def GL(m, a, b):
points = p_roots(m)[0]
weights = p_roots(m)[1]
return (b - a) * sum([
weights[i] * f((b - a) * points[i] / 2 + (b + a) / 2)
for i in range(len(points))
]) / 2
def source_local(V, e, f, quad_degree=4):
B_e = np.zeros((V.N_loc))
c_basis = V.c_basis
vertices = V.mesh.vertices
dofmap = V.dofmap()
# Global coordinates for an element
x_map = c_basis[0].subs([(V.x_[i], vertices[dofmap(e, i)][0])
for i in range(V.N_loc)])
y_map = c_basis[1].subs([(V.y_[i], vertices[dofmap(e, i)][1])
for i in range(V.N_loc)])
# Local Jacobian of determinant
detJac_loc = V.Jac.det().subs([(V.x_[i], vertices[dofmap(e, i)][0])
for i in range(V.N_loc)])
detJac_loc = detJac_loc.subs([(V.y_[i], vertices[dofmap(e, i)][1])
for i in range(V.N_loc)])
# Use Gauss-Legendre quadrature
p, w = special.p_roots(quad_degree)
for i in range(V.N_loc):
for c_x in range(len(w)):
for c_y in range(len(w)):
B_e[i] += w[c_x] * w[c_y] * detJac_loc *\
(f(x_map, y_map) * V.basis[i])\
.subs([("xi", p[c_x]), ("eta", p[c_y])])
return B_e
def Gaussian_quadrature(n, lower_l, upper_l):
m = (upper_l - lower_l) / 2
c = (upper_l + lower_l) / 2
[x, w] = p_roots(n + 1)
weights = m * w
time_train_integral = m * x + c
return time_train_integral, weights
def __init__(self, *arg):
super(Frame2D, self).__init__(*arg)
self.n_intps = arg[3] if len(arg)>3 else 5
self.dim = 2
self.dof = 6
self.local_dof = 3 # 单元局部自由度
self.strain = np.zeros(self.local_dof)
# 计算积分点位置及权系数
xi,w = p_roots(self.n_intps)
xi = xi.real
self.loc_intps,self.wf_intps = 0.5*(xi+1.0),0.5*w
# 积分点的局部坐标
self.x = self.length*self.loc_intps
# 积分点截面序列
self.intps = []
# 积分点截面应变-位移转换矩阵序列
self.Bx = []
# 积分点截面轴向应变序列
self.epslnx = np.zeros(self.n_intps)
# 积分点截面曲率序列
self.kappax = np.zeros(self.n_intps)
# 遍历所有积分点
for i in xrange(self.n_intps):
self.intps.append(deepcopy(self.section))
xi = self.loc_intps[i]
self.Bx.append(spl.block_diag([1.],[6.*xi-4.,6.*xi-2]))
# 计算单元刚度
self.get_stiffness()
self.get_trans_matrix()
self.get_stiffness_matrix()
def __init__(self, *arg):
super(Frame2D, self).__init__(*arg)
self.n_intps = arg[3] if len(arg) > 3 else 5
self.dim = 2
self.dof = 6
self.local_dof = 3 # 单元局部自由度
self.strain = np.zeros(self.local_dof)
x, w = p_roots(self.n_intps)
x = x.real
self.loc_intps, self.wf_intps = 0.5 * (x + 1.0), 0.5 * w
self.x = self.length * self.loc_intps
self.intps = []
self.Dax = np.ones(self.n_intps)
self.Dbx = np.ones(self.n_intps)
for i in xrange(self.n_intps):
self.intps.append(deepcopy(self.section))
self.Dax[i] = self.intps[i].Da
self.Dbx[i] = self.intps[i].Db
self.kappax = np.zeros(self.n_intps)
self.get_stiffness()
self.get_trans_matrix()
self.get_stiffness_matrix()
def quest2b():
"Routine for answering question 2b"
E = 5.*np.arange(0,71) # in MeV
a = E[:-1] / 20.
b = E[1:]/20.
nodes = 10
F = 8*pi*np.power(20e6 * const.EV / (const.C*const.H),3)
n_i = np.array([])
[roots,weights] = spy.p_roots(nodes,0)
for k in xrange(0,len(a)):
n_i = np.append(n_i, 0.5*(b[k] - a[k])*sum(weights*funcb((b[k] - a[k])*roots/2. + (b[k] + a[k])/2.)))
Ex = E[:-1] + 2.5 # in Mev, centered bins
plt.clf()
fig1 = plt.figure(1)
plt.plot(Ex,F*n_i / 5.)
