def test_high_order_derivative(x):
small_radius = ['sqrt', 'log', 'log2', 'log10', 'arccos', 'log1p',
'arcsin', 'arctan', 'arcsinh', 'tan', 'tanh',
'arctanh', 'arccosh']
r = 0.0061
n_max = 20
y = x
for name in function_names + ['arccosh', 'arctanh']:
f, true_df = get_function(name, n=1)
if name == 'arccosh':
y = y + 1
vals, info = derivative(f, y, r=r, n=n_max, full_output=True,
step_ratio=1.6)
for n in range(1, n_max):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
tval = true_df(y)
aerr0 = info.error_estimate[n] + 1e-15
aerr = min(aerr0, max(np.abs(tval)*1e-6, 1e-8))
print(n, name, y, vals[n], tval, info.iterations, aerr0, aerr)
note("{}, {}, {}, {}, {}, {}, {}, {}".format(
n, name, y, vals[n], tval, info.iterations,
aerr0, aerr))
assert_allclose(np.real(vals[n]), tval, rtol=1e-6, atol=aerr)
def test_high_order_derivative(x):
# small_radius = ['sqrt', 'log', 'log2', 'log10', 'arccos', 'log1p',
# 'arcsin', 'arctan', 'arcsinh', 'tan', 'tanh',
# 'arctanh', 'arccosh']
r = 0.0061
n_max = 20
y = x
for name in function_names + ['arccosh', 'arctanh']:
f, true_df = get_function(name, n=1)
if name == 'arccosh':
y = y + 1
vals, info = derivative(f,
y,
r=r,
n=n_max,
full_output=True,
step_ratio=1.6)
for n in range(1, n_max):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
tval = true_df(y)
aerr0 = info.error_estimate[n] + 1e-15
aerr = min(aerr0, max(np.abs(tval) * 1e-6, 1e-8))
print(n, name, y, vals[n], tval, info.iterations, aerr0, aerr)
note("{}, {}, {}, {}, {}, {}, {}, {}".format(
n, name, y, vals[n], tval, info.iterations, aerr0, aerr))
assert_allclose(np.real(vals[n]), tval, rtol=1e-6, atol=aerr)
def test_high_order_derivative():
x = 0.5
min_dm = dict(complex=2, forward=2, backward=2, central=4)
methods = ['complex', 'central', 'backward', 'forward']
derivatives = [nd.Derivative]
if nda is not None:
derivatives.append(nda.Derivative)
for i, derivative in enumerate(derivatives):
for name in function_names:
if i > 0 and name in ['arcsinh', 'exp2']:
continue
for n in range(1, 11):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
for method in methods[3 * i:]:
if i == 0 and n > 7 and method not in ['complex']:
continue
df = derivative(f, method=method, n=n, full_output=True)
val, info = df(x)
dm = max(int(-np.log10(info.error_estimate + 1e-16)) - 1,
min_dm.get(method, 4))
print(i, name, method, n, dm)
tval = true_df(x)
assert_array_almost_equal(val, tval, decimal=dm)
def _test_first_derivative(name):
x = np.linspace(0.0001, 0.98, 5)
h = _default_base_step(x, scale=2)
f, df = get_function(name, n=1)
der = f(bicomplex(x + h * 1j, 0)).imag1 / h
der_true = df(x)
np.testing.assert_allclose(der, der_true, err_msg=('{0!s}'.format(name)))
def _test_first_derivative(name):
x = np.linspace(0.0001, 0.98, 5)
h = _default_base_step(x, scale=2)
f, df = get_function(name, n=1)
der = f(bicomplex(x + h * 1j, 0)).imag1 / h
der_true = df(x)
np.testing.assert_allclose(der, der_true, err_msg=('{0!s}'.format(name)))
def _test_second_derivative(name):
x = np.linspace(0.01, 0.98, 5)
h = _default_base_step(x, scale=2.5)
# h = 1e-8
f, df = get_function(name, n=2)
der = f(bicomplex(x + h * 1j, h)).imag12 / h**2
der_true = df(x)
np.testing.assert_allclose(der, der_true, err_msg=('{0!s}'.format(name)))
def _test_second_derivative(name):
x = np.linspace(0.01, 0.98, 5)
h = _default_base_step(x, scale=2.5)
# h = 1e-8
f, df = get_function(name, n=2)
der = f(bicomplex(x + h * 1j, h)).imag12 / h**2
der_true = df(x)
np.testing.assert_allclose(der, der_true, err_msg=('{0!s}'.format(name)))
def test_high_order_derivative(self):
x = 0.5
methods = ['complex', 'central', 'forward', 'backward']
for name in function_names:
for n in range(2, 11):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
for method in methods:
if n>7 and method not in ['complex']:
continue
val = nd.Derivative(f, method=method, n=n)(x)
print(name, method, n)
assert_array_almost_equal(val, true_df(x), decimal=2)
def test_high_order_derivative(self):
x = 0.5
methods = ['complex', 'central', 'forward', 'backward']
for name in function_names:
for n in range(2, 11):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
for method in methods:
