't match peaks
((1., 1.), (0,), (2,)), # arrays with different shapes
((1.,), (0, 0), (2,)), # arrays with different shapes
((1.,), (0,), (2, 2)) # arrays with different shapes
]):
# Make sure input is matches output of signal.peak_prominences
prominence_data = (np.array(prominences, dtype=np.float64),
np.array(left_bases, dtype=np.intp),
np.array(right_bases, dtype=np.intp))
# Test for correct exception
if i < 3:
match = "prominence data is invalid for peak"
else:
match = "arrays in `prominence_data` must have the same shape"
with raises(ValueError, match=match):
peak_widths(x, peak, prominence_data=prominence_data)
@pytest.mark.filterwarnings("ignore:some peaks have a width of 0")
def test_intersection_rules(self):
"""Test if x == eval_height counts as an intersection."""
# Flatt peak with two possible intersection points if evaluated at 1
x = [0, 1, 2, 1, 3, 3, 3, 1, 2, 1, 0]
# relative height is 0 -> width is 0 as well, raises warning
assert_allclose(peak_widths(x, peaks=[5], rel_height=0),
[(0.,), (3.,), (5.,), (5.,)])
# width_height == x counts as intersection -> nearest 1 is chosen
assert_allclose(peak_widths(x, peaks=[5], rel_height=2/3),
[(4.,), (1.,), (3.,), (7.,)])
def test_unpack_condition_args():
"""
Verify parsing of condition arguments for `scipy.signal.find_peaks` function.
"""
x = np.arange(10)
amin_true = x
amax_true = amin_true + 10
peaks = amin_true[1::2]
# Test unpacking with None or interval
assert_((None, None) == _unpack_condition_args((None, None), x, peaks))
assert_((1, None) == _unpack_condition_args(1, x, peaks))
assert_((1, None) == _unpack_condition_args((1, None), x, peaks))
assert_((None, 2) == _unpack_condition_args((None, 2), x, peaks))
assert_((3., 4.5) == _unpack_condition_args((3., 4.5), x, peaks))
# Test if borders are correctly reduced with `peaks`
amin_calc, amax_calc = _unpack_condition_args((amin_true, amax_true), x, peaks)
assert_equal(amin_calc, amin_true[peaks])
assert_equal(amax_calc, amax_true[peaks])
# Test raises if array borders don't match x
with raises(ValueError, match="array size of lower"):
_unpack_condition_args(amin_true, np.arange(11), peaks)
with raises(ValueError, match="array size of upper"):
_unpack_condition_args((None, amin_true), np.arange(11), peaks)
class TestFindPeaks:
# Keys of optionally returned properties
property_keys = {'peak_heights', 'left_thresholds', 'right_thresholds',
'prominences', 'left_bases', 'right_bases', 'widths',
'width_heights', 'left_ips', 'right_ips'}
def test_constant(self):
"""
Test behavior for signal without local maxima.
"""
open_interval = (None, None)
peaks, props = find_peaks(np.ones(10),
height=open_interval, threshold=open_interval,
prominence=open_interval, width=open_interval)
assert_(peaks.size == 0)
for key in self.property_keys:
assert_(props[key].size == 0)
def test_plateau_size(self):
"""
Test plateau size condition for peaks.
"""
# Prepare signal with peaks with peak_height == plateau_size
plateau_sizes = np.array([1, 2, 3, 4, 8, 20, 111])
x = np.zeros(plateau_sizes.size * 2 + 1)
x[1::2] = plateau_sizes
repeats = np.ones(x.size, dtype=int)
repeats[1::2] = x[1::2]
x = np.repeat(x, repeats)
# Test full output
peaks, props = find_peaks(x, plateau_size=(None, None))
assert_equal(peaks, [1, 3, 7, 11, 18, 33, 100])
assert_equal(props["plateau_sizes"], plateau_sizes)
assert_equal(props["left_edges"], peaks - (plateau_sizes - 1) // 2)
assert_equal(props["right_edges"], peaks + plateau_sizes // 2)
# Test conditions
assert_equal(find_peaks(x, plateau_size=4)[0], [11, 18, 33, 100])
assert_equal(find_peaks(x, plateau_size=(None, 3.5))[0], [1, 3, 7])
assert_equal(find_peaks(x, plateau_size=(5, 50))[0], [18, 33])
def test_height_condition(self):
"""
Test height condition for peaks.