plt.xlabel('E (MeV)')
plt.ylabel('dn/dE ($cm^{-3} MeV^{-1}$)')
pp = PdfPages('ws3_prob2b.pdf')
pp.savefig(fig1)
pp.close()
return sum(n_i)*F
def A_local(V, e, quad_degree=4):
"""
Assemble the local stiffness matrix on element # e
"""
vertices = V.mesh.vertices
dofmap = V.dofmap()
A_e = np.zeros((V.N_loc, V.N_loc))
# Local Jacobian of determinant
detJac_loc = V.Jac.det().subs([(V.x_[i], vertices[dofmap(e, i)][0])
for i in range(V.N_loc)])
detJac_loc = detJac_loc.subs([(V.y_[i], vertices[dofmap(e, i)][1])
for i in range(V.N_loc)])
# Local Jacobian
Jac_loc = V.Jac.subs([(V.x_[i], vertices[dofmap(e, i)][0])
for i in range(V.N_loc)])
Jac_loc = Jac_loc.subs([(V.y_[i], vertices[dofmap(e, i)][1])
for i in range(V.N_loc)])
p, w = special.p_roots(quad_degree)
for i in range(V.N_loc):
for j in range(V.N_loc):
# Looping over quadrature points on ref element
for c_x in range(len(w)):
for c_y in range(len(w)):
# Stiffness Matrix
Jac_loc = Jac_loc.subs([("xi", p[c_x]), ("eta", p[c_y])])
gradgrad = (sp.transpose(Jac_loc.inv() * V.grads[j]) *
Jac_loc.inv() * V.grads[i])
integrand = w[c_x] * w[c_y] * gradgrad * detJac_loc
A_e[i, j] += integrand.subs([("xi", p[c_x]),
("eta", p[c_y])])[0, 0]
return A_e
def leg(n, a, b): [legroots, legweights] = sp.p_roots(n,0) integ = 0.0 for i in range(0, n): troot = ((b-a)*legroots[i]+(a+b))/2.0 integ += legweights[i]*f(troot) return integ*(b-a)/2.0
def get_trial_derivative_L2(self, expected):
# Get the L2 norm error for the given expected function vs FEM results
integral = 0
for i in self.elements.keys():
xi = sy.symbols('xi')
expr_exp = sy.sympify(expected)
expr_approx = self.elements[i].trial_prime
expr_error = (expr_exp - expr_approx) ** 2
domain = [self.elements[i].start, self.elements[i].end]
order = sy.degree(expr_error, x)
length = domain[-1] - domain[0]
npg = ceil((order + 1) / 2)
new_x = (0.5 * (domain[0] + domain[1])
+ 0.5 * xi * (domain[1] - domain[0]))
expr = expr_error.subs(x, new_x)
[new_xi, w] = p_roots(npg)
for j in range(len(new_xi)):
integral = (integral
+ (w[j] * length * 0.5 * expr.subs(xi,
new_xi[j]))
)
print(integral)
self.L2_error = integral
def twob(): n=20 #matches the n=20 used for highest accuracy in part a) deltaE=5 #MeV kT=3.2*10**(-5) #cgs hc=3.16*10**(-17) #cgs #use Python's built-in Gauss-Legendre roots and weights [le_r,le_w]=sp.p_roots(n) #define the substitution I made x=lambda u,i:(5.*u+10.*i+5.)/(2.) #and f(x) f=lambda u,i:(x(u,i))**2/(np.exp(x(u,i))+1) ne=np.zeros(150./5.)#array of n_e for each energy bin Q=np.zeros(len(le_r)) #loop over each energy bin for i in range(len(ne)): #and calculate n_e in each bin for j in range(len(Q)): Q[j]=le_w[j]*f(le_r[j],i) Qtot=np.sum(Q) ne[i]=5./2.*(Qtot*8.*np.pi*(kT)**3)/(2.*np.pi*hc)**3 dndE=ne/deltaE #print the result print dndE #and check if the total n_e matches part a) print np.sum(dndE)*deltaE
def Gaussian_quadrature(self, n, lower_l, upper_l):
m = (upper_l-lower_l)/2
c = (upper_l+lower_l)/2
[x,w] = p_roots(n+1)
self.weights = w*m
# self.weights = torch.tensor(self.weights).type('torch.FloatTensor')
self.time_train_integral = m*x+c
return [self.time_train_integral, self.weights]
def _cached_roots_legendre(n):
"""
Cache roots_legendre results to speed up calls of the fixed_quad
function.
"""
if n in _cached_roots_legendre.cache:
return _cached_roots_legendre.cache[n]
_cached_roots_legendre.cache[n] = p_roots(n)
return _cached_roots_legendre.cache[n]
def get_psi_sq(self):
"""
Calculate the term <psii,psij>
Returns
-------
psi_sq : array
the term <psii,psij>
"""
dim = self.my_experiment.dimension
multindices = self.basis['multi-indices']
n_terms = len(multindices)
psi_sq = np.ones(n_terms, )
for i in range(n_terms):
for j in range(dim):
deg = multindices[i][j]
if self.my_experiment.polytypes[j] == 'Legendre':
x_i, w_i = special.p_roots(deg + 1)
'''
Integrate exactly the SQUARE
of the Legendre polynomial. For example,
if the Legendre polynomial is of order (deg),
the numerical integration must be exact
till order (deg**2). Thus, we need at least
(deg+1) abscissas' and weights.
'''
poly = special.legendre(deg)**2
psi_sq[i] *= 1.0 / 2 * sum(w_i * poly(x_i))
elif self.my_experiment.polytypes[j] == 'Hermite':
x_i, w_i = special.he_roots(deg + 1)
'''
special.he_roots(deg) and
np.polynomial.hermite_e.hermegauss(deg)
returns the same abscissas'
but different weights (!). There is a factor 2
between the two. Given the fact that the integral of
the standard Gaussian must be 1,
np.polynomial.hermite_e.hermegauss(deg)
provides the right weights.
'''
poly = special.hermitenorm(deg)**2
# 2*w_i*poly(x_i)
psi_sq[i] *= 1.0 / np.sqrt(2 * np.pi) * sum(
w_i * poly(x_i))
return psi_sq
def gle(n, a, b):
[leg_roots, leg_weights] = sp.p_roots(n,0)
# Once again, I abandon the for loop
# total = 0
# for i in range(n):
# total += leg_weights[i] * g(((b-a)/2)*leg_roots[i] + ((a+b)/2))
# return total
func_vals = g(((b-a)/2)*leg_roots + ((a+b)/2))
return np.dot(leg_weights, func_vals)
def gausslegendre(f, a, b, n):
# uses roots of legendre polynomials
x, w = p_roots(n)
psum = 0
# valid only over interval [-1,1]
# map input [a,b] to interval [-1,1]
for i in range(n):
# transform interval
psum += w[i] * f(0.5 * (b - a) * x[i] + 0.5 * (b + a))
gaus = 0.5 * (b - a) * psum
return gaus
def gausslegendre(f,a,b,n):
# uses roots of legendre polynomials
x,w = p_roots(n)
psum = 0
# valid only over interval [-1,1]
# map input [a,b] to interval [-1,1]
for i in range(n):
# transform interval
psum += w[i]*f(0.5*(b-a)*x[i] + 0.5*(b+a))
gaus = 0.5*(b-a)*psum
return gaus
def _sk_integral_fixed_quad(k, y, Nquad):
# Get numerical quadrature nodes and weight
nodes, weights = p_roots(Nquad)
# Rescale for integration interval from [-1,1] to [-pi,pi]
nodes = nodes * np.pi
weights = weights * 0.5
arg1 = 2 * k * (1 + y * np.cos(nodes)) / 3
arg2 = k * nodes + 4 * k * y * np.sin(nodes) / 3
integrand = k0(arg1) * np.cos(arg2)
return (2 / np.pi) * integrand @ weights
def GaussianQuadrature():
########## PART A ##########
# Array to carry integrands
n = 30
intArr = np.zeros(n,)
# Loop over all numbers of nodes
intFact = FD_factor(20.) # kT = 20MeV
for i in range(1,n+1):
# Find roots and approximate integral
[xi,wi] = sp.l_roots(i)
intArr[i-1] = intFact*np.sum(wi*fermi_dirac_mod(xi))
# Save integral array to file
np.savetxt('Q2_numdensity.dat',intArr,fmt='%10.10e')
############################
########## PART B ##########
# nInt-1 intervals of width dE = 5MeV
# in range [0,150] MeV
nInt = 30
dE = 5.
