def gycall(self, dae):
self.pll_gycall(dae)
self.outer_gycall(dae)
self.current_gycall(dae)
dae.add_jac(Gy, cos(dae.y[self.a] - dae.y[self.adq]), self.vd, self.v)
dae.add_jac(Gy, - mul(dae.y[self.v], sin(dae.y[self.a] - dae.y[self.adq])), self.vd, self.a)
dae.add_jac(Gy, mul(dae.y[self.v], sin(dae.y[self.a] - dae.y[self.adq])), self.vd, self.adq)
dae.add_jac(Gy, - sin(dae.y[self.a] - dae.y[self.adq]), self.vq, self.v)
dae.add_jac(Gy, - mul(dae.y[self.v], cos(dae.y[self.a] - dae.y[self.adq])), self.vq, self.a)
dae.add_jac(Gy, mul(dae.y[self.v], cos(dae.y[self.a] - dae.y[self.adq])), self.vq, self.adq)
dae.add_jac(Gy, dae.x[self.Iq], self.p, self.vq)
dae.add_jac(Gy, dae.x[self.Id], self.p, self.vd)
dae.add_jac(Gy, - dae.x[self.Id], self.q, self.vq)
dae.add_jac(Gy, dae.x[self.Iq], self.q, self.vd)
def makefig1():
pylab.figure(1, facecolor='w', figsize=(6, 6))
pylab.plot(V[0, :].T, V[1, :].T, 'b-')
nopts = 1000
angles = matrix([a * 2.0 * pi / nopts for a in range(nopts)],
(1, nopts))
circle = matrix(0.0, (2, nopts))
circle[0, :], circle[1, :] = cos(angles), sin(angles)
for k in range(len(C)):
c = C[k]
pylab.plot([c[0]], [c[1]], 'ow')
pylab.text(c[0], c[1], "s%d" % k)
pylab.plot(c[0] + circle[0, :].T, c[1] + circle[1, :].T, 'g:')
if k >= 1:
v = V[:, k - 1]
if k == 1:
dir = 0.5 * (C[k] + C[-1]) - v
else:
dir = 0.5 * (C[k] + C[k - 1]) - v
pylab.plot([v[0], v[0] + 5 * dir[0]],
[v[1], v[1] + 5 * dir[1]], 'b-')
ellipse = +circle
blas.trsm(L, ellipse, transA='T')
pylab.plot(xc[0] + ellipse[0, :].T, xc[1] + ellipse[1, :].T, 'r-')
for Xk in X:
pylab.plot([Xk[0]], [Xk[1]], 'ro')
pylab.axis([-5, 5, -5, 5])
pylab.title('Geometrical interpretation of Chebyshev bound (fig. 7.7)')
pylab.axis('off')
def gcall(self, dae):
nzeros = [0] * self.n
v = mul(self.u, dae.y[self.v])
vd = dae.y[self.vd]
vq = dae.y[self.vq]
Id = dae.y[self.Id]
Iq = dae.y[self.Iq]
self.ss = sin(dae.x[self.delta] - dae.y[self.a])
self.cc = cos(dae.x[self.delta] - dae.y[self.a])
dae.g -= spmatrix(dae.y[self.p], self.a, nzeros, (dae.m, 1), 'd')
dae.g -= spmatrix(dae.y[self.q], self.v, nzeros, (dae.m, 1), 'd')
dae.g -= spmatrix(vd - mul(v, self.ss), self.vd, nzeros, (dae.m, 1),
'd') # note d(vd)/d(delta)
dae.g -= spmatrix(vq - mul(v, self.cc), self.vq, nzeros, (dae.m, 1),
'd') # note d(vq)/d(delta)
dae.g += spmatrix(
mul(vd, Id) + mul(vq, Iq) - dae.y[self.p], self.p, nzeros,
(dae.m, 1), 'd')
dae.g += spmatrix(
mul(vq, Id) - mul(vd, Iq) - dae.y[self.q], self.q, nzeros,
(dae.m, 1), 'd')
dae.g += spmatrix(dae.y[self.pm] - self.pm0, self.pm, nzeros,
(dae.m, 1), 'd')