"""
x = (0., 1/3, 0., 2.5, 0, 4., 0)
peaks, props = find_peaks(x, height=(None, None))
assert_equal(peaks, np.array([1, 3, 5]))
assert_equal(props['peak_heights'], np.array([1/3, 2.5, 4.]))
assert_equal(find_peaks(x, height=0.5)[0], np.array([3, 5]))
assert_equal(find_peaks(x, height=(None, 3))[0], np.array([1, 3]))
assert_equal(find_peaks(x, height=(2, 3))[0], np.array([3]))
def test_threshold_condition(self):
"""
Test threshold condition for peaks.
"""
x = (0, 2, 1, 4, -1)
peaks, props = find_peaks(x, threshold=(None, None))
assert_equal(peaks, np.array([1, 3]))
assert_equal(props['left_thresholds'], np.array([2, 3]))
assert_equal(props['right_thresholds'], np.array([1, 5]))
assert_equal(find_peaks(x, threshold=2)[0], np.array([3]))
assert_equal(find_peaks(x, threshold=3.5)[0], np.array([]))
assert_equal(find_peaks(x, threshold=(None, 5))[0], np.array([1, 3]))
assert_equal(find_peaks(x, threshold=(None, 4))[0], np.array([1]))
assert_equal(find_peaks(x, threshold=(2, 4))[0], np.array([]))
def test_distance_condition(self):
"""
Test distance condition for peaks.
"""
# Peaks of different height with constant distance 3
peaks_all = np.arange(1, 21, 3)
x = np.zeros(21)
x[peaks_all] += np.linspace(1, 2, peaks_all.size)
# Test if peaks with "minimal" distance are still selected (distance = 3)
assert_equal(find_peaks(x, distance=3)[0], peaks_all)
# Select every second peak (distance > 3)
peaks_subset = find_peaks(x, distance=3.0001)[0]
# Test if peaks_subset is subset of peaks_all
assert_(
np.setdiff1d(peaks_subset, peaks_all, assume_unique=True).size == 0
)
# Test if every second peak was removed
assert_equal(np.diff(peaks_subset), 6)
# Test priority of peak removal
x = [-2, 1, -1, 0, -3]
peaks_subset = find_peaks(x, distance=10)[0] # use distance > x size
assert_(peaks_subset.size == 1 and peaks_subset[0] == 1)
def test_prominence_condition(self):
"""
Test prominence condition for peaks.
"""
x = np.linspace(0, 10, 100)
peaks_true = np.arange(1, 99, 2)
offset = np.linspace(1, 10, peaks_true.size)
x[peaks_true] += offset
prominences = x[peaks_true] - x[peaks_true + 1]
interval = (3, 9)
keep = np.nonzero(
(interval[0] <= prominences) & (prominences <= interval[1]))
peaks_calc, properties = find_peaks(x, prominence=interval)
assert_equal(peaks_calc, peaks_true[keep])
assert_equal(properties['prominences'], prominences[keep])
assert_equal(properties['left_bases'], 0)
assert_equal(properties['right_bases'], peaks_true[keep] + 1)
def test_width_condition(self):
"""
Test width condition for peaks.
"""
x = np.array([1, 0, 1, 2, 1, 0, -1, 4, 0])
peaks, props = find_peaks(x, width=(None, 2), rel_height=0.75)
assert_equal(peaks.size, 1)
assert_equal(peaks, 7)
assert_allclose(props['widths'], 1.35)
assert_allclose(props['width_heights'], 1.)
assert_allclose(props['left_ips'], 6.4)
assert_allclose(props['right_ips'], 7.75)
def test_properties(self):
"""
Test returned properties.
"""
open_interval = (None, None)
x = [0, 1, 0, 2, 1.5, 0, 3, 0, 5, 9]
peaks, props = find_peaks(x,
height=open_interval, threshold=open_interval,
prominence=open_interval, width=open_interval)
assert_(len(props) == len(self.property_keys))
for key in self.property_keys:
assert_(peaks.size == props[key].size)
def test_raises(self):
"""
Test exceptions raised by function.
"""
with raises(ValueError, match="1-D array"):
find_peaks(np.array(1))
with raises(ValueError, match="1-D array"):
find_peaks(np.ones((2, 2)))
with raises(ValueError, match="distance"):
find_peaks(np.arange(10), distance=-1)
@pytest.mark.filterwarnings("ignore:some peaks have a prominence of 0",
"ignore:some peaks have a width of 0")
def test_wlen_smaller_plateau(self):
"""
Test behavior of prominence and width calculation if the given window
length is smaller than a peak's plateau size.
Regression test for gh-9110.