dndE = np.zeros(nInt,)
# Find roots
[xi,wi] = sp.p_roots(n)
# Transformations for xi,wi in each interval
xTemp = np.linspace(0.,150.,num=nInt+1)
bMa = 2.5 # b-a/2
bPa = 0.5*(xTemp[1:] + xTemp[:-1]) # b+a/2
# Loop over all intervals
for i in range(0,nInt):
# Transform variables
w = wi*bMa
x = bMa*xi + bPa[i]
# Evaluate intgral and differential
dndE[i] = (intFact/dE)*np.sum(w*fermi_dirac(x))
# Save spectral information to file
outArr1 = np.zeros((nInt,2.),float)
outArr1[:,0] = bPa
outArr1[:,1] = dndE
np.savetxt('Q2_energyspectrum.dat',outArr1,fmt='%10.10e')
# Verify method and save to file
outArr2 = [intArr[-1],np.sum(dndE*dE)]
np.savetxt('Q2_verifymethod.dat',outArr2,fmt='%10.10e')
############################
return
def gaussLegendre(g, a, b, n):
f = lambda x: eval(g) # define function to evaluate
# get abscissas (xi), and weights (wi) from p_roots(n) function below
# scipy.special.p_roots(n) returns abscissas & weights of Legendre polynomials
abscissa, weight = p_roots(n)
intSum = 0
# Gauss-Legendre method is valid only over interval [-1,1]
# map input [a,b] to interval [-1,1]
for i in range(n):
# evaluate integral with interval transformed by x--> 0.5(b-a)x + 0.5(b+a)
intSum = intSum + weight[i]*f(0.5*(b-a)*abscissa[i] + 0.5*(b+a))
return 0.5*(b-a)*intSum
def volume_local(V, e, coeffs, quad_degree=4):
dofmap = V.dofmap()
# Local Jacobian of determinant
detJac_loc = V.Jac.det().subs([(V.x_[i], V.mesh.vertices[dofmap(e, i)][0])
for i in range(V.N_loc)])
detJac_loc = detJac_loc.subs([(V.y_[i], V.mesh.vertices[dofmap(e, i)][1])
for i in range(V.N_loc)])
p, w = special.p_roots(quad_degree)
loc = 0
for i in range(V.N_loc):
for c_x in range(len(w)):
for c_y in range(len(w)):
loc += w[c_x] * w[c_y] *\
(detJac_loc * ((coeffs[dofmap(e, i)] * V.basis[i]))
.subs([("xi", p[c_x]), ("eta", p[c_y])]))
return loc
def gauss_legendre(f, a, b, n):
[roots,weights] = sp.p_roots(n,0)
return (b-a)/2.*sum([weights[i]*f((b-a)/2.*roots[i]+(a+b)/2.) for i in range(n)])
def gauss_legendre(f,n,a,b):
[legendre_roots, legendre_weights] = sp.p_roots(n,0)
trans = float(b-a)/2
return trans * sum( \
f(legendre_roots * trans + float(a+b)/2) * legendre_weights )
# # E -- FFT # #
# Signal = 0
_, f, _, ftarg = utils.check_time(t, 0, 'fft', [0.0005, 2**20, '', 10], 0)
fEM = test_freq(res, off, f)
fft0 = {'fEM': fEM, 'f': f, 'ftarg': ftarg}
# # F -- QWE - FQWE # #
nquad = fqwe0['ftarg'][2]
maxint = fqwe0['ftarg'][3]
fEM = fqwe0['fEM']
freq = fqwe0['f']
# The following is a condensed version of transform.fqwe, without doqwe-part
xint = np.concatenate((np.array([1e-20]), np.arange(1, maxint + 1) * np.pi))
intervals = xint / t[:, None]
g_x, g_w = special.p_roots(nquad)
dx = np.repeat(np.diff(xint) / 2, nquad)
Bx = dx * (np.tile(g_x, maxint) + 1) + np.repeat(xint[:-1], nquad)
SS = np.sin(Bx) * np.tile(g_w, maxint)
tEM_iint = iuSpline(np.log(2 * np.pi * freq), fEM.imag)
sEM = tEM_iint(np.log(Bx / t[:, None])) * SS
fqwe0['sEM'] = sEM
fqwe0['intervals'] = intervals
# # G -- QWE - HQWE # #
# Model
model = utils.check_model([], 10, 2, 2, 5, 1, 10, True, 0)
depth, res, aniso, epermH, epermV, mpermH, mpermV, isfullspace = model
frequency = utils.check_frequency(1, res, aniso, epermH, epermV, mpermH,
mpermV, 0)
freq, etaH, etaV, zetaH, zetaV = frequency
from numpy import *
from scipy import special as sp
[legendre_roots,legendre_weights]=sp.p_roots(2,0)
#create intervals dE=5
t= linspace(0,150, 31.)
#from Wolfram Alpha
k=20#in 1/MeV
h=1.97327*10**-11 #in Mev cm
#define our integrad with change of variables
def f(x,n):
return 2.5*(2.5*x+.5*(t[int(n)]+t[int(n+1)]))**2./(exp(.05*(2.5*x+.5*(t[int(n)]+t[int(n+1)])))+1)
#convert to 31xn dimensional array whose ith element is the ith integral in (0,150,31)
z=[]
for i in linspace(0,29,30):
z.extend([f(legendre_roots,i)])
#sum over rows and columns
b1=sum(z,axis=0)
c1=sum(b1,axis=0)
print sum(legendre_weights*b1)
def build_mesh(self):
N, E = self.N, self.E
L = self.L
periodic = self.periodic
n = N + 1
n_dofs = N * E
if not periodic:
n_dofs += 1
self.n_dofs = n_dofs
semh = SEMhat(N)
vertices = np.linspace(0, L, E + 1)
etv = np.zeros((E, 2), dtype=np.int)
etv[:, 0] = np.arange(E)
etv[:, 1] = np.arange(E) + 1
topo = Interval()
xq = topo.ref_to_phys(vertices[etv], semh.xgll)
if periodic:
xq = xq[:, :-1]
self.xq = xq
jacb_det = topo.calc_jacb(vertices[etv])[0]
self.jacb_det = jacb_det
if periodic:
etv[0, 0] = etv[-1, -1]
# Make 1D elem to dof map
etd = np.arange(E * (N + 1))
etd = etd.reshape((E, -1))
etd -= np.arange(E)[:, newaxis]
if periodic:
etd[-1, -1] = etd[0, 0]
# Make Q
cols = etd.ravel()
rows = np.arange(len(cols))
vals = np.ones(len(cols))
Q0 = sps.coo_matrix((vals, (rows, cols)), dtype=np.int)
Q = kron3(Q0, Q0, Q0)
self.Q = Q
self.Q0 = Q0
# Build etd for full mesh
nd = E * (N + 1)
dofs = Q.dot(np.arange(Q.shape[1])).reshape((nd, nd, nd))
etd = np.zeros((E**3, n**3), dtype=np.int)
ind = 0
for iz in range(E):
for iy in range(E):
for ix in range(E):
a = dofs[iz * n:iz * n + n, iy * n:iy * n + n,
ix * n:ix * n + n]
etd[ind, :] = a.ravel()
