def pdf(a, b, d, l, m, x):
g = math.sqrt(a**2 - b**2)
ff = math.pow(g / d, l) * math.exp(
b * (x - m)) / (math.sqrt(2 * math.pi) * sp.kv(l, d * g))
ff *= sp.kv(l - 1 / 2, a * math.sqrt(d**2 + (x - m)**2)) / math.pow(
math.sqrt(d**2 + (x - m)**2) / a, 1 / 2 - l)
return ff
def dark_heff(self, td):
"""
Compute the effective d.o.f. in entropy of the dark sector.
Parameters
----------
td: float
The dark sector temperature.
"""
xe = self.m_eta() / td
xd = self.m_del() / td
ge = 1.0
gd = self.g_del()
pre = 45.0 / (4.0 * np.pi ** 4)
pree = pre * ge * xe ** 3
pred = pre * gd * xd ** 3
bess_sum_e = sum(
1.0 / (1.0 + k) * kv(3, (1.0 + k) * xe) for k in range(5)
)
bess_sum_d = kv(3, xd)
return pree * bess_sum_e + pred * bess_sum_d
def matern_full(d, params):
'''Evaluate Matern covariance function.
Inputs:
d -- float or array, shape (N, N), distance matrix
params -- array, shape (3,), hyperparameter vector -> [amplitude , lengthscale, order ]
Result:
float or array, shape (N,N), matern function corresponding to each distance.
'''
s, rho, v = params
mask = np.where(d == 0, False, True) # Avoids warnings
out = np.zeros_like(d)
try:
out[mask] = s**2 * (2**(1 - v)) * (
np.sqrt(2 * v) * d[mask] / rho)**v * spec.kv(
v,
np.sqrt(2 * v) * d[mask] / rho) / spec.gamma(v)
out[~mask] = s**2
except TypeError:
if d == 0:
out = s**2
else:
out = s**2 * (2
**(1 - v)) * (np.sqrt(2 * v) * d / rho)**v * spec.kv(
v,
np.sqrt(2 * v) * d / rho) / spec.gamma(v)
return out
def test_bessel(self):
n = 1000
ds = math.pi/n
ib0 = 0
ib1 = 0
x= 1.4
for j in range (0, n):
tt = (j - 0.5)*ds
ib0 += math.exp(x*math.cos(tt))*ds
ib1 += +math.exp(x*math.cos(tt))*ds*math.cos(tt)
ib0 = ib0/math.pi
ib1 = ib1/math.pi
kb0 = 0
kb1 = 0
ds = 2*math.pi/n
for j in range(0, n):
tt = (j - 0.5)*ds
ch = (math.exp(tt) + math.exp(-tt))/2
kb1 += math.exp(-x*ch)*ch*ds
kb0 += math.exp(-x*ch)*ds
i0 = sp.iv(0, x)
i1 = sp.iv(1, x)
k0 = sp.kv(0, x)
k1 = sp.kv(1, x)
self.assertTrue(((abs(ib0 - i0)<0.005)&(abs(ib1 - i1)<0.005)&(abs(kb0 - k0)<0.005)&(abs(kb1 - k1)<0.005)), msg = 'Deltas I0, I1, K0, K1: ' + str(abs(i0 - ib0)) + ', ' + str(abs(i1 - ib1)) + ', ' + str(abs(k0 - kb0)) + ', ' + str(abs(k1 - kb1)))
def cond_int_var(self, vovn, zhat):
m1 = self.condvar_m1(zhat, vovn)
m2 = self.condvar_m2(zhat, vovn)
m1m2_ratio = m2 / m1**2
m1 *= np.exp(zhat * vovn)
w2 = np.ones_like(zhat)
if self.dist.lower() == 'm1':
r_var = m1
r_vol = np.sqrt(r_var)
elif self.dist.lower() == 'ln':
r_var = m1 / np.sqrt(np.sqrt(m1m2_ratio))
r_vol = np.sqrt(r_var)
elif self.dist.lower() == 'ig': # inverse Gaussian
lam = m1 / (m1m2_ratio - 1.0)
r_var = 1 - 1 / (8 * lam) * (1 - 9 / (2 * 8 * lam) *
(1 - 25 / (6 * 8 * lam)))
r_var[lam < 100] = spsp.kv(0, lam[lam < 100]) / spsp.kv(
-0.5, lam[lam < 100])
r_var = m1 * r_var**2
r_vol = np.sqrt(r_var)
else:
pass
assert r_var.shape == w2.shape
return r_var, r_vol, w2
def constant_charge_single_energy(phi0, r1, kappa, epsilon):
N = 20 # Number of terms in expansion
qe = 1.60217646e-19
Na = 6.0221415e23
E_0 = 8.854187818e-12
cal2J = 4.184
index2 = arange(N+1, dtype=float) + 0.5
index = index2[0:-1]
K1 = special.kv(index2, kappa*r1)
K1p = index/(kappa*r1)*K1[0:-1] - K1[1:]
k1 = special.kv(index, kappa*r1)*sqrt(pi/(2*kappa*r1))
k1p = -sqrt(pi/2)*1/(2*(kappa*r1)**(3/2.))*special.kv(index, kappa*r1) + sqrt(pi/(2*kappa*r1))*K1p
a0_inf = -phi0/(epsilon*kappa*k1p[0])
U1_inf = a0_inf*k1[0]
C1 = 2*pi*phi0*r1*r1
C0 = qe**2*Na*1e-3*1e10/(cal2J*E_0)
E_inter = C0*C1*U1_inf
return E_inter
def psynch(gamma, nu, B):
"""
equation 13 from Chiaberge & Ghisellini. This is the single
particle synchrotron emissivity j_nu
averaged over an isotropic distribution of pitch angles.
Parameters:
gamma array-like
Lorentz factors of electrons
nu float
frequency in Hz
B float
magnetic field in Gauss
"""
nu_B = unit.e * B / 2.0 / np.pi / unit.melec / unit.c
t = nu / (3.0 * gamma * gamma * nu_B)
x = 3.0 * np.sqrt(
3.0) / np.pi * unit.thomson * unit.c * B * B / 8.0 / np.pi
x *= t * t / nu_B
# get the modified Bessel functions
K13 = special.kv(1.0 / 3.0, t)
K43 = special.kv(4.0 / 3.0, t)
K43sq = K43 * K43
K13sq = K13 * K13
kterm = (K13 * K43) - (0.6 * t * (K43sq - K13sq))
return x * kterm
def constant_charge_single_energy(phi0, r1, kappa, epsilon):
N = 20 # Number of terms in expansion
qe = 1.60217646e-19
Na = 6.0221415e23
E_0 = 8.854187818e-12
cal2J = 4.184
index2 = arange(N + 1, dtype=float) + 0.5
index = index2[0:-1]
K1 = special.kv(index2, kappa * r1)
K1p = index / (kappa * r1) * K1[0:-1] - K1[1:]
k1 = special.kv(index, kappa * r1) * sqrt(pi / (2 * kappa * r1))
k1p = -sqrt(pi / 2) * 1 / (2 * (kappa * r1)**(3 / 2.)) * special.kv(
index, kappa * r1) + sqrt(pi / (2 * kappa * r1)) * K1p
a0_inf = -phi0 / (epsilon * kappa * k1p[0])
U1_inf = a0_inf * k1[0]
C1 = 2 * pi * phi0 * r1 * r1
C0 = qe**2 * Na * 1e-3 * 1e10 / (cal2J * E_0)
E_inter = C0 * C1 * U1_inf
return E_inter
def magnetic_field(self, xy, field="secondary"):
"""Magnetic field due to a magnetic dipole over a half space
The analytic expression is only valid for a source and receiver at the
surface of the earth. For arbitrary source and receiver locations above
the earth, use the layered solution.