dae.g += spmatrix(dae.y[self.vf] - self.vf0, self.vf, nzeros,
(dae.m, 1), 'd')
def makefig1():
pylab.figure(1, facecolor='w', figsize=(6,6))
pylab.plot(V[0,:].T, V[1,:].T, 'b-')
nopts = 1000
angles = matrix( [a*2.0*pi/nopts for a in range(nopts) ],
(1,nopts) )
circle = matrix(0.0, (2,nopts))
circle[0,:], circle[1,:] = cos(angles), sin(angles)
for k in range(len(C)):
c = C[k]
pylab.plot([c[0]], [c[1]], 'og')
pylab.text(c[0], c[1], "s%d" %k)
pylab.plot(c[0] + circle[0,:].T, c[1]+circle[1,:].T, 'g:')
if k >= 1:
v = V[:,k-1]
if k==1:
dir = 0.5 * (C[k] + C[-1]) - v
else:
dir = 0.5 * (C[k] + C[k-1]) - v
pylab.plot([v[0], v[0] + 5*dir[0]],
[v[1], v[1] + 5*dir[1]], 'b-')
ellipse = +circle
blas.trsm(L, ellipse, transA='T')
pylab.plot(xc[0] + ellipse[0,:].T, xc[1]+ellipse[1,:].T, 'r-')
for Xk in X:
pylab.plot([Xk[0]], [Xk[1]], 'ro')
pylab.axis([-5, 5, -5, 5])
pylab.title('Geometrical interpretation of Chebyshev bound (fig. 7.7)')
pylab.axis('off')
def gycall(self, dae):
self.speed_gycall(dae)
self.voltage_gycall(dae)
self.current_gycall(dae)
dae.add_jac(Gy, dae.x[self.Iq], self.p, self.vq)
dae.add_jac(Gy, dae.x[self.Id], self.p, self.vd)
dae.add_jac(Gy, - dae.x[self.Id], self.q, self.vq)
dae.add_jac(Gy, dae.x[self.Iq], self.q, self.vd)
dae.add_jac(Gy, - mul(self.u, dae.y[self.v], sin(dae.y[self.a] - dae.x[self.adq])), self.vd, self.a)
dae.add_jac(Gy, mul(self.u, cos(dae.y[self.a] - dae.x[self.adq])), self.vd, self.v)
dae.add_jac(Gy, - mul(self.u, sin(dae.y[self.a] - dae.x[self.adq])), self.vq, self.v)
dae.add_jac(Gy, - mul(self.u, dae.y[self.v], cos(dae.y[self.a] - dae.x[self.adq])), self.vq, self.a)
dae.add_jac(Gy, mul(self.u, (dae.y[self.v1] - dae.y[self.v2])**-2, mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v1, self.v2)
dae.add_jac(Gy, - mul(self.u, (dae.y[self.v1] - dae.y[self.v2])**-2, mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v1, self.v1)
dae.add_jac(Gy, - mul(self.u, (dae.y[self.v1] - dae.y[self.v2])**-2, mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v2, self.v2)
dae.add_jac(Gy, mul(self.u, (dae.y[self.v1] - dae.y[self.v2])**-2, mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v2, self.v1)
def gycall(self, dae):
dae.add_jac(Gy, mul(self.xmu, 1 - dae.x[self.omega_m]), self.vrd,
self.isq)
dae.add_jac(Gy, -mul(self.xmu, 1 - dae.x[self.omega_m]), self.vrq,
self.isd)
dae.add_jac(Gy, -sin(dae.y[self.a]), self.vsd, self.v)
dae.add_jac(Gy, -mul(dae.y[self.v], cos(dae.y[self.a])), self.vsd,
self.a)
dae.add_jac(Gy, cos(dae.y[self.a]), self.vsq, self.v)
dae.add_jac(Gy, -mul(dae.y[self.v], sin(dae.y[self.a])), self.vsq,