ind += 1
self.etd = etd
dofs = None
# Q for assembly. NOT the tensor product Q.
cols = etd.ravel()
rows = np.arange(len(cols))
vals = np.ones(len(cols))
QA = sps.coo_matrix((vals, (rows, cols)), dtype=np.int)
self.QA = QA
# Make R
if periodic:
R0 = sps.eye(n_dofs)
else:
R0 = sps.dia_matrix((np.ones(n_dofs), 1),
shape=(n_dofs - 2, n_dofs))
R = kron3(R0, R0, R0)
self.R = R
if (not periodic):
dofs = np.arange(n_dofs**3)
bndy_dofs = list(set(dofs) - set(R.dot(dofs)))
bndy_dofs = np.array(bndy_dofs, dtype=np.int)
self.bndy_dofs = bndy_dofs
dofs = None
## Build A and B
Al = sps.kron(sps.eye(E), semh.Ah / jacb_det)
A0 = Q0.T.dot(Al.dot(Q0))
A0 = R0.dot(A0.dot(R0.T))
Ah0 = semh.Ah / jacb_det
# Full local mass matrix
xgll, wgll = gll_points(n)
xg, wg = p_roots(n)
L = eval_phi1d(xgll, xg).T
Bf = sps.dia_matrix((wg, 0), shape=(n, n))
Bf = L.T.dot(Bf.dot(L))
# Bl0 = sps.kron(sps.eye(E), semh.Bh*jacb_det)
Bl0 = sps.kron(sps.eye(E), Bf * jacb_det)
B0 = Q0.T.dot(Bl0.dot(Q0))
B0 = R0.dot(B0.dot(R0.T))
Bh0 = Bf * jacb_det
Bh = kron3(Bh0, Bh0, Bh0).toarray()
self.Bh = Bh
Ah = kron3(Bh0, Bh0, Ah0)
Ah += kron3(Bh0, Ah0, Bh0)
Ah += kron3(Ah0, Bh0, Bh0)
self.Ah = Ah.toarray()
# Bh = kron3(Bh0, Bh0, Bh0)
# self.Bh = Bh
eigvals, eigvecs = scipy.linalg.eigh(A0.toarray(), B0.toarray())
self.eigvals, self.eigvecs = eigvals, eigvecs
n_eigs = len(eigvals)
L = sps.dia_matrix((eigvals, 0), shape=(n_eigs, n_eigs))
eye = sps.eye(n_eigs)
C1 = kron3(eye, eye, L) + kron3(eye, L, eye) + kron3(L, eye, eye)
is_zero = np.abs(C1.data) < 1e-12
C1.data[is_zero] = 1.0
C1.data = 1.0 / C1.data
C1.data[is_zero] = 0.0
self.C1 = C1
def check_legendre_roots(n):
xs, ws = ([], []) if n == 0 else p_roots(n) # from SciPy
xl, wl = libsharp.legendre_roots(n)
assert_allclose(xs, xl)
assert_allclose(ws, wl)
def hqwe(zsrc, zrec, lsrc, lrec, off, factAng, depth, ab, etaH, etaV, zetaH,
zetaV, xdirect, qweargs, use_ne_eval, msrc, mrec):
r"""Hankel Transform using Quadrature-With-Extrapolation.
*Quadrature-With-Extrapolation* was introduced to geophysics by
[Key12]_. It is one of many so-called *ISE* methods to solve Hankel
Transforms, where *ISE* stands for Integration, Summation, and
Extrapolation.
Following [Key12]_, but without going into the mathematical details here,
the QWE method rewrites the Hankel transform of the form
.. math:: F(r) = \int^\infty_0 f(\lambda)J_v(\lambda r)\
\mathrm{d}\lambda
as a quadrature sum which form is similar to the DLF (equation 15),
.. math:: F_i \approx \sum^m_{j=1} f(x_j/r)w_j g(x_j) =
\sum^m_{j=1} f(x_j/r)\hat{g}(x_j) \ ,
but with various bells and whistles applied (using the so-called Shanks
transformation in the form of a routine called :math:`\epsilon`-algorithm
([Shan55]_, [Wynn56]_; implemented with algorithms from [Tref00]_ and
[Weni89]_).
This function is based on ``get_CSEM1D_FD_QWE.m``, ``qwe.m``, and
``getBesselWeights.m`` from the source code distributed with [Key12]_.
In the spline-version, ``hqwe`` checks how steep the decay of the
wavenumber-domain result is, and calls QUAD for the very steep interval,
for which QWE is not suited.
The function is called from one of the modelling routines in :mod:`model`.
Consult these modelling routines for a description of the input and output
parameters.
Returns
-------
fEM : array
Returns frequency-domain EM response.
kcount : int
Kernel count.
conv : bool
If true, QWE/QUAD converged. If not, <htarg> might have to be adjusted.