Parameters
----------
xy : numpy.ndarray
receiver locations of shape (n_locations, 2)
field : ("secondary", "total")
Flag for the type of field to return.
"""
sig = self.sigma_hat # (n_freq, )
f = self.frequency
w = 2*np.pi*f
k = np.sqrt(-1j*w*mu_0*sig)[:, None] # This will get it to broadcast over locations
dxy = xy[:, :2] - self.location[:2]
r = np.linalg.norm(dxy, axis=-1)
x = dxy[:, 0]
y = dxy[:, 1]
em_x = em_y = em_z = 0
src_x, src_y, src_z = self.orientation
# Z component of source
alpha = 1j*k*r/2.
IK1 = iv(1, alpha)*kv(1, alpha)
IK2 = iv(2, alpha)*kv(2, alpha)
if src_z != 0.0:
em_z += src_z*2.0/(k**2*r**5)*(9-(9+9*1j*k*r-4*k**2*r**2-1j*k**3*r**3)*np.exp(-1j*k*r))
Hr = (k**2/r)*(IK1 - IK2)
angle = np.arctan2(y, x)
em_x += src_z*np.cos(angle)*Hr
em_y += src_z*np.sin(angle)*Hr
if src_x != 0.0 or src_y != 0.0:
# X component of source
phi = 2/(k**2*r**4)*(3 + k**2*r**2 - (3 + 3j*k*r - k**2*r**2)*np.exp(-1j*k*r))
dphi_dr = 2/(k**2*r**5)*(-2*k**2*r**2 - 12 + (-1j*k**3*r**3 - 5*k**2*r**2 + 12j*k*r + 12)*np.exp(-1j*k*r))
if src_x != 0.0:
em_x += src_x*(-1.0/r**3)*(y**2*phi + x**2*r*dphi_dr)
em_y += src_x*(1.0/r**3)*x*y*(phi - r*dphi_dr)
em_z -= src_x*(k**2*x/r**2)*(IK1 - IK2)
# Y component of source
if src_y != 0.0:
em_x += src_y*(1.0/r**3)*x*y*(phi - r*dphi_dr)
em_y += src_y*(-1.0/r**3)*(x**2*phi + y**2*r*dphi_dr)
em_z -= src_y*(k**2*y/r**2)*(IK1 - IK2)
if field == "secondary":
# subtract out primary field from above
mdotr = src_x*x + src_y*y# + m[2]*(z=0)
em_x -= 3*x*mdotr/r**5 - src_x/r**3
em_y -= 3*y*mdotr/r**5 - src_y/r**3
em_z -= -src_z/r**3 # + 3*(z=0)*mdotr/r**5
return self.moment/(4*np.pi)*np.stack((em_x, em_y, em_z), axis=-1)
def __call__(self, X, Y=None, eval_gradient=False):
from scipy.spatial.distance import pdist, cdist, squareform
from scipy import special
X = np.atleast_2d(X)
if Y is None:
dists = pdist(X, metric='mahalanobis', VI=self.invLam)
Filter = (dists != 0.)
K = np.zeros_like(dists)
K[Filter] = dists[Filter] **(5./6.) * special.kv(5./6., 2*np.pi * dists[Filter])
lim0 = special.gamma(5./6.) /(2 * ((np.pi)**(5./6.)) )
K = squareform(K)
np.fill_diagonal(K, lim0)
K /= lim0
else:
if eval_gradient:
raise ValueError(
"Gradient can not be evaluated.")
dists = cdist(X, Y, metric='mahalanobis', VI=self.invLam)
Filter = (dists != 0.)
K = np.zeros_like(dists)
K[Filter] = dists[Filter] **(5./6.) * special.kv(5./6., 2*np.pi * dists[Filter])
lim0 = special.gamma(5./6.) /(2 * ((np.pi)**(5./6.)) )
if np.sum(Filter) != len(K[0])*len(K[:,0]):
K[~Filter] = lim0
K /= lim0
if eval_gradient:
raise ValueError(
"Gradient can not be evaluated.")
else:
return K
def Ep_clad(r, p, phase, pol, l, a, beta, u, w, s, A):
return (
1j * A * beta * ((a * jv(l, u)) / (w * kv(l, w)))
* ((1 - s) / 2 * kv(l-1, w * r / a)
- (1 + s) / 2 * kv(l+1, w * r / a))
* np.sin(l * p + pol) * np.exp(1j * phase)
)
def associateLPModeProfiles(modes, indexProfile):
'''
Associate the linearly polarized mode profile to the corresponding constants found solving the analytical dispersion relation.
see: "Weakly Guiding Fibers" by D. Golge in Applied Optics, 1971
'''
assert (not modes.profiles)
R = indexProfile.R
TH = indexProfile.TH
a = indexProfile.a
logger.info(
'Finding analytical LP mode profiles associated to the propagation constants.'
)
for idx in range(modes.number):
m = modes.m[idx]
l = modes.l[idx]
u = modes.u[idx]
w = modes.w[idx]
# two pi/2 rotated degenerate modes for m > 0
if (m, l) in zip(modes.m[:idx], modes.l[:idx]):
psi = np.pi / 2
else:
psi = 0
# Avoid division bt zero in the Bessel function
R[R < np.finfo(np.float32).eps] = np.finfo(np.float32).eps
# Non-zero transverse component
Et = ( jv(m,u/a*R)/jv(m,u)*np.cos(m*TH+psi)*(R <= a)+ \
kv(m,w/a*R)/kv(m,w)*np.cos(m*TH+psi)*(R > a))
modes.profiles.append(Et.ravel().astype(np.complex64))
modes.profiles[-1] = modes.profiles[-1] / np.sqrt(
np.sum(np.abs(modes.profiles[-1])**2))
return modes
def T(chi_phot):
coeff = 1./(np.pi * np.sqrt(3.) * chi_phot * chi_phot)
inner = lambda x : integ.quad(lambda s: np.sqrt(s)*spe.kv(1./3., 2./3. * s**(3./2.)), x, np.inf)[0]
return integ.quad(lambda chi_ele:
coeff*(inner(X(chi_phot, chi_ele)) -
(2.0 - chi_phot*np.power(X(chi_phot, chi_ele), 3./2.))*spe.kv(2./3., 2./3. *X(chi_phot, chi_ele)**(3./2.)) )
, 0, chi_phot)[0]
def dark_geff(self, td):
"""
Compute the effective d.o.f. in energy of the dark sector.
Parameters
----------
td: float
The dark sector temperature.