"""
peaks, props = find_peaks([0, 1, 1, 1, 0], prominence=(None, None),
width=(None, None), wlen=2)
assert_equal(peaks, 2)
assert_equal(props["prominences"], 0)
assert_equal(props["widths"], 0)
assert_equal(props["width_heights"], 1)
for key in ("left_bases", "right_bases", "left_ips", "right_ips"):
assert_equal(props[key], peaks)
@pytest.mark.parametrize("kwargs", [
{},
{"distance": 3.0},
{"prominence": (None, None)},
{"width": (None, 2)},
])
def test_readonly_array(self, kwargs):
"""
Test readonly arrays are accepted.
"""
x = np.linspace(0, 10, 15)
x_readonly = x.copy()
x_readonly.flags.writeable = False
peaks, _ = find_peaks(x)
peaks_readonly, _ = find_peaks(x_readonly, **kwargs)
assert_allclose(peaks, peaks_readonly)
class TestFindPeaksCwt:
def test_find_peaks_exact(self):
"""
Generate a series of gaussians and attempt to find the peak locations.
"""
sigmas = [5.0, 3.0, 10.0, 20.0, 10.0, 50.0]
num_points = 500
test_data, act_locs = _gen_gaussians_even(sigmas, num_points)
widths = np.arange(0.1, max(sigmas))
found_locs = find_peaks_cwt(test_data, widths, gap_thresh=2, min_snr=0,
min_length=None)
np.testing.assert_array_equal(found_locs, act_locs,
"Found maximum locations did not equal those expected")
def test_find_peaks_withnoise(self):
"""
Verify that peak locations are (approximately) found
for a series of gaussians with added noise.
"""
sigmas = [5.0, 3.0, 10.0, 20.0, 10.0, 50.0]
num_points = 500
test_data, act_locs = _gen_gaussians_even(sigmas, num_points)
widths = np.arange(0.1, max(sigmas))
noise_amp = 0.07
np.random.seed(18181911)
test_data += (np.random.rand(num_points) - 0.5)*(2*noise_amp)
found_locs = find_peaks_cwt(test_data, widths, min_length=15,
gap_thresh=1, min_snr=noise_amp / 5)
np.testing.assert_equal(len(found_locs), len(act_locs), 'Different number' +
'of peaks found than expected')
diffs = np.abs(found_locs - act_locs)
max_diffs = np.array(sigmas) / 5
np.testing.assert_array_less(diffs, max_diffs, 'Maximum location differed' +
'by more than %s' % (max_diffs))
def test_find_peaks_nopeak(self):
"""
Verify that no peak is found in
data that's just noise.
"""
noise_amp = 1.0
num_points = 100
np.random.seed(181819141)
test_data = (np.random.rand(num_points) - 0.5)*(2*noise_amp)
widths = np.arange(10, 50)
found_locs = find_peaks_cwt(test_data, widths, min_snr=5, noise_perc=30)
np.testing.assert_equal(len(found_locs), 0)
def test_find_peaks_with_non_default_wavelets(self):
x = gaussian(200, 2)
widths = np.array([1, 2, 3, 4])
a = find_peaks_cwt(x, widths, wavelet=gaussian)
np.testing.assert_equal(np.array([100]), a)
def test_find_peaks_window_size(self):
"""
Verify that window_size is passed correctly to private function and
affects the result.
"""
sigmas = [2.0, 2.0]
num_points = 1000
test_data, act_locs = _gen_gaussians_even(sigmas, num_points)
widths = np.arange(0.1, max(sigmas), 0.2)
noise_amp = 0.05
np.random.seed(18181911)
test_data += (np.random.rand(num_points) - 0.5)*(2*noise_amp)
# Possibly contrived negative region to throw off peak finding
# when window_size is too large
test_data[250:320] -= 1
found_locs = find_peaks_cwt(test_data, widths, gap_thresh=2, min_snr=3,
min_length=None, window_size=None)
with pytest.raises(AssertionError):
assert found_locs.size == act_locs.size
found_locs = find_peaks_cwt(test_data, widths, gap_thresh=2, min_snr=3,
min_length=None, window_size=20)
assert found_locs.size == act_locs.size
def test_find_peaks_with_one_width(self):
"""
Verify that the `width` argument
in `find_peaks_cwt` can be a float
"""
xs = np.arange(0, np.pi, 0.05)
test_data = np.sin(xs)
widths = 1
found_locs = find_peaks_cwt(test_data, widths)
np.testing.assert_equal(found_locs, 32)