Python scipy.special.ellipk() Examples
The following are 16
code examples of scipy.special.ellipk().
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Example #1
| Source File: gradshafranov.py From freegs with GNU Lesser General Public License v3.0 | 6 votes |
|
def Greens(Rc, Zc, R, Z):
"""
Calculate poloidal flux at (R,Z) due to a unit current
at (Rc,Zc) using Greens function
"""
# Calculate k^2
k2 = 4.*R * Rc / ( (R + Rc)**2 + (Z - Zc)**2 )
# Clip to between 0 and 1 to avoid nans e.g. when coil is on grid point
k2 = clip(k2, 1e-10, 1.0 - 1e-10)
k = sqrt(k2)
# Note definition of ellipk, ellipe in scipy is K(k^2), E(k^2)
return (mu0/(2.*pi)) * sqrt(R*Rc) * ( (2. - k2)*ellipk(k2) - 2.*ellipe(k2) ) / k
Example #2
| Source File: filter_design.py From lambda-packs with MIT License | 5 votes |
|
def _kratio(m, k_ratio):
m = float(m)
if m < 0:
m = 0.0
if m > 1:
m = 1.0
if abs(m) > EPSILON and (abs(m) + EPSILON) < 1:
k = special.ellipk([m, 1 - m])
r = k[0] / k[1] - k_ratio
elif abs(m) > EPSILON:
r = -k_ratio
else:
r = 1e20
return abs(r)
Example #3
| Source File: filter_design.py From Computable with MIT License | 5 votes |
|
def _kratio(m, k_ratio):
m = float(m)
if m < 0:
m = 0.0
if m > 1:
m = 1.0
if abs(m) > EPSILON and (abs(m) + EPSILON) < 1:
k = special.ellipk([m, 1 - m])
r = k[0] / k[1] - k_ratio
elif abs(m) > EPSILON:
r = -k_ratio
else:
r = 1e20
return abs(r)
Example #4
| Source File: test_basic.py From Computable with MIT License | 5 votes |
|
def test_ellipk(self):
assert_allclose(ellipk(0), pi/2)
Example #5
| Source File: test_basic.py From Computable with MIT License | 5 votes |
|
def test_ellipk(self):
elk = special.ellipk(.2)
assert_almost_equal(elk,1.659623598610528,11)
Example #6
| Source File: test_basic.py From Computable with MIT License | 5 votes |
|
def test_ellipkinc(self):
elkinc = special.ellipkinc(pi/2,.2)
elk = special.ellipk(0.2)
assert_almost_equal(elkinc,elk,15)
alpha = 20*pi/180
phi = 45*pi/180
m = sin(alpha)**2
elkinc = special.ellipkinc(phi,m)
assert_almost_equal(elkinc,0.79398143,8)
# From pg. 614 of A & S
Example #7
| Source File: filter_design.py From GraphicDesignPatternByPython with MIT License | 5 votes |
|
def _kratio(m, k_ratio):
m = float(m)
if m < 0:
m = 0.0
if m > 1:
m = 1.0
if abs(m) > EPSILON and (abs(m) + EPSILON) < 1:
k = special.ellipk([m, 1 - m])
r = k[0] / k[1] - k_ratio
elif abs(m) > EPSILON:
r = -k_ratio
else:
r = 1e20
return abs(r)
Example #8
| Source File: test_basic.py From GraphicDesignPatternByPython with MIT License | 5 votes |
|
def test_ellipk(self):
assert_allclose(ellipk(0), pi/2)
Example #9
| Source File: test_basic.py From GraphicDesignPatternByPython with MIT License | 5 votes |
|
def test_ellipk(self):
elk = special.ellipk(.2)
assert_almost_equal(elk,1.659623598610528,11)
assert_equal(special.ellipkm1(0.0), np.inf)
assert_equal(special.ellipkm1(1.0), pi/2)
assert_equal(special.ellipkm1(np.inf), 0.0)
assert_equal(special.ellipkm1(np.nan), np.nan)
assert_equal(special.ellipkm1(-1), np.nan)
assert_allclose(special.ellipk(-10), 0.7908718902387385)
Example #10
| Source File: test_basic.py From GraphicDesignPatternByPython with MIT License | 5 votes |
|
def test_ellipkinc(self):
elkinc = special.ellipkinc(pi/2,.2)
elk = special.ellipk(0.2)
assert_almost_equal(elkinc,elk,15)
alpha = 20*pi/180
phi = 45*pi/180
m = sin(alpha)**2
elkinc = special.ellipkinc(phi,m)
assert_almost_equal(elkinc,0.79398143,8)
# From pg. 614 of A & S
assert_equal(special.ellipkinc(pi/2, 0.0), pi/2)
assert_equal(special.ellipkinc(pi/2, 1.0), np.inf)
assert_equal(special.ellipkinc(pi/2, -np.inf), 0.0)