"""
xe = self.m_eta() / td
xd = self.m_del() / td
ge = 1.0
gd = self.g_del()
pre = 30.0 / (2.0 * np.pi ** 4)
pree = pre * ge * xe ** 2
pred = pre * gd * xd ** 2
bess_sum_e = sum(
1.0
/ (1.0 + k) ** 2
* (
(1.0 + k) * xe * kv(1, (1.0 + k) * xe)
+ 3.0 * kv(2, (1.0 + k) * xe)
)
for k in range(5)
)
bess_sum_d = xd * kv(1, xd) + 3.0 * kv(2, xd)
return pree * bess_sum_e + pred * bess_sum_d
def LPModeProfile(m,
psi,
u,
w,
a,
npoints,
areasize,
coordtype='cart',
forFFT=0,
inf_profile=False):
'''
Linearly polarized mode, see : "Weakly Guiding Fibers" by D. Golge in Applied Optics, 1971
'''
if (forFFT):
# If forFFT = 1, the center on the mode is half a pixel shifted for an easier access of the Fourier transform
# x = -1.*np.arange(npoints/2,-npoints/2,-1)*areasize/npoints+1e-9
x = np.arange(-npoints / 2, npoints / 2, 1) * areasize / npoints + 1e-9
# x = np.arange(-npoints/2*areasize/npoints,npoints/2*areasize/npoints,areasize/npoints)
else:
x = np.linspace(-areasize / 2, areasize / 2, npoints)
[X, Y] = np.meshgrid(x, x)
[TH, R] = cart2pol(X, Y)
if inf_profile: # infinite profile
Et = jv(m, u / a * R) / jv(m, u) * np.cos(m * TH + psi)
else:
# Non-zero transverse component
Et = ( jv(m,u/a*R)/jv(m,u)*np.cos(m*TH+psi)*(R <= a) + \
kv(m,w/a*R)/kv(m,w)*np.cos(m*TH+psi)*(R > a) )
Norm = np.sqrt(np.sum(np.abs(Et)**2))
return Et / Norm * np.sign(Et[npoints // 2, npoints // 2]), [X, Y]
def DeltaPs(s, rw, constantes, n, qw):
(k, fi, pin, re, h, u, ct, B0) = constantes
sn = math.sqrt(s/n)
a = qw*u/(2*math.pi*k*h)
b = s*sn*rw*(bessel.iv(1,sn*re)*bessel.kv(1,sn*rw)-bessel.iv(1,sn*rw)*bessel.kv(1,sn*re))
c = bessel.iv(0,sn*rw)*bessel.kv(1,sn*re)+bessel.iv(1,sn*re)*bessel.kv(0,sn*rw)
return a*c/b
def tester(r, zeta):
rin = zeta*r
A1 = kv(0,rin)/iv(0,rin)
B2 = iv(0,zeta)/kv(0,zeta)
temp = (iv(1,zeta)-B2*(A1*r*iv(1,rin)+kv(1,zeta)-r*kv(1,rin)))/(iv(1,zeta)-B2*kv(1,zeta))
return 1./(1-temp)
def radiation_theoric(self,omega,observation_angle):
gamma=self.Lorentz_factor()
X=gamma*observation_angle
y=omega/self.critical_frequency()
xi=y*0.5*np.sqrt((1.+X**2)**3)
cst=(3.*codata.alpha*(gamma**2)*1e-3*1e-6*self.I_current()*y**2)/(codata.e*4.*np.pi**2)
rad=((1.+X**2)**2)*((special.kv((2./3.),xi))**2+((X**2)/(1.+X**2))*(special.kv((2./3.),xi))**2)
return rad*cst
def Hp_clad(r, p, phase, pol, l, omega, a, n_2, u, w, s_2, A):
return (
-1j * A * omega * epsilon_0 * n_2 ** 2
* ((a * jv(l, u)) / (w * kv(l, w)))
* ((1 - s_2) / 2 * kv(l-1, w * r / a)
+ (1 + s_2) / 2 * kv(l+1, w * r / a))
* np.sin(l * p + pol) * np.exp(1j * phase)
)
def constant_potential_twosphere_identical(phi01, phi02, r1, r2, R, kappa, epsilon):
# From Carnie+Chan 1993
N = 20 # Number of terms in expansion
qe = 1.60217646e-19
Na = 6.0221415e23
E_0 = 8.854187818e-12
cal2J = 4.184
index = arange(N, dtype=float) + 0.5
k1 = special.kv(index, kappa*r1)*sqrt(pi/(2*kappa*r1))
k2 = special.kv(index, kappa*r2)*sqrt(pi/(2*kappa*r2))
i1 = special.iv(index, kappa*r1)*sqrt(pi/(2*kappa*r1))
i2 = special.iv(index, kappa*r2)*sqrt(pi/(2*kappa*r2))
B = zeros((N,N), dtype=float)
for n in range(N):
for m in range(N):
for nu in range(N):
if n>=nu and m>=nu:
g1 = gamma(n-nu+0.5)
g2 = gamma(m-nu+0.5)
g3 = gamma(nu+0.5)
g4 = gamma(m+n-nu+1.5)
f1 = factorial(n+m-nu)
f2 = factorial(n-nu)
f3 = factorial(m-nu)
f4 = factorial(nu)
Anm = g1*g2*g3*f1*(n+m-2*nu+0.5)/(pi*g4*f2*f3*f4)
kB = special.kv(n+m-2*nu+0.5,kappa*R)*sqrt(pi/(2*kappa*R))
B[n,m] += Anm*kB
M = zeros((N,N), float)
for i in range(N):
for j in range(N):
M[i,j] = (2*i+1)*B[i,j]*i1[i]
if i==j:
M[i,j] += k1[i]
RHS = zeros(N)
RHS[0] = phi01
a = solve(M,RHS)
a0 = a[0]
U = 4*pi * ( -pi/2 * a0/phi01 * 1/sinh(kappa*r1) + kappa*r1 + kappa*r1/tanh(kappa*r1) )
# print 'E: %f'%U
C0 = qe**2*Na*1e-3*1e10/(cal2J*E_0)
C1 = r1*epsilon*phi01*phi01
E_inter = U*C1*C0
return E_inter
def E_zeta(self, r, theta):
r0_ind = np.where(r <= self.a)
r1_ind = np.where(r > self.a)
temp = np.zeros(r.shape, dtype=np.complex128)
r0, r1 = r[r0_ind], r[r1_ind]
temp[r0_ind] = jv(self.n, self.u*r0/self.a)
temp[r1_ind] = jv(self.n, self.u) * \
kv(self.n, self.w*r1/self.a)/kv(self.n, self.w)
return temp*np.cos(self.n*theta), temp*np.cos(self.n*theta+pi/2)
def calc_P_clad(l, omega, a, n_2, beta, u, w, s, s_2, A):
return (
(np.pi / 4) * omega * epsilon_0 * n_2 ** 2 * beta * np.abs(A) ** 2
* ((a * jv(l, u)) / (w * kv(l, w))) ** 2
* ((1 - s) * (1 - s_2)
* integrate.quad(lambda r: r * kv(l-1, r) ** 2, a, np.inf)
+ (1 + s) * (1 + s_2)
* integrate.quad(lambda r: r * kv(l+1, r) ** 2, a, np.inf))
)
def ansInteg() :
a = sp.jv(3,2.7)**2 - sp.jv(4,2.7)*sp.jv(2,2.7)
j3 = sp.jv(3,2.7)
j2 = sp.jv(2,2.7)
j4 = sp.jv(4,2.7)
k2 = sp.kv(2,1.2)
k3 = sp.kv(3,1.2)
k4 = sp.kv(4,1.2)
b = (j3/k3)**2 *(k4*k2 - k3**2)
def system(vec,V,Delta):
ru,iu,rw,iw = vec
u = ru+1j*iu
w = rw+1j*iw
first = u**2+w**2 - V**2
second = jv(0,u)/u/jv(1,u) - (1-Delta)*kv(0,w)/w/kv(1,w)
return np.real(first), np.imag(first),np.real(second), np.imag(second)
def yukawa(self, n_g, l=0, gamma=1e-6):
"""Calculates the radial grid yukawa integral.