"""
# Input params have an additional dimension for frequency, reduce here
etaH = etaH[0, :]
etaV = etaV[0, :]
zetaH = zetaH[0, :]
zetaV = zetaV[0, :]
# Get rtol, atol, nquad, maxint, and pts_per_dec
rtol, atol, nquad, maxint, pts_per_dec = qweargs[:5]
# 1. PRE-COMPUTE THE BESSEL FUNCTIONS
# at fixed quadrature points for each interval and multiply by the
# corresponding Gauss quadrature weights
# Get Gauss quadrature weights
g_x, g_w = special.p_roots(nquad)
# Compute n zeros of the Bessel function of the first kind of order 1 using
# the Newton-Raphson method, which is fast enough for our purposes. Could
# be done with a loop for (but it is slower):
# b_zero[i] = optimize.newton(special.j1, b_zero[i])
# Initial guess using asymptotic zeros
b_zero = np.pi * np.arange(1.25, maxint + 1)
# Newton-Raphson iterations
for i in range(10): # 10 is more than enough, usually stops in 5
# Evaluate
b_x0 = special.j1(b_zero) # j0 and j1 have faster versions
b_x1 = special.jv(2, b_zero) # j2 does not have a faster version
# The step length
b_h = -b_x0 / (b_x0 / b_zero - b_x1)
# Take the step
b_zero += b_h
# Check for convergence
if all(np.abs(b_h) < 8 * np.finfo(float).eps * b_zero):
break
# 2. COMPUTE THE QUADRATURE INTERVALS AND BESSEL FUNCTION WEIGHTS
# Lower limit of integrand, a small but non-zero value
xint = np.concatenate((np.array([1e-20]), b_zero))
# Assemble the output arrays
dx = np.repeat(np.diff(xint) / 2, nquad)
Bx = dx * (np.tile(g_x, maxint) + 1) + np.repeat(xint[:-1], nquad)
BJ0 = special.j0(Bx) * np.tile(g_w, maxint)
BJ1 = special.j1(Bx) * np.tile(g_w, maxint)
# 3. START QWE
# Intervals and lambdas for all offset
intervals = xint / off[:, None]
lambd = Bx / off[:, None]
# The following lines until
# "Call and return QWE, depending if spline or not"
# are part of the splined routine. However, we calculate it here to get
# the non-zero kernels, `k_used`.
# New lambda, from min to max required lambda with pts_per_dec
start = np.log10(lambd.min())
stop = np.log10(lambd.max())
# If not spline, we just calculate three lambdas to check
if pts_per_dec == 0:
ilambd = np.logspace(start, stop, 3)
else:
ilambd = np.logspace(start, stop, (stop - start) * pts_per_dec + 1)
# Call the kernel
PJ0, PJ1, PJ0b = kernel.wavenumber(zsrc, zrec, lsrc, lrec, depth,
etaH[None, :], etaV[None, :],
zetaH[None, :], zetaV[None, :],
np.atleast_2d(ilambd), ab, xdirect,
msrc, mrec, use_ne_eval)
# Check which kernels have information
k_used = [True, True, True]
for i, val in enumerate((PJ0, PJ1, PJ0b)):
if val is None:
k_used[i] = False
# Call and return QWE, depending if spline or not
if pts_per_dec != 0: # If spline, we calculate all kernels here
# Interpolation : Has to be done separately on each PJ,
# in order to work with multiple offsets which have different angles.
if k_used[0]:
sPJ0r = iuSpline(np.log(ilambd), PJ0.real)
sPJ0i = iuSpline(np.log(ilambd), PJ0.imag)
else:
sPJ0r = None
sPJ0i = None
if k_used[1]:
sPJ1r = iuSpline(np.log(ilambd), PJ1.real)
sPJ1i = iuSpline(np.log(ilambd), PJ1.imag)
else:
sPJ1r = None
sPJ1i = None
if k_used[2]:
sPJ0br = iuSpline(np.log(ilambd), PJ0b.real)
sPJ0bi = iuSpline(np.log(ilambd), PJ0b.imag)
else:
sPJ0br = None
sPJ0bi = None
# Get quadargs: diff_quad, a, b, limit
diff_quad, a, b, limit = qweargs[5:]
# Set quadargs if not given:
if not limit:
limit = maxint
if not a:
a = intervals[:, 0]
else:
a = a * np.ones(off.shape)
if not b:
b = intervals[:, -1]
else:
b = b * np.ones(off.shape)
# Check if we use QWE or SciPy's QUAD
# If there are any steep decays within an interval we have to use QUAD,
# as QWE is not designed for these intervals.
check0 = np.log(intervals[:, :-1])
check1 = np.log(intervals[:, 1:])
numerator = np.zeros((off.size, maxint), dtype=complex)
denominator = np.zeros((off.size, maxint), dtype=complex)
if k_used[0]:
numerator += sPJ0r(check0) + 1j * sPJ0i(check0)
denominator += sPJ0r(check1) + 1j * sPJ0i(check1)
if k_used[1]:
numerator += sPJ1r(check0) + 1j * sPJ1i(check0)
denominator += sPJ1r(check1) + 1j * sPJ1i(check1)
if k_used[2]:
numerator += sPJ0br(check0) + 1j * sPJ0bi(check0)
denominator += sPJ0br(check1) + 1j * sPJ0bi(check1)
doqwe = np.all((np.abs(numerator) / np.abs(denominator) < diff_quad),
1)
# Pre-allocate output array
fEM = np.zeros(off.size, dtype=complex)
conv = True
# Carry out SciPy's Quad if required
if np.any(~doqwe):
# Loop over offsets that require Quad
for i in np.where(~doqwe)[0]:
# Input-dictionary for quad
iinp = {
'a': a[i],
'b': b[i],
'epsabs': atol,
'epsrel': rtol,
'limit': limit
}
fEM[i], tc = quad(sPJ0r, sPJ0i, sPJ1r, sPJ1i, sPJ0br, sPJ0bi,
ab, off[i], factAng[i], iinp)
# Update conv
conv *= tc
# Return kcount=1 in case no QWE is calculated
kcount = 1
if np.any(doqwe):
# Get EM-field at required offsets
if k_used[0]:
sPJ0 = sPJ0r(np.log(lambd)) + 1j * sPJ0i(np.log(lambd))
if k_used[1]:
sPJ1 = sPJ1r(np.log(lambd)) + 1j * sPJ1i(np.log(lambd))
if k_used[2]:
sPJ0b = sPJ0br(np.log(lambd)) + 1j * sPJ0bi(np.log(lambd))
# Carry out and return the Hankel transform for this interval
sEM = np.zeros_like(numerator, dtype=complex)
if k_used[1]:
sEM += np.sum(
np.reshape(sPJ1 * BJ1, (off.size, nquad, -1), order='F'),
1)
if ab in [11, 12, 21, 22, 14, 24, 15, 25]: # Because of J2
# J2(kr) = 2/(kr)*J1(kr) - J0(kr)
sEM /= np.atleast_1d(off[:, np.newaxis])
if k_used[2]:
sEM += np.sum(
np.reshape(sPJ0b * BJ0, (off.size, nquad, -1), order='F'),
1)
if k_used[1] or k_used[2]:
sEM *= factAng[:, np.newaxis]
if k_used[0]:
sEM += np.sum(
np.reshape(sPJ0 * BJ0, (off.size, nquad, -1), order='F'),
1)
getkernel = sEM[doqwe, :]
# Get QWE
fEM[doqwe], kcount, tc = qwe(rtol, atol, maxint, getkernel,
intervals[doqwe, :], None, None, None)
conv *= tc
else: # If not spline, we define the wavenumber-kernel here
def getkernel(i, inplambd, inpoff, inpfang):
r"""Return wavenumber-domain-kernel as a fct of interval i."""