self.a)
dae.add_jac(
Gy,
mul(0.5, self.ngen, pi, self.rho, (self.R)**2, (self.Vwn)**3,
div(1, self.mva_mega), (dae.x[self.vw])**3), self.pw, self.cp)
dae.add_jac(
Gy,
mul(-25.52, (dae.y[self.ilamb])**-2,
exp(mul(-12.5, div(1, dae.y[self.ilamb])))) + mul(
12.5, (dae.y[self.ilamb])**-2,
-1.1 + mul(25.52, div(1, dae.y[self.ilamb])) +
mul(-0.088, dae.x[self.theta_p]),
exp(mul(-12.5, div(1, dae.y[self.ilamb])))), self.cp,
self.ilamb)
dae.add_jac(
Gy,
mul((dae.y[self.lamb] + mul(0.08, dae.x[self.theta_p]))**-2,
(div(1, dae.y[self.lamb] + mul(0.08, dae.x[self.theta_p])) +
mul(-0.035, div(1, 1 + (dae.x[self.theta_p])**3)))**-2),
self.ilamb, self.lamb)
dae.add_jac(Gy, -mul(dae.y[self.isd], self.u0), self.a, self.vsd)
dae.add_jac(Gy, -mul(dae.x[self.irq], self.u0), self.a, self.vrq)
dae.add_jac(Gy, -mul(self.u0, dae.y[self.vsq]), self.a, self.isq)
dae.add_jac(Gy, -mul(dae.x[self.ird], self.u0), self.a, self.vrd)
dae.add_jac(Gy, -mul(dae.y[self.isq], self.u0), self.a, self.vsq)
dae.add_jac(Gy, -mul(self.u0, dae.y[self.vsd]), self.a, self.isd)
dae.add_jac(
Gy,
mul(
self.u0,
mul(2, dae.y[self.v], div(1, self.x0)) +
mul(dae.x[self.ird], self.xmu, div(1, self.x0))), self.v,
self.v)
def gcall(self, dae):
toSb = div(self.Sn, self.system.Settings.mva)
dae.g[self.isd] = -dae.y[self.vsd] + mul(
dae.x[self.irq], self.xmu) + mul(dae.y[self.isq], self.x0) - mul(
dae.y[self.isd], self.rs)
dae.g[self.isq] = -dae.y[self.vsq] - mul(
dae.x[self.ird], self.xmu) - mul(dae.y[self.isd], self.x0) - mul(
dae.y[self.isq], self.rs)
dae.g[self.vrd] = -dae.y[self.vrd] + mul(
1 - dae.x[self.omega_m],
mul(dae.x[self.irq], self.x1) +
mul(dae.y[self.isq], self.xmu)) - mul(dae.x[self.ird], self.rr)
dae.g[self.vrq] = -dae.y[self.vrq] - mul(
dae.x[self.irq], self.rr) - mul(
1 - dae.x[self.omega_m],
mul(dae.x[self.ird], self.x1) + mul(dae.y[self.isd], self.xmu))
dae.g[self.vsd] = -dae.y[self.vsd] - mul(dae.y[self.v],
sin(dae.y[self.a]))
dae.g[self.vsq] = -dae.y[self.vsq] + mul(dae.y[self.v],
cos(dae.y[self.a]))
dae.g[self.vref] = self.vref0 - dae.y[self.vref]
# dae.g[self.pwa] = mul(2*dae.x[self.omega_m] - 1, toSb) - dae.y[self.pwa]
dae.g[self.pwa] = mmax(mmin(2 * dae.x[self.omega_m] - 1, 1),
0) - dae.y[self.pwa]
dae.hard_limit(self.pwa, 0, 1)
dae.g[self.pw] = -dae.y[self.pw] + mul(
0.5, dae.y[self.cp], self.ngen, pi, self.rho, (self.R)**2,
(self.Vwn)**3, div(1, self.mva_mega), (dae.x[self.vw])**3)
dae.g[self.cp] = -dae.y[self.cp] + mul(
-1.1 + mul(25.52, div(1, dae.y[self.ilamb])) +
mul(-0.08800000000000001, dae.x[self.theta_p]),