The the integral kernel for the Yukawa interaction:
\ _ _
exp(- /\ | r - r' |)
----------------------
_ _
| r - r' |
is defined as
__ __ \ r \ r * ^ ^
\ 4 || I_(l+0.5)(/\ <) K_(l+0.5) (/\ >) Y (r) Y(r')
) -------------------------- lm lm
/ __ (rr')^0.5
lm
where I and K are the modified Bessel functions of the first
and second kind (K is also known as Macdonald function).
r = min (r, r') r = max(r, r')
< >
We now calculate the integral:
^ / _ ^
v (r) Y (r) = |dr' n(r') Y (r')
l lm / l lm
with the Yukawa kernel mentioned above.
And the output array is 'vr' as it is
within the Hartree / radial Poisson solver.
"""
from scipy.special import iv, kv
vr_g = self.zeros()
nrdr_g = n_g * self.r_g**1.5 * self.dr_g
p = 0
q = 0
k_rgamma = kv(l + 0.5, self.r_g * gamma) # K(>)
i_rgamma = iv(l + 0.5, self.r_g * gamma) # I(<)
k_rgamma[0] = kv(l + 0.5, self.r_g[1] * gamma * 1e-5)
# We have two integrals: one for r< and one for r>
# This loop-technique helps calculate them in once
for g_ind in range(len(nrdr_g) - 1, -1, -1):
dp = k_rgamma[g_ind] * nrdr_g[g_ind] # r' is r>
dq = i_rgamma[g_ind] * nrdr_g[g_ind] # r' is r<
vr_g[g_ind] = (p + 0.5 * dp) * i_rgamma[g_ind] - \
(q + 0.5 * dq) * k_rgamma[g_ind]
p += dp
q += dq
vr_g[:] += q * k_rgamma[:]
vr_g *= 4 * pi
vr_g[:] *= self.r_g[:]**0.5
return vr_g
def plot4(V=10, nguess=100, wavelength = 10**-6, a = 5*10**-6, l=0, eps=10**-4):
lguess = [0]*nguess
for i in range(nguess):
lguess[i]=i*V*1.1/nguess
lguess.append(V)
functy = lambda x: (V**2-x*x)**(1/2)
functj = lambda x: x*jv(l+1, x)/jv(l, x)
functk = lambda x: functy(x)*kv(l+1, functy(x))/kv(l, functy(x))
funct = lambda x: functj(x)-functk(x)
lroots = [0] * len(lguess)
for i in range(len(lroots)):
lroots[i] = fsolve(funct, lguess[i])
#print lroots
lx = np.linspace(0,V+2, 10000)
plt.scatter(lx, functj(lx), s=.5)
plt.plot(lx, functk(lx))
#plt.plot(lx, funct(lx))
plt.ylim([0, max(functk(lx))])
#sorry this bit isn't particularly clean. Had to change strategies. Lazy. Etc.
def floatequals(a,b, eps=10**-6):
if type(b)==float:
b=[b]
for number in b:
if abs(a-number)<eps:
return True
return False
roots=[]
for i in range(len(lroots)):
if lroots[i]<0:
continue
if lroots[i]==lguess[i]:
continue
if floatequals(lroots[i], roots, eps=eps):
continue
roots.extend(lroots[i])
print roots
plt.scatter(roots, functj(roots), c='red')
#plt.show()
plt.scatter(roots, map(functk, roots), c='red')
title='Characteristic equation for a fiber optic, recall that Y^2=V^2-X^2'
plt.title(title, size='small')
plt.xlabel('X')
plt.ylabel('X*J_(l+1)(X)/J_l(X) and Y*K_(l+1)(Y)/K_l(Y)')
plt.savefig('hw9-4.png')
print 'the roots are ' + str(roots)
print min(roots)
print functk(0)
plt.show()
plt.close()
def fdem_hy(self, freq, m=1.):
r = self.r
sigma = 1 / self.res
omega = freq * 2 * np.pi
k = np.sqrt(-1j * mu_0 * sigma * omega)
arg = 1.j * k * r / 2
h_r = - m * k * k / (4 * np.pi * r)
h_r *= (iv(1, arg) * kv(1, arg) - iv(2, arg) * kv(2, arg))
h_y = h_r * self.sin_phi
return h_y
def calc_vert_dist(e_relative):
G = (e_relative / 2.0) * (gamma_psi**(1.5))
K13_G = kv(1.0 / 3.0, G)
K23_G = kv(2.0 / 3.0, G)
dN_dOmega = (1.33e13) * (E**2) * I * (e_relative**2) * (gamma_psi**2)
dN_dOmega *= ((K23_G**2) + (((gamma**2) * (psi**2)) / (gamma_psi)) *
(K13_G**2))
return dN_dOmega
def coupling(a1, a2, n1_1, n1_2, n2, V1, V2, u1, u2, d):
delta_1 = (n1_1**2 - n2**2) / (2 * n1_1**2)
delta_2 = (n1_2**2 - n2**2) / (2 * n1_2**2)
w1 = np.sqrt(V1**2 - u1**2)
w2 = np.sqrt(V2**2 - u2**2)
first = np.sqrt(2 / (a1 * a2))
second = (delta_1 * delta_2 / (V1**6 * V2**6))**(1 / 4)
third = u1 * u2 * kv(0, w1 * d / a1) / (kv(1, w1) * kv(1, w2))
return first * second * third
def gammaCirc(ni, Re):
# Funzione idrodinamica per cantilever a sezione circolare
Re = np.sqrt(Re/2) - 1j*np.sqrt(Re/2)
num = 4*sx.kv(1,Re)
den = Re*sx.kv(0,Re)
return (1 + (num/den))
def radiation_theoric(self, omega, observation_angle):
gamma = self.Lorentz_factor()
X = gamma * observation_angle
y = omega / self.critical_frequency()
xi = y * 0.5 * np.sqrt((1. + X**2)**3)
cst = (3. * codata.alpha * (gamma**2) * 1e-3 * 1e-6 *
self.I_current() * y**2) / (codata.e * 4. * np.pi**2)
rad = ((1. + X**2)**2) * ((special.kv(
(2. / 3.), xi))**2 + ((X**2) / (1. + X**2)) * (special.kv(
(2. / 3.), xi))**2)
return rad * cst
def v_circ_exp(xkpc, param, arrsize=1500.):
'''
function for a rotation curve
that turns over and declines
at large radii
'''
# exponential disk model velocity curve (Freeman 1970; Equation 10)
# v^2 = R^2*!PI*G*nu0*a*(I0K0-I1K1)
# param = [r0,s0,v0,roff,theta]
# r0 = 1/a = disk radii
# R = radial distance
# roff = offset of velocity curve
# from 0 -> might want to set to fixed at 0?)
# s0 = nu0 = surface density constant (nu(R) = nu0*exp(-aR))
# v0 is the overall velocity offset
# G
G = 6.67408e-11 #m*kg^-1*(m/s)^2
G = G * 1.989e30 #m*Msol^-1*(m/s)^2
G = G / 3.0857e19 #kpc*Msol^-1(m/s)^2
G = G / 1000. / 1000.