if n > 7 and method not in ['complex']:
continue
val = nd.Derivative(f, method=method, n=n)(x)
print(name, method, n)
assert_array_almost_equal(val, true_df(x), decimal=2)
def test_first_order_derivative(self):
x = 0.5
methods = ['complex', 'central', 'backward', 'forward']
for i, derivative in enumerate(
[nd.Derivative, nds.Gradient, nda.Derivative]):
for name in function_names:
if i > 1 and name in ['arcsinh', 'exp2']:
continue
f, true_df = get_function(name, n=1)
if true_df is None:
continue
for method in methods[3 * (i > 1):]:
df = derivative(f, method=method)
val = df(x)
tval = true_df(x)
dm = 7
print(i, name, method, dm, np.abs(val - tval))
assert_array_almost_equal(val, tval, decimal=dm)
def main():
x = 0.5
methods = ['complex', 'central', 'backward', 'forward']
# for i, Derivative in enumerate([nd.Derivative, nds.Gradient,
# nda.Derivative]):
i = 0
Derivative = nd.Derivative
for name in function_names:
if i > 1 and name in ['arcsinh', 'exp2']:
continue
f, true_df = get_function(name, n=1)
if true_df is None:
continue
for method in methods[3 * (i > 1):]:
df = Derivative(f, method=method)
val = df(x)
tval = true_df(x)
dm = 7
print(i, name, method, dm, np.abs(val - tval))
def test_high_order_derivative():
x = 0.5
min_dm = dict(complex=2, forward=2, backward=2, central=4)
methods = [ 'complex', 'central', 'backward', 'forward']
for i, derivative in enumerate([nd.Derivative, nda.Derivative]):
for name in function_names:
if i>0 and name in ['arcsinh', 'exp2']:
continue
for n in range(2, 11):
f, true_df = get_function(name, n=n)
if true_df is None:
continue
for method in methods[3*i:]:
if i==0 and n > 7 and method not in ['complex']:
continue
df = derivative(f, method=method, n=n, full_output=True)
val, info = df(x)
dm = max(int(-np.log10(info.error_estimate + 1e-16))-1,
min_dm.get(method, 4))
print(i, name, method, n, dm)
tval = true_df(x)
assert_array_almost_equal(val, tval, decimal=dm)
def run_all_benchmarks(method='forward',
order=4,
x_values=(0.1, 0.5, 1.0, 5),
n_max=11,
show_plot=True):
epsilon = MinStepGenerator(num_steps=3, scale=None, step_nom=None)
scales = {}
for n in range(1, n_max):
plt.figure(n)
scale_n = scales.setdefault(n, [])
# for (name, x) in itertools.product( function_names, x_values):
for name in function_names:
fun0, dfun = get_function(name, n)
if dfun is None:
continue
fd = Derivative(fun0,
step=epsilon,
method=method,
n=n,
order=order)
for x in x_values:
r = benchmark(x=x,
dfun=dfun,
fd=fd,
name=name,
scales=None,
show_plot=show_plot)
print(r)
scale = r['scale']
if np.isfinite(scale):
scale_n.append(scale)
plt.vlines(np.mean(scale_n), 1e-12, 1, 'r', linewidth=3)
plt.vlines(np.median(scale_n), 1e-12, 1, 'b', linewidth=3)
_print_summary(method, order, x_values, scales)
def _example3(x=0.0001,
fun_name='cos',
epsilon=None,
method='central',
scale=None,
n=1,
order=2):
fun0, dfun = get_function(fun_name, n)
if dfun is None:
return dict(n=n,
order=order,
method=method,
fun=fun_name,
error=np.nan,
scale=np.nan)
fd = Derivative(fun0, step=epsilon, method=method, n=n, order=order)
t = []
scales = np.arange(1.0, 35, 0.25)
for scale in scales:
fd.step.scale = scale
try:
val = fd(x)
except Exception:
val = np.nan
t.append(val)
t = np.array(t)
tt = dfun(x)
relativ_error = np.abs(t - tt) / (np.maximum(np.abs(tt), 1)) + 1e-16
# weights = np.ones((3,))/3
# relativ_error = convolve1d(relativ_error, weights) # smooth curve
if np.isnan(relativ_error).all():
return dict(n=n,
order=order,
method=method,
fun=fun_name,
error=np.nan,
scale=np.nan)
if True: # False: #
plt.semilogy(scales, relativ_error, label=fun_name)
plt.vlines(default_scale(fd.method, n, order),
np.nanmin(relativ_error), 1)
plt.xlabel('scales')
plt.ylabel('Relative error')
txt = ['', "1'st", "2'nd", "3'rd", "4'th", "5'th", "6'th", "7th"
] + ["%d'th" % i for i in range(8, 25)]
plt.title("The %s derivative using %s, order=%d" %
(txt[n], method, order))
plt.legend(frameon=False, framealpha=0.5)
plt.axis([min(scales), max(scales), np.nanmin(relativ_error), 1])
# plt.figure()
# plt.show('hold')
i = np.nanargmin(relativ_error)
return dict(n=n,
order=order,
method=method,
fun=fun_name,
error=relativ_error[i],
scale=scales[i])