assert_equal(special.ellipkinc(pi/2, np.nan), np.nan)
assert_equal(special.ellipkinc(pi/2, 2), np.nan)
assert_equal(special.ellipkinc(0, 0.5), 0.0)
assert_equal(special.ellipkinc(np.inf, 0.5), np.inf)
assert_equal(special.ellipkinc(-np.inf, 0.5), -np.inf)
assert_equal(special.ellipkinc(np.inf, np.inf), np.nan)
assert_equal(special.ellipkinc(np.inf, -np.inf), np.nan)
assert_equal(special.ellipkinc(-np.inf, -np.inf), np.nan)
assert_equal(special.ellipkinc(-np.inf, np.inf), np.nan)
assert_equal(special.ellipkinc(np.nan, 0.5), np.nan)
assert_equal(special.ellipkinc(np.nan, np.nan), np.nan)
assert_allclose(special.ellipkinc(0.38974112035318718, 1), 0.4, rtol=1e-14)
assert_allclose(special.ellipkinc(1.5707, -10), 0.79084284661724946)
Example #11
| Source File: test_mpmath.py From GraphicDesignPatternByPython with MIT License | 5 votes |
|
def test_ellipk(self):
assert_mpmath_equal(sc.ellipk,
mpmath.ellipk,
[Arg(b=1.0)])
assert_mpmath_equal(sc.ellipkm1,
lambda m: mpmath.ellipk(1 - m),
[Arg(a=0.0)],
dps=400)
Example #12
| Source File: filter_design.py From Splunking-Crime with GNU Affero General Public License v3.0 | 5 votes |
|
def _kratio(m, k_ratio):
m = float(m)
if m < 0:
m = 0.0
if m > 1:
m = 1.0
if abs(m) > EPSILON and (abs(m) + EPSILON) < 1:
k = special.ellipk([m, 1 - m])
r = k[0] / k[1] - k_ratio
elif abs(m) > EPSILON:
r = -k_ratio
else:
r = 1e20
return abs(r)
Example #13
| Source File: filter_design.py From lambda-packs with MIT License | 4 votes |
|
def band_stop_obj(wp, ind, passb, stopb, gpass, gstop, type):
"""
Band Stop Objective Function for order minimization.
Returns the non-integer order for an analog band stop filter.
Parameters
----------
wp : scalar
Edge of passband `passb`.
ind : int, {0, 1}
Index specifying which `passb` edge to vary (0 or 1).
passb : ndarray
Two element sequence of fixed passband edges.
stopb : ndarray
Two element sequence of fixed stopband edges.
gstop : float
Amount of attenuation in stopband in dB.
gpass : float
Amount of ripple in the passband in dB.
type : {'butter', 'cheby', 'ellip'}
Type of filter.
Returns
-------
n : scalar
Filter order (possibly non-integer).
"""
passbC = passb.copy()
passbC[ind] = wp
nat = (stopb * (passbC[0] - passbC[1]) /
(stopb ** 2 - passbC[0] * passbC[1]))
nat = min(abs(nat))
if type == 'butter':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = (log10((GSTOP - 1.0) / (GPASS - 1.0)) / (2 * log10(nat)))
elif type == 'cheby':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = arccosh(sqrt((GSTOP - 1.0) / (GPASS - 1.0))) / arccosh(nat)
elif type == 'ellip':
GSTOP = 10 ** (0.1 * gstop)
GPASS = 10 ** (0.1 * gpass)
arg1 = sqrt((GPASS - 1.0) / (GSTOP - 1.0))
arg0 = 1.0 / nat
d0 = special.ellipk([arg0 ** 2, 1 - arg0 ** 2])
d1 = special.ellipk([arg1 ** 2, 1 - arg1 ** 2])
n = (d0[0] * d1[1] / (d0[1] * d1[0]))
else:
raise ValueError("Incorrect type: %s" % type)
return n
Example #14
| Source File: filter_design.py From Computable with MIT License | 4 votes |
|
def band_stop_obj(wp, ind, passb, stopb, gpass, gstop, type):
"""
Band Stop Objective Function for order minimization.
Returns the non-integer order for an analog band stop filter.
Parameters
----------
wp : scalar
Edge of passband `passb`.
ind : int, {0, 1}
Index specifying which `passb` edge to vary (0 or 1).
passb : ndarray
Two element sequence of fixed passband edges.
stopb : ndarray
Two element sequence of fixed stopband edges.
gstop : float
Amount of attenuation in stopband in dB.
gpass : float
Amount of ripple in the passband in dB.
type : {'butter', 'cheby', 'ellip'}
Type of filter.
Returns
-------
n : scalar
Filter order (possibly non-integer).