# parameters
r0 = param[0]
s0 = 10**np.double(param[1])
v0 = param[2]
roff = param[3]
theta = param[4]
# evaluate bessel functions (evaluated at 0.5aR; see Freeman70)
rr = 0.025 * np.arange(arrsize) + 0.001 # set up an array
#rr = 0.025*np.arange(15000.)+0.001
temp = (0.5 * (rr) / r0)
temp[temp > 709.] = 709.
I0K0 = iv(0, temp) * kv(0, temp)
I1K1 = iv(1, temp) * kv(1, temp)
bsl = I0K0 - I1K1
# velocity curve
v2a = rr * ((np.pi * G * s0 * bsl) / r0)**0.5
v2a = v2a * np.sin(np.pi * theta / 180.)
# reflect the rotation curve
rr_r = np.append(-np.array(rr), np.array(rr))
v2_r = np.append(-np.array(v2a), np.array(v2a))
rrb = np.sort(rr_r) #rr_r(sort(rr_r))
v2b = v2_r[np.argsort(rr_r)] #v2_r(sort(rr_r))
# regrid back onto kpc scale and velocity offset
f = scipy.interpolate.interp1d(rrb, v2b, bounds_error=False)
v2 = f(xkpc - roff) + v0
return v2
def get_u(u, w, l, V):
with np.errstate(divide='ignore', invalid='ignore'):
# Retourne le membre de gauche et le membre de droite de l'équation des modes LP
left = jv(l, u) / (u * jv(l - 1, u))
right = -kv(l, w) / (w * kv(l - 1, w))
# Trouve les indices d'intersection entre le membre de gauche et de droite de l'équation de modes LP
idx = np.argwhere(np.diff(np.sign(left - right))).flatten()
# Calcule les valeurs de u correspondant à l'indice
u_values = get_intersects(u, idx, V)
return u_values, [left, right
], f'l = {l}; {len(u_values)} intersects: {u_values}'
def fdem_hz(self, freq, m=1.):
r = self.r
x = self.x
y = self.y
sigma = 1 / self.res
omega = freq * 2 * np.pi
k = np.sqrt(-1j * mu_0 * sigma * omega)
arg = 1.j * k * r / 2
h_z = m * k ** 2 * x / (4 * np.pi * r ** 2)
h_z *= iv(1, arg) * kv(1, arg) - iv(2, arg) * kv(2, arg)
return h_z
def AnalyticalSolution(nu, l, c, R):
# Modified Bessel function of the second kind of real order v :
from scipy.special import kv
F = 8.0*(1.0-nu)*((l**2)/(c**2)) * \
1.0 / (( 4.0 + ((R**2)/(c**2)) + \
((2.0*R)/c) * kv(0,R/c)/kv(1,R/c) ))
SCF = (3.0 + F) / (1.0 + F) # stress concentration factor
return SCF
def Psy(a, b, g):
c = np.abs(a) * np.sqrt(2 + b**2)
u = b / np.sqrt(2 + b**2)
value = ( c**(g+0.5) * np.exp(np.sign(a)*c) * (1+u)**g ) / ( np.sqrt(2*np.pi) * g * scps.gamma(g) ) * \
scps.kv(g+0.5 ,c) * Phi( g,1-g,1+g, (1+u)/2, -np.sign(a)*c*(1+u) ) - \
np.sign(a) * ( c**(g+0.5) * np.exp(np.sign(a)*c) * (1+u)**(1+g) ) / ( np.sqrt(2*np.pi) * (g+1) * scps.gamma(g) ) *\
scps.kv(g-0.5 ,c) * Phi( g+1,1-g,2+g, (1+u)/2, -np.sign(a)*c*(1+u) ) + \
np.sign(a) * ( c**(g+0.5) * np.exp(np.sign(a)*c) * (1+u)**(1+g) ) / ( np.sqrt(2*np.pi) * (g+1) * scps.gamma(g) ) *\
scps.kv(g-0.5 ,c) * Phi( g,1-g,1+g, (1+u)/2, -np.sign(a)*c*(1+u) )
return value
def inLaplace_mode2(s, r, ri, p0, pi, c, alpha, G, M11):
xi = r * (s / c)**0.5
beta = ri * (s / c)**0.5
p_2 = -(p0 - pi) / s * kv(0., xi) / kv(0., beta)
sig_rr_2 = -(p0 - pi) / s * (2. * G * alpha) / M11 * (
ri / r * kv(1., xi) - ri**2. / r**2 * kv(1., beta)) / (beta *
kv(0., beta))
sig_tt_2 = (p0 - pi) / s * (2. * G * alpha) / M11 * (
(ri / r * kv(1., xi) - ri**2. / r**2 * kv(1., beta)) /
(beta * kv(0., beta)) + kv(0., xi) / kv(0., beta))
return [p_2, sig_rr_2, sig_tt_2]
def C(k):
"""@brief Theodorsen's function.
@param k Reduced frequency.
@return C Function value, complex type.
"""
# Theodorsen's Function
if k < 0.0:
raise Exception('Reduced frequency should not be negative.')
elif k == 0.0:
return complex(1.0,0.0)
else:
return kv(1, complex(0, k)) / (kv(0, complex(0, k)) +
kv(1, complex(0, k)))
def atmSF(model, D, m, wlum, zen, r0inmRef):
"""
create the atmosphere phase structure function
model = 'Kolm'
= 'vonK'
"""
r0a = r0Wz(r0inmRef, zen, wlum)
L0 = 30 # outer scale in meter, only used when model=vonK
m0 = np.rint(0.5 * (m + 1) + 1e-5)
aa = np.arange(1, m + 1)
x, y = np.meshgrid(aa, aa)
dr = D / (m - 1) # frequency resolution in 1/rad
r = dr * np.sqrt((x - m0)**2 + (y - m0)**2)
if model == 'Kolm':
sfa = 6.88 * (r / r0a)**(5 / 3)
elif model == 'vonK':
sfa_c = 2 * sp.gamma(11 / 6) / 2**(5 / 6) / np.pi**(8 / 3) *\
(24 / 5 * sp.gamma(6 / 5))**(5 / 6) * (r0a / L0)**(-5 / 3)
# modified bessel of 2nd/3rd kind
sfa_k = sp.kv(5 / 6, (2 * np.pi / L0 * r))
sfa = sfa_c * (2**(-1 / 6) * sp.gamma(5 / 6) -
(2 * np.pi / L0 * r)**(5 / 6) * sfa_k)
# if we don't do below, everything will be nan after ifft2
# midp = r.shape[0]/2+1
# 1e-2 is to avoid x.49999 be rounded to x
midp = np.rint(0.5 * (r.shape[0] - 1) + 1e-2)
sfa[midp, midp] = 0 # at this single point, sfa_k=Inf, 0*Inf=Nan;
return sfa
def MED2(p,T,m,n,dim):
""" p,T,m,n,dim """
de = T/50
ef = 4.5
normconst = (2./m*k*T)**((dim-1)/2.)/sqrt(pi) *sp.kv((dim+1)/2.,(1.*m)/(k*T))*Gamma((dim/2.))