# Indices and factor for this interval
iB = i * nquad + np.arange(nquad)
# PJ0 and PJ1 for this interval
PJ0, PJ1, PJ0b = kernel.wavenumber(zsrc, zrec, lsrc, lrec, depth,
etaH[None, :], etaV[None, :],
zetaH[None, :], zetaV[None, :],
np.atleast_2d(inplambd)[:, iB],
ab, xdirect, msrc, mrec,
use_ne_eval)
# Carry out and return the Hankel transform for this interval
gEM = np.zeros_like(inpoff, dtype=complex)
if k_used[1]:
gEM += inpfang * np.dot(PJ1[0, :], BJ1[iB])
if ab in [11, 12, 21, 22, 14, 24, 15, 25]: # Because of J2
# J2(kr) = 2/(kr)*J1(kr) - J0(kr)
gEM /= np.atleast_1d(inpoff)
if k_used[2]:
gEM += inpfang * np.dot(PJ0b[0, :], BJ0[iB])
if k_used[0]:
gEM += np.dot(PJ0[0, :], BJ0[iB])
return gEM
# Get QWE
fEM, kcount, conv = qwe(rtol, atol, maxint, getkernel, intervals,
lambd, off, factAng)
return fEM, kcount, conv
def fqwe(fEM, time, freq, qweargs):
r"""Fourier Transform using Quadrature-With-Extrapolation.
It follows the QWE methodology [Key12]_ for the Hankel transform, see
``hqwe`` for more information.
The function is called from one of the modelling routines in :mod:`model`.
Consult these modelling routines for a description of the input and output
parameters.
This function is based on ``get_CSEM1D_TD_QWE.m`` from the source code
distributed with [Key12]_.
``fqwe`` checks how steep the decay of the frequency-domain result is, and
calls QUAD for the very steep interval, for which QWE is not suited.
Returns
-------
tEM : array
Returns time-domain EM response of ``fEM`` for given ``time``.
conv : bool
If true, QWE/QUAD converged. If not, <ftarg> might have to be adjusted.
"""
# Get rtol, atol, nquad, maxint, diff_quad, a, b, and limit
rtol, atol, nquad, maxint, _, diff_quad, a, b, limit, sincos = qweargs
# Calculate quadrature intervals for all offset
xint = np.concatenate(
(np.array([1e-20]), np.arange(1, maxint + 1) * np.pi))
if sincos == np.cos: # Adjust zero-crossings if cosine-transform
xint[1:] -= np.pi / 2
intervals = xint / time[:, None]
# Get Gauss Quadrature Weights
g_x, g_w = special.p_roots(nquad)
# Pre-compute the Bessel functions at fixed quadrature points, multiplied
# by the corresponding Gauss quadrature weight.
dx = np.repeat(np.diff(xint) / 2, nquad)
Bx = dx * (np.tile(g_x, maxint) + 1) + np.repeat(xint[:-1], nquad)
SS = sincos(Bx) * np.tile(g_w, maxint)
# Interpolate in frequency domain
tEM_rint = iuSpline(np.log(2 * np.pi * freq), fEM.real)
tEM_iint = iuSpline(np.log(2 * np.pi * freq), -fEM.imag)
# Check if we use QWE or SciPy's QUAD
# If there are any steep decays within an interval we have to use QUAD, as
# QWE is not designed for these intervals.
check0 = np.log(intervals[:, :-1])
check1 = np.log(intervals[:, 1:])
doqwe = np.all(
(np.abs(tEM_rint(check0) + 1j * tEM_iint(check0)) /
np.abs(tEM_rint(check1) + 1j * tEM_iint(check1)) < diff_quad), 1)
# Choose imaginary part if sine-transform, else real part
if sincos == np.sin:
tEM_int = tEM_iint
else:
tEM_int = tEM_rint
# Set quadargs if not given:
if not limit:
limit = maxint
if not a:
a = intervals[:, 0]
else:
a = a * np.ones(time.shape)
if not b:
b = intervals[:, -1]
else:
b = b * np.ones(time.shape)
# Pre-allocate output array
tEM = np.zeros(time.size)
conv = True
# Carry out SciPy's Quad if required
if np.any(~doqwe):
def sEMquad(w, t):
r"""Return scaled, interpolated value of tEM_int for ``w``."""
return tEM_int(np.log(w)) * sincos(w * t)
# Loop over times that require QUAD
for i in np.where(~doqwe)[0]:
out = integrate.quad(sEMquad, a[i], b[i], (time[i], ), 1, atol,
rtol, limit)
tEM[i] = out[0]
# If there is a fourth output from QUAD, it means it did not conv.
if len(out) > 3:
conv *= False
# Carry out QWE for 'well-behaved' intervals
if np.any(doqwe):
sEM = tEM_int(np.log(Bx / time[doqwe, None])) * SS
tEM[doqwe], _, tc = qwe(rtol, atol, maxint, sEM, intervals[doqwe, :])
conv *= tc
return tEM, conv
# parameters
n = 100 # number of nodes in Legendre Quadrature
dE = 5 # energy bin size (MeV)
max_E = 155 # energy cutoff (MeV)
Es = np.arange(0, 155, dE) # energies
xs = Es / 20.0 # x parameter, energy / temperature (20 MeV)
def x(y, a, b):
return 0.5 * (y + 1) * (b - a) + a
def f(y, a, b):
x_ = x(y, a, b)
return 0.5 * (b - a) * x_ * x_ / (np.exp(x_) + 1)
[ys, ws] = sp.p_roots(n, 0)
Qs = np.array([np.sum(ws * f(ys, xs[i], xs[i+1])) for i in range(len(xs) - 1)])
print("\nPart B\n")
print("Total number density: {}".format(number_density_coeff * np.sum(Qs)))
myfig = pl.figure(figsize=(10,8))
myfig.subplots_adjust(left=0.13)
myfig.subplots_adjust(bottom=0.14)
myfig.subplots_adjust(top=0.90)
myfig.subplots_adjust(right=0.95)
pl.bar(Es[:-1], number_density_coeff * Qs / 10**34, color='c', width=5)
pl.xlim(0, max_E - dE)
pl.xlabel("Energy bin [MeV]")
pl.ylabel(r"Number density [$\times 10^{34}$ cm$^{-3}$]")
def GaussLegendre(func, a, b, n):
[legendre_roots, legendre_weights] = sp.p_roots(n, 0.)