"""
passbC = passb.copy()
passbC[ind] = wp
nat = (stopb * (passbC[0] - passbC[1]) /
(stopb ** 2 - passbC[0] * passbC[1]))
nat = min(abs(nat))
if type == 'butter':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = (log10((GSTOP - 1.0) / (GPASS - 1.0)) / (2 * log10(nat)))
elif type == 'cheby':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = arccosh(sqrt((GSTOP - 1.0) / (GPASS - 1.0))) / arccosh(nat)
elif type == 'ellip':
GSTOP = 10 ** (0.1 * gstop)
GPASS = 10 ** (0.1 * gpass)
arg1 = sqrt((GPASS - 1.0) / (GSTOP - 1.0))
arg0 = 1.0 / nat
d0 = special.ellipk([arg0 ** 2, 1 - arg0 ** 2])
d1 = special.ellipk([arg1 ** 2, 1 - arg1 ** 2])
n = (d0[0] * d1[1] / (d0[1] * d1[0]))
else:
raise ValueError("Incorrect type: %s" % type)
return n
Example #15
| Source File: filter_design.py From GraphicDesignPatternByPython with MIT License | 4 votes |
|
def band_stop_obj(wp, ind, passb, stopb, gpass, gstop, type):
"""
Band Stop Objective Function for order minimization.
Returns the non-integer order for an analog band stop filter.
Parameters
----------
wp : scalar
Edge of passband `passb`.
ind : int, {0, 1}
Index specifying which `passb` edge to vary (0 or 1).
passb : ndarray
Two element sequence of fixed passband edges.
stopb : ndarray
Two element sequence of fixed stopband edges.
gstop : float
Amount of attenuation in stopband in dB.
gpass : float
Amount of ripple in the passband in dB.
type : {'butter', 'cheby', 'ellip'}
Type of filter.
Returns
-------
n : scalar
Filter order (possibly non-integer).
"""
passbC = passb.copy()
passbC[ind] = wp
nat = (stopb * (passbC[0] - passbC[1]) /
(stopb ** 2 - passbC[0] * passbC[1]))
nat = min(abs(nat))
if type == 'butter':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = (log10((GSTOP - 1.0) / (GPASS - 1.0)) / (2 * log10(nat)))
elif type == 'cheby':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = arccosh(sqrt((GSTOP - 1.0) / (GPASS - 1.0))) / arccosh(nat)
elif type == 'ellip':
GSTOP = 10 ** (0.1 * gstop)
GPASS = 10 ** (0.1 * gpass)
arg1 = sqrt((GPASS - 1.0) / (GSTOP - 1.0))
arg0 = 1.0 / nat
d0 = special.ellipk([arg0 ** 2, 1 - arg0 ** 2])
d1 = special.ellipk([arg1 ** 2, 1 - arg1 ** 2])
n = (d0[0] * d1[1] / (d0[1] * d1[0]))
else:
raise ValueError("Incorrect type: %s" % type)
return n
Example #16
| Source File: filter_design.py From Splunking-Crime with GNU Affero General Public License v3.0 | 4 votes |
|
def band_stop_obj(wp, ind, passb, stopb, gpass, gstop, type):
"""
Band Stop Objective Function for order minimization.
Returns the non-integer order for an analog band stop filter.
Parameters
----------
wp : scalar
Edge of passband `passb`.
ind : int, {0, 1}
Index specifying which `passb` edge to vary (0 or 1).
passb : ndarray
Two element sequence of fixed passband edges.
stopb : ndarray
Two element sequence of fixed stopband edges.
gstop : float
Amount of attenuation in stopband in dB.
gpass : float
Amount of ripple in the passband in dB.
type : {'butter', 'cheby', 'ellip'}
Type of filter.
Returns
-------
n : scalar
Filter order (possibly non-integer).
"""
passbC = passb.copy()
passbC[ind] = wp
nat = (stopb * (passbC[0] - passbC[1]) /
(stopb ** 2 - passbC[0] * passbC[1]))
nat = min(abs(nat))
if type == 'butter':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = (log10((GSTOP - 1.0) / (GPASS - 1.0)) / (2 * log10(nat)))
elif type == 'cheby':
GSTOP = 10 ** (0.1 * abs(gstop))
GPASS = 10 ** (0.1 * abs(gpass))
n = arccosh(sqrt((GSTOP - 1.0) / (GPASS - 1.0))) / arccosh(nat)
elif type == 'ellip':
GSTOP = 10 ** (0.1 * gstop)
GPASS = 10 ** (0.1 * gpass)
arg1 = sqrt((GPASS - 1.0) / (GSTOP - 1.0))
arg0 = 1.0 / nat
d0 = special.ellipk([arg0 ** 2, 1 - arg0 ** 2])
d1 = special.ellipk([arg1 ** 2, 1 - arg1 ** 2])
n = (d0[0] * d1[1] / (d0[1] * d1[0]))
else:
raise ValueError("Incorrect type: %s" % type)
return n