energy = zeros([1,n])
enrange = arange(m+0.1,ef,de)
Juttner = zeros([1,len(enrange)])
m2 = m**2
dim = double(dim)
for i in range(n):
energy[0,i] = sqrt((p[i].dot(p[i]))+m2)
g= 0
for E in enrange:
Juttner[0,g] = (n*de)*(1/normconst)*((E**2 -m**2)/(m**2))**(dim/2.)*(E/(E**2-m**2))*e**(-E/(k*T))
g+= 1
weights = ones([1,n])
y,binEdges=np.histogram(energy[0],bins=len(enrange),range=(m+0.1,ef),weights=weights[0])
menStd = sqrt((y-(y/n)))
errorbar(enrange,y, yerr=menStd, fmt='ro')
plot(enrange,Juttner[0])
numwithin = 0
for i in range(len(enrange)):
if (y[i]+menStd[i] >= Juttner[0,i]) and (y[i]-menStd[i] <= Juttner[0,i]):
numwithin+= 1
print((numwithin*100)/len(enrange), "% are within 1 standard dev")
def fundamental3D( cot ):
'''
plots fundamental solution in 3D
'''
x = dic[cot.mesh_name].source
V = cot.V
mesh_obj = cot.mesh_obj
kappa = cot.kappa
y = cot.mesh_obj.coordinates()
x_y = x-y
ra = x_y * x_y
ra = np.sum( ra, axis = 1 )
ra = np.sqrt( ra ) + 1e-13
kappara = kappa * ra
phi_arr = cot.factor * np.power( kappara, 0.5 ) * sp.kv( 0.5, kappara )
phi = Function( V )
phi.vector().set_local( phi_arr[dof_to_vertex_map(V)] )
helper.save_plots( phi,
["Free Space", "Greens Function"],
cot )
def SteMat(h,r,kappa):
# Matern isotropic covariance function (Stein's parameterization)
n = numpy.size(h)
corelation = numpy.zeros(n,dtype=numpy.double)
for i in range(n):
if h[i] == 0.0:
corelation[i] = 1.0
else:
hr=numpy.double(h[i])/r
bes=kv(kappa,2.0*numpy.sqrt(kappa)*hr)
if not numpy.isfinite(bes):
corelation[i] = 1.0
elif bes == 0.0:
corelation[i] = 0.0
else:
mult = 2.0**(1.0 - kappa)/gamma(kappa)*(2.0*numpy.sqrt(kappa)*hr)**kappa
if not numpy.isfinite(mult):
corelation[i] = 0.0
else:
corelation[i] = bes * mult
return corelation
def MaternARD(X,Y,theta,white_noise=False): """ Matern covariance kernel - not fully tested! different length scales in all inputs theta[0] - overall scale param - ie prior covariance theta[1] - shape parameter theta[2:-1] - length scales theta[-1] - white noise """ #Calculate distance matrix with scaling D = EuclideanDist(X,Y,v=theta[2:-1]) #Calculate covariance matrix from matern function v = theta[1] K = 2**(1.-v) / gamma(v) * (np.sqrt(2*v)*D)**v * kv(v,np.sqrt(2*v)*D) #diagonal terms should be set to one (when D2 = 0, kv diverges but full function = 1) #this only works for square 'covariance' matrix... #ie fails for blocks..; # K[np.where(np.identity(X[:,0].size)==1)] = 1. #this should work, but again needs tested properly... K[np.where(D==0.)] = 1. #now multiply by an overall scale function K = K * theta[0] #Add white noise if white_noise == True: K += np.identity(X[:,0].size) * (theta[-1]**2) return np.matrix(K)
def _F(x):
""" This is F(x) defined in equation 6.31c in R&L.
F(x) = x*int(K_5/3(x)dx) where the integral goes from x to infinity.
for some reason, special.kv(5/3,1e10) is NaN, not 0 ???
for now, just clip the function above 1e5 to be 0.
This function can be evaluated in mathematica using the following command
F[x_] := N[x*Integrate[BesselK[5/3, y], {y, x, Infinity}]]
From mathematica, we find that
x F(x)
----- ------------
0.1 0.818186
1 0.651423
10 0.000192238
100 0
Comparing our function to the Mathematica integral, we find
>>> np.allclose(Synchrotron.F([0.1,1,10,100]), [0.818186, 0.651423, 0.000192238,0], rtol=1e-4, atol=1e-4)
True
Note, this function is _F so that the docstring will get executed.
"""
if x>1e5: return 0
return x*integrate.quad(lambda j: special.kv(5./3,j),x,inf)[0]
def flux_distrib(self):
"""
:return: flux in ph/sec/mrad**2/0.1%BW
"""
C_om = 1.3255e22 #ph/(sec * rad**2 * GeV**2 * A)
g = self.gamma
#self.eph_c = 1.
ksi = lambda w,t: 1./2.*w * (1. + g*g*t*t)**(3./2.)
F = lambda w, t: (1.+g*g*t*t)**2 * (1.+
g*g*t*t/(1.+g*g*t*t) * (kv(1./3.,ksi(w, t))/kv(2./3.,ksi(w, t)))**2)
dw_over_w = 0.001 # 0.1% BW
mrad2 = 1e-6 # transform rad to mrad
I = lambda eph, theta: mrad2*C_om * self.energy**2*self.I* dw_over_w* (eph/self.eph_c)**2 * kv(2./3.,ksi(eph/self.eph_c,theta))**2 * F(eph/self.eph_c, theta)
return I
def MaternRad(X,Y,theta,white_noise=False): """ Matern covariance kernel - not properly tested! Radial - ie same length scales in all inputs """ #Calculate distance matrix with (global) scaling D = EuclideanDist(X,Y) / theta[2] #Calculate covariance matrix from matern function v = theta[1] K = 2.**(1.-v) / gamma(v) * (np.sqrt(2.*v)*D)**v * kv(v,np.sqrt(2.*v)*D) #diagonal terms should be set to one (when D2 = 0, kv diverges but full function = 1) #this only works for square 'covariance' matrix... #ie fails for blocks..; # K[np.where(np.identity(X[:,0].size)==1)] = 1. #this should work, but again needs tested properly... K[np.where(D==0.)] = 1. #now multiply by an overall scale function K = K * theta[0]**2 #Add white noise if white_noise == True: K += np.identity(X[:,0].size) * (theta[3]**2) return np.matrix(K)
def phase_covariance(r, r0, L0):
"""
Calculate the phase covariance between two points seperated by `r`,
in turbulence with a given `r0 and `L0`.
Uses equation 5 from Assemat and Wilson, 2006.