return np.sum(legendre_weights*(b-a)*func((b-a)*
legendre_roots/2.+(a+b)/2.)/2.)
import numpy as np
from scipy import special as sp
def g(x):
return (x**2)/(1.0+np.exp(x/20.0))
energy=np.arange(0,155,5)
interval=len(energy)-1
integrate=np.zeros(interval)
for i in np.arange(interval):
a=energy[i]; b=energy[i+1];
roots,weights=sp.p_roots(10);
x=a+0.5*(b-a)*(roots+1);
integrate[i]=np.sum(weights*0.5*(b-a)*g(x))
print "i","E_i","n_i","n_i/dE"
for i in np.arange(interval):
print i+1,energy[i],integrate[i],integrate[i]/5.
def check_spectrum(pyrat):
"""
Check that user input arguments make sense.
"""
# Shortcuts:
log = pyrat.log
phy = pyrat.phy
spec = pyrat.spec
atm = pyrat.atm
obs = pyrat.obs
# Check that input files exist:
if pyrat.mol.molfile is None:
pyrat.mol.molfile = pc.ROOT + 'pyratbay/data/molecules.dat'
with pt.log_error(log):
pt.file_exists('atmfile', 'Atmospheric', pyrat.atm.atmfile)
pt.file_exists('tlifile', 'TLI', pyrat.lt.tlifile)
pt.file_exists('molfile', 'Molecular-data', pyrat.mol.molfile)
if pyrat.runmode == 'spectrum' and spec.specfile is None:
log.error('Undefined output spectrum file (specfile).')
# Compute the Hill radius for the planet:
if (phy.mstar is not None and phy.mplanet is not None
and phy.smaxis is not None):
phy.rhill = phy.smaxis * (phy.mplanet / (3 * phy.mstar))**(1.0 / 3.0)
# Check Voigt-profile arguments:
if (pyrat.voigt.dmin is not None and pyrat.voigt.dmax is not None
and pyrat.voigt.dmax <= pyrat.voigt.dmin):
log.error('dmax ({:g} cm-1) must be > dmin ({:g} cm-1).'.format(
pyrat.voigt.dmax, pyrat.voigt.dmin))
if (pyrat.voigt.lmin is not None and pyrat.voigt.lmax is not None
and pyrat.voigt.lmax <= pyrat.voigt.lmin):
log.error('lmax ({:g} cm-1) must be > lmin ({:g} cm-1).'.format(
pyrat.voigt.lmax, pyrat.voigt.lmin))
if pyrat.runmode == 'opacity' or pt.isfile(pyrat.ex.extfile) == 0:
if pyrat.ex.tmin is None:
log.error('Undefined lower temperature boundary (tmin) for '
'extinction-coefficient grid.')
if pyrat.ex.tmax is None:
log.error('Undefined upper temperature boundary (tmax) for '
'extinction-coefficient grid.')
if pyrat.ex.tstep is None:
log.error('Undefined temperature sampling step (tstep) for '
'extinction-coefficient grid.')
if pyrat.lt.tlifile is None:
log.error('Requested extinction-coefficient table, but there '
'are no input TLI files.')
if pyrat.runmode == 'mcmc':
if pyrat.od.rt_path in pc.emission_rt:
if pyrat.phy.rplanet is None or pyrat.phy.rstar is None:
log.error("Undefined radius ratio (need rplanet and rstar).")
if pyrat.obs.data is None:
log.error("Undefined transit/eclipse data (data).")
if pyrat.obs.uncert is None:
log.error("Undefined data uncertainties (uncert).")
if pyrat.obs.filters is None:
log.error("Undefined transmission filters (filters).")
if pyrat.ret.retflag == []:
log.error(
'Undefined retrieval model flags. Select from {}.'.format(
pc.retflags))
if pyrat.ret.sampler is None:
log.error('Undefined retrieval algorithm (sampler). Select from '
'[snooker].')
if pyrat.ret.nsamples is None:
log.error('Undefined number of retrieval samples (nsamples).')
if pyrat.ret.burnin is None:
log.error(
'Undefined number of retrieval burn-in samples (burnin).')
if pyrat.ret.nchains is None:
log.error(
'Undefined number of retrieval parallel chains (nchains).')
if pyrat.ret.params is None:
log.error('Undefined retrieval fitting parameters (params).')
# Check cloud models:
if pyrat.cloud.model_names is not None:
pyrat.cloud.models = []
npars = 0
for name in pyrat.cloud.model_names:
model = pa.clouds.get_model(name)
npars += model.npars
pyrat.cloud.models.append(model)
# Parse the cloud parameters:
if pyrat.cloud.pars is not None:
if npars != len(pyrat.cloud.pars):
log.error(
'Number of input cloud parameters ({:d}) does not '
'match the number of required model parameters ({:d}).'.
format(len(pyrat.cloud.pars), npars))
j = 0
for model in pyrat.cloud.models:
npars = model.npars
model.pars = pyrat.cloud.pars[j:j + npars]
j += npars
# Check Rayleigh models:
if pyrat.rayleigh.model_names is not None:
pyrat.rayleigh.models = []
npars = 0
for name in pyrat.rayleigh.model_names:
model = pa.rayleigh.get_model(name)
npars += model.npars
pyrat.rayleigh.models.append(model)
# Process the Rayleigh parameters:
if npars == 0 and pyrat.rayleigh.pars is None:
pyrat.rayleigh.pars = []
if pyrat.rayleigh.pars is not None:
if npars != len(pyrat.rayleigh.pars):
log.error(
'Number of input Rayleigh parameters ({:d}) does not '
'match the number of required model parameters ({:d}).'.