Parameters:
r (float, ndarray): Seperation between points in metres (can be ndarray)
r0 (float): Fried parameter of turbulence in metres
L0 (float): Outer scale of turbulence in metres
"""
# Make sure everything is a float to avoid nasty surprises in division!
r = numpy.float32(r)
r0 = float(r0)
L0 = float(L0)
# Get rid of any zeros
r += 1e-40
A = (L0 / r0) ** (5. / 3)
B1 = (2 ** (-5. / 6)) * gamma(11. / 6) / (numpy.pi ** (8. / 3))
B2 = ((24. / 5) * gamma(6. / 5)) ** (5. / 6)
C = (((2 * numpy.pi * r) / L0) ** (5. / 6)) * kv(5. / 6, (2 * numpy.pi * r) / L0)
cov = A * B1 * B2 * C
return cov
def pdf_one_point(x=0.0, c=0.0, sigma=1.0, theta=0.0, nu=1.0): ''' VarGamma probability density function in a point x ''' temp1 = 2.0 / ( sigma*(2.0*pi)**0.5*nu**(1/nu)*special.gamma(1/nu) ) temp2 = ((2*sigma**2/nu+theta**2)**0.5)**(0.5-1/nu) temp3 = exp(theta*(x-c)/sigma**2) * abs(x-c)**(1/nu - 0.5) temp4 = special.kv(1/nu - 0.5, abs(x-c)*(2*sigma**2/nu+theta**2)**0.5/sigma**2) return temp1*temp2*temp3*temp4
def FrankelStoppingPower(E0,T): # Frankel (PRA 1979) - formula 5.10. # Only ee collisions. # E0 : initial electron energy (MeV) # T : background plasma temperature (MeV) E0_ = np.double(E0) n = E0_.size v1 = np.double(np.sqrt(1.-(E0_/.511+1.)**-2)) g1 = np.double((1.-v1**2)**(-0.5)) a = .511/T y = np.zeros(n) for k in range(n): if E0_[k] < 0.1: pmin=g1[k]*v1[k]*(1.-g1[k]**2/4.) pmax=g1[k]*v1[k]*(1.+g1[k]**2/4.) dp = (pmax-pmin)/1000000. y[k] = quad(lambda p: tot1(p,v1[k],a), 0. ,pmin ,epsrel=3.e-14)[0] y[k]+= quad(lambda p: tot1(p,v1[k],a), pmin ,pmax-dp,epsrel=3.e-14)[0] y[k]+= quad(lambda p: tot1(p,v1[k],a), pmax ,np.inf ,epsrel=3.e-14)[0] y[k]+= quad(lambda p: tot (p,v1[k],a), 0. ,np.inf ,epsrel=3.e-14)[0] else: y[k] = quad(lambda p: tot (p,v1[k],a), 0. ,np.inf ,epsrel=3.e-14)[0] y[k]+= quad(lambda p: tot1(p,v1[k],a), 0. ,np.inf ,epsrel=3.e-14)[0] y *= (a/(4.*np.pi*kv(2,a)))/v1 y *= 3.204e-24 # 8*pi^2*me*c^2*re^2 in MeV*cm^2 return y
def th_roc_glq(mod_order, snr_db, n_samples, n_thresh, n_terms, fading, *args):
"""
Computes the theorectical CROC using the Gauss-Laguerre quadrature.
Parameters
----------
mod_order : int
Modulation order.
snr_db : float
Signal-to-noise ratio in dB.
n_samples : int
Number of transmitted symbols.
n_thresh : int
Number of thresholds to be evaluated.
n_terms : int
Number of terms for the Gauss-Laguerre quadrature.
fading : str
Name of the fading.
args : array-like
Fading parameters.
"""
if fading not in FADINGS:
raise NotImplementedError('the formulations for this fading is not'
' implemented yet.')
thresholds = np.linspace(.0, 100.0, n_thresh)
# symbol energy
Es = 1./mod_order
# noise variance
var_w = Es*sps.exp10(-snr_db/10.)
Pf = 1 - sps.gammainc(n_samples/2., thresholds/(2*var_w))
Pm = 0.0
printProgress(0, n_terms, prefix='Progress', suffix='Complete', barLength=50)
if fading == 'exp_weibull':
beta, alpha, eta = args[0:3]
roots, weights = sps.orthogonal.la_roots(n_terms, 0.0)
for k in range(n_terms):
Pm = Pm + (weights[k] * (1 - math.exp(-roots[k]))**(alpha - 1))*(1 - marcumQ(math.sqrt(n_samples * Es * (eta * roots[k]**(1./beta))**2 / var_w), np.sqrt(thresholds / var_w), n_samples / 2.0))
printProgress(k, n_terms-1, prefix='Progress', suffix='Complete', barLength=50)
Pm = alpha*Pm
elif fading == 'gamma_gamma':
beta, alpha = args[0:2]
roots, weights = sps.orthogonal.la_roots(n_terms, 0.5*(alpha + beta))
for k in range(n_terms):
Pm = Pm + weights[k] * math.exp(roots[k]) * kv(alpha - beta, 2 * math.sqrt(alpha * beta * roots[k])) * (1 - marcumQ(roots[k] * math.sqrt(n_samples * Es /var_w), np.sqrt(thresholds / var_w), n_samples / 2.0))
printProgress(k, n_terms-1, prefix='Progress', suffix='Complete', barLength=50)
Pm = Pm * 2 * (alpha * beta)**(0.5 * (alpha + beta)) / (gamma(alpha) * gamma(beta))
return Pf, Pm
def cvm_unif_inf(statistic):
"""
Calculates the limiting distribution of the Cramer-von Mises statistic.
After the second line of equation 1.3 from the Csorgo and Faraway paper.
"""
args = inf_args / statistic
return (inf_cs * exp(-args) * kv(.25, args)).sum() / statistic ** .5
def P1(self):
U = self.U
W = self.W
return W**2/U**2 * kv(1, W)**2/jv(1, U)**2 * (
(1-self.s)**2 * (jv(0, U)**2 + jv(1, U)**2) +
(1+self.s)**2 * (jv(2, U)**2 - jv(1, U)*jv(3, U)) +
2*U**2/self.rb**2 * (jv(1, U)**2 - jv(0, U)*jv(2, U))
)
def denom3D(x0, x1, x2, kappa, n):
ra = np.sqrt(x0 * x0 + x1 * x1 + x2 * x2) + 1e-9
kappara = kappa * ra
Khalf = sp.kv(0.5, kappara)
expon = np.exp(-kappara)
tmp = Khalf * expon / np.sqrt(ra)
return 2.0 * np.sum(tmp)
def integrate_yukawa(self, n1, n2, l, gamma):
"""Integrate two densities n1 and n2 with yukawa interaction."""