format(len(pyrat.rayleigh.pars), npars))
j = 0
for model in pyrat.rayleigh.models:
npars = model.npars
model.pars = pyrat.rayleigh.pars[j:j + npars]
j += npars
# Check alkali arguments:
if pyrat.alkali.model_names is not None:
pyrat.alkali.models = [
pa.alkali.get_model(name, pyrat.alkali.cutoff)
for name in pyrat.alkali.model_names
]
# Accept ray-path argument:
print(pyrat.od)
if pyrat.runmode in ['spectrum', 'mcmc'] and pyrat.od.rt_path is None:
log.error("Undefined radiative-transfer observing geometry (rt_path)."
f" Select from {pc.rt_paths}.")
if 'temp' in pyrat.ret.retflag and atm.tmodelname is None:
log.error('Requested temp in retflag, but there is no tmodel.')
if 'mol' in pyrat.ret.retflag:
if atm.molmodel is None:
log.error("Requested mol in retflag, but there is no 'molmodel'.")
if atm.bulk is None:
log.error(
'Requested mol in retflag, but there are no bulk species.')
if 'ray' in pyrat.ret.retflag and pyrat.rayleigh.models == []:
log.error(
'Requested ray in retflag, but there are no rayleigh models.')
if 'cloud' in pyrat.ret.retflag and pyrat.cloud.models == []:
log.error('Requested cloud in retflag, but there are no cloud models.')
# Check system arguments:
if pyrat.od.rt_path in pc.transmission_rt and phy.rstar is None:
log.error(
'Undefined stellar radius (rstar), required for transmission '
'calculation.')
# Check raygrid:
if spec.raygrid[0] != 0:
log.error('First angle in raygrid must be 0.0 (normal to surface).')
if np.any(spec.raygrid < 0) or np.any(spec.raygrid > 90):
log.error('raygrid angles must lie between 0 and 90 deg.')
if np.any(np.ediff1d(spec.raygrid) <= 0):
log.error('raygrid angles must be monotonically increasing.')
# Store raygrid values in radians:
spec.raygrid *= sc.degree
# Gauss quadrature integration variables:
if spec.quadrature is not None:
qnodes, qweights = ss.p_roots(spec.quadrature)
spec.qnodes = 0.5 * (qnodes + 1.0)
spec.qweights = 0.5 * qweights
# Number of datapoints and filters:
if obs.data is not None:
obs.ndata = len(obs.data)
if obs.filters is not None:
obs.nfilters = len(obs.filters)
# Number checks:
if pyrat.obs.uncert is not None and pyrat.obs.ndata != len(
pyrat.obs.uncert):
log.error('Number of data uncertainty values ({:d}) does not match '
'the number of data points ({:d}).'.format(
len(pyrat.obs.uncert), pyrat.obs.ndata))
if (obs.filters is not None and obs.ndata > 0
and obs.ndata != obs.nfilters):
log.error('Number of filter bands ({:d}) does not match the '
'number of data points ({:d}).'.format(
obs.nfilters, obs.ndata))
if pyrat.ncpu >= mp.cpu_count():
log.warning('Number of requested CPUs ({:d}) is >= than the number '
'of available CPUs ({:d}). Enforced ncpu to {:d}.'.format(
pyrat.ncpu, mp.cpu_count(),
mp.cpu_count() - 1))
pyrat.ncpu = mp.cpu_count() - 1
log.head('Check spectrum done.')
MeV_to_ergs = 1.602177e-6 # factor to convert units of energy from MeV to ergs
T = 20*MeV_to_ergs/kB # temperature (kT = 20MeV)
integrand = lambda x: x**2/(exp(x)+1)
# (a) Use Gauss-Laguerre Quadrature to determine the total
# number density of electrons
[laguerre_roots,laguerre_weights] = special.l_roots(20)
weight = lambda x: exp(-x)
integral = sum(laguerre_weights*integrand(laguerre_roots)/weight(laguerre_roots))
n_electrons = 8*pi*(kB*T)**3/(2*pi*hbar*c)**3 * integral
print 'The number density of electrons is %.4e/cm^3' % n_electrons
# (b) Use Gauss-Legendre Quadrature to determine the spectral
# distribution of the electrons
[legendre_roots,legendre_weights] = special.p_roots(20)
dE = 5; Emax = 200
E_bins = linspace(0,Emax,Emax/dE+1) # MeV
x_bins = E_bins*MeV_to_ergs/(kB*T)
n_bins = zeros(len(E_bins)-1) # number density of electrons in each energy bin
for i in range(len(E_bins)-1):
a = x_bins[i]; b = x_bins[i+1]
transformed_integrand = lambda x: (b-a)/2*integrand((b-a)/2*x+(a+b)/2)
integral = sum(legendre_weights*transformed_integrand(legendre_roots))
n_bins[i] = 8*pi*(kB*T)**3/(2*pi*hbar*c)**3 * integral / (dE*MeV_to_ergs)
print 'The integral of the spectral distribution is %.4e/cm^3' % sum(n_bins*dE*MeV_to_ergs)
figure()
plot((E_bins[1:]+E_bins[:-1])/2,n_bins,'k-')
weights[i] * np.sqrt(1 - (points[i])**2) * f((b - a) * points[i] / 2 +
(b + a) / 2)
for i in range(len(points))
]) / 2
def Cheby2(m, a, b):
points = u_roots(m)[0]
weights = u_roots(m)[1]
return (b - a) * sum([(weights[i] / np.sqrt(1 - (points[i])**2)) *
f((b - a) * points[i] / 2 + (b + a) / 2)
for i in range(len(points))]) / 2
a = [5, 10]
for m in a:
# approximation results
print(GL(m))
print(Cheby1(m))
print(Cheby2(m))
# nodes
print(p_roots(m)[0])
print(t_roots(m)[0])
print(u_roots(m)[0])
# weights
print(p_roots(m)[1])
print(t_roots(m)[1])
print(u_roots(m)[1])
def check_legendre_roots(n):
xs, ws = ([], []) if n == 0 else p_roots(n) # from SciPy
xl, wl = libsharp.legendre_roots(n)
assert_allclose(xs, xl, rtol=1e-14, atol=1e-14)
assert_allclose(ws, wl, rtol=1e-14, atol=1e-14)