from scipy.special import iv, kv
r = self.r_g
dr = self.dr_g
k_rgamma = kv(l + 0.5, r * gamma) # K(>)
i_rgamma = iv(l + 0.5, r * gamma) # I(<)
k_rgamma[0] = kv(l + 0.5, r[1] * gamma * 1e-5)
matrix_ik = np.outer(n1 * dr, n2 * dr)
len_vec = len(k_rgamma)
for i in xrange(len_vec):
k_rgi = k_rgamma[i]
for k in xrange(i):
modified_bessels = i_rgamma[k] * k_rgi
matrix_ik[i, k] *= modified_bessels
matrix_ik[k, i] *= modified_bessels
matrix_ik[i, i] *= i_rgamma[i] * k_rgi
return matrix_ik.sum()
def Cgw_reg_year(alphaab,times_f,alpha=-2/3,fL=1.0/500,fH=None,decompose=False):
t1, t2 = N.meshgrid(times_f,times_f)
x = 2 * math.pi * (day/year) * fL * N.abs(t1 - t2)
# print N.min(x), N.max(x), N.max(t2 - t1)
year100ns = 1.0 # was year100ns = year/1e-7 for Ggw_reg_year
norm = (year100ns**2 * fL**(2*alpha - 2)) * 2**(alpha - 3) / (3 * math.pi**1.5 * SS.gamma(1.5 - alpha))
if fH is not None:
# introduce a high-frequency cutoff
xi = fH/fL
# avoid the gamma singularity at alpha = 1
if abs(alpha - 1) < 1e-6:
diag = math.log(xi) + (EulerGamma + math.log(0.5 * xi)) * math.log(xi) * (alpha - 1)
else:
diag = 2**(-alpha) * SS.gamma(1 - alpha) * (1 - xi**(2*alpha - 2))
with numpy_seterr(divide='ignore'):
bessel = N.where(xi*x > 1e3,0.0,SS.kv(1 - alpha,xi * x))
if decompose:
corr = N.where(x==0,0.0,x**(1 - alpha) * (SS.kv(1 - alpha,x) - xi**(alpha - 1) * bessel) - diag)
else:
corr = N.where(x==0,norm * diag,norm * x**(1 - alpha) * (SS.kv(1 - alpha,x) - xi**(alpha - 1) * bessel))
else:
if decompose:
diag = 2**(-alpha) * SS.gamma(1 - alpha)
corr = N.where(x==0,0,x**(1 - alpha) * SS.kv(1 - alpha,x) - diag)
else:
# testing for zero is dangerous, but kv seems to behave OK for arbitrarily small arguments
corr = N.where(x==0,norm * 2**(-alpha) * SS.gamma(1 - alpha),
norm * x**(1 - alpha) * SS.kv(1 - alpha,x))
ps, ts = len(alphaab), len(times_f) / len(alphaab)
for i in range(ps):
for j in range(ps):
corr[i*ts:(i+1)*ts,j*ts:(j+1)*ts] *= alphaab[i,j]
if decompose:
return norm, diag, corr
else:
return corr
def I1RK1r(self, rin, iaq, ipint):
r = rin / self.aq.lab2[iaq, ipint]
R = self.R / self.aq.lab2[iaq, ipint]
if np.isinf(self.i1R[iaq, ipint]).any():
rv = np.sqrt(1 / (4 * r * R)) * np.exp(R - r) * \
(1 - 3 / (8 * R) - 15 / (128 * R ** 2) - 315 / (3072 * R ** 3)) * \
(1 + 3 / (8 * r) - 15 / (128 * r ** 2) + 315 / (3072 * r ** 3))
else:
rv = self.i1R[iaq, ipint] * kv(1, r)
return rv
def th_roc_num(mod_order, snr_db, n_samples, n_thresh, fading, *args):
"""
Computes the theorectical CROC using the scipy numerical integration
library.
Parameters
----------
mod_order : int
Modulation order.
snr_db : float
Signal-to-noise ratio in dB.
n_samples : int
Number of transmitted symbols.
n_thresh : int
Number of thresholds to be evaluated.
n_terms : int
Number of terms for the Gauss-Laguerre quadrature.
fading : str
Name of the fading.
args : array-like
Fading parameters.
"""
if fading not in FADINGS:
raise NotImplementedError('the formulations for this fading is not'
' implemented yet.')
thresholds = np.linspace(.0, 100.0, n_thresh)
# symbol energy
Es = 1./mod_order
# noise variance
var_w = Es*sps.exp10(-snr_db/10.)
Pf = 1 - sps.gammainc(n_samples/2., thresholds/(2*var_w))
Pm = np.zeros(n_thresh)
printProgress(0, n_thresh, prefix='Progress', suffix='Complete', barLength=50)
if fading == 'exp_weibull':
beta, alpha, eta = args[0:3]
for k in range(n_thresh):
integrand = lambda u: (alpha*math.exp(-u)*(1 - math.exp(-u))**(alpha-1)) * (1 - marcumQ(math.sqrt(n_samples*Es*(eta*u**(1./beta))**2/var_w), math.sqrt(thresholds[k]/var_w), n_samples/2.0))
Pm[k] = quad(integrand, 0.0, np.inf, epsrel=1e-9, epsabs=0)[0]
printProgress(k, n_thresh-1, prefix='Progress', suffix='Complete', barLength=50)
elif fading == 'gamma_gamma':
beta, alpha = args[0:2]
for k in range(n_thresh):
integrand = lambda r: r**(0.5 * (alpha + beta)) * kv(alpha - beta, 2 * math.sqrt(alpha * beta * r)) * (1 - marcumQ(r * math.sqrt(n_samples * Es / var_w), np.sqrt(thresholds[k] / var_w), n_samples / 2.0))
Pm[k] = quad(integrand, 0.0, np.inf, epsrel=1e-9, epsabs=0)[0] * 2 * (alpha * beta)**(0.5 * (alpha + beta)) / (gamma(alpha) * gamma(beta))
printProgress(k, n_thresh-1, prefix='Progress', suffix='Complete', barLength=50)
return Pf, Pm
def constant_charge_single_energy(sigma0, r1, kappa, epsilon):
"""
It computes the total energy of a single sphere at constant charge,
inmmersed in water.
Arguments
----------
sigma0 : float, constant charge on the surface of the sphere.
r1 : float, radius of sphere.
kappa : float, reciprocal of Debye length.
epsilon: float, water dielectric constant.
Returns
--------
E : float, total energy.
"""
N = 20 # Number of terms in expansion
qe = 1.60217646e-19
Na = 6.0221415e23
E_0 = 8.854187818e-12
cal2J = 4.184
index2 = numpy.arange(N + 1, dtype=float) + 0.5
index = index2[0:-1]
K1 = special.kv(index2, kappa * r1)
K1p = index / (kappa * r1) * K1[0:-1] - K1[1:]
k1 = special.kv(index, kappa * r1) * numpy.sqrt(pi / (2 * kappa * r1))
k1p = -numpy.sqrt(pi / 2) * 1 / (2 * (kappa * r1)**(3 / 2.)) * special.kv(
index, kappa * r1) + numpy.sqrt(pi / (2 * kappa * r1)) * K1p
a0_inf = -sigma0 / (epsilon * kappa * k1p[0])
U1_inf = a0_inf * k1[0]
C1 = 2 * pi * sigma0 * r1 * r1
C0 = qe**2 * Na * 1e-3 * 1e10 / (cal2J * E_0)
E = C0 * C1 * U1_inf
return E
def WL_Q0_bT(self, bT):
return 1.0 * (
self.A / 2.0 / self.C * np.exp(-bT ** 2 / 4 / self.C)
- self.D
* 2 ** (1 - self.nu)
* self.M
* (bT * self.M) ** self.nu
* kv(1 - self.nu, bT * self.M)
/ bT
/ gamma(self.nu)
)
def _anisotropic_vonkarman_kernel(x, sigma, corr_length, g1, g2):
L = get_correlation_length_matrix(corr_length, g1, g2)
invL = np.linalg.inv(L)
dists = pdist(x, metric='mahalanobis', VI=invL)
K = dists **(5./6.) * special.kv(5./6., 2*np.pi * dists)
lim0 = special.gamma(5./6.) /(2 * ((np.pi)**(5./6.)) )
K = squareform(K)
np.fill_diagonal(K, lim0)
K /= lim0
K *= sigma**2
return K