exp(mul(-12.5, div(1, dae.y[self.ilamb]))))
dae.g[self.lamb] = -dae.y[self.lamb] + mul(
4, self.R, self.fn, self.ngb, dae.x[self.omega_m], pi,
div(1, self.Vwn), div(1, self.npole), div(1, dae.x[self.vw]))
dae.g[self.ilamb] = div(
1,
div(1, dae.y[self.lamb] + mul(0.08, dae.x[self.theta_p])) +
mul(-0.035, div(1, 1 +
(dae.x[self.theta_p])**3))) - dae.y[self.ilamb]
dae.g += spmatrix(
mul(
self.u0, -mul(dae.x[self.ird], dae.y[self.vrd]) -
mul(dae.x[self.irq], dae.y[self.vrq]) -
mul(dae.y[self.isd], dae.y[self.vsd]) -
mul(dae.y[self.isq], dae.y[self.vsq])), self.a, [0] * self.n,
(dae.m, 1), 'd')
dae.g += spmatrix(
mul(
self.u0,
mul((dae.y[self.v])**2, div(1, self.x0)) +
mul(dae.x[self.ird], dae.y[self.v], self.xmu, div(
1, self.x0))), self.v, [0] * self.n, (dae.m, 1), 'd')
def gcall(self, dae):
self.speed_gcall(dae)
self.voltage_gcall(dae)
self.current_gcall(dae)
dae.g[self.p] = -dae.y[self.p] + mul(dae.x[self.Id], dae.y[self.vd]) + mul(dae.x[self.Iq], dae.y[self.vq])
dae.g[self.q] = -dae.y[self.q] + mul(dae.x[self.Iq], dae.y[self.vd]) - mul(dae.x[self.Id], dae.y[self.vq])
dae.g[self.vd] = -dae.y[self.vd] + mul(self.u, dae.y[self.v], cos(dae.y[self.a] - dae.x[self.adq]))
dae.g[self.vq] = -dae.y[self.vq] - mul(self.u, dae.y[self.v], sin(dae.y[self.a] - dae.x[self.adq]))
dae.g += spmatrix(- mul(dae.y[self.p], self.u), self.a, [0]*self.n, (dae.m, 1), 'd')
dae.g += spmatrix(- mul(dae.y[self.q], self.u), self.v, [0]*self.n, (dae.m, 1), 'd')
dae.g += spmatrix(mul(self.u, div(1, dae.y[self.v1] - dae.y[self.v2]), mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v1, [0]*self.n, (dae.m, 1), 'd')
dae.g += spmatrix(- mul(self.u, div(1, dae.y[self.v1] - dae.y[self.v2]), mul(dae.x[self.Id], dae.x[self.ud]) + mul(dae.x[self.Iq], dae.x[self.uq])), self.v2, [0]*self.n, (dae.m, 1), 'd')
def cvx():
# Figures 6.8-10, pages 313-314
# Quadratic smoothing.
from math import pi
from cvxopt import blas, lapack, matrix, sin, mul, normal
n = 4000
t = matrix(list(range(n)), tc='d')
ex = 0.5 * mul(sin(2 * pi / n * t), sin(0.01 * t))
corr = ex + 0.05 * normal(n, 1)
# A = D'*D is an n by n tridiagonal matrix with -1.0 on the
# upper/lower diagonal and 1, 2, 2, ..., 2, 2, 1 on the diagonal.
Ad = matrix([1.0] + (n - 2) * [2.0] + [1.0])
As = matrix(-1.0, (n - 1, 1))
nopts = 50
deltas = -10.0 + 20.0 / (nopts - 1) * matrix(list(range(nopts)))
cost1, cost2 = [], []
for delta in deltas:
xr = +corr
lapack.ptsv(1.0 + 10 ** delta * Ad, 10 ** delta * As, xr)
cost1 += [blas.nrm2(xr - corr)]
cost2 += [blas.nrm2(xr[1:] - xr[:-1])]
# Find solutions with ||xhat - xcorr || roughly equal to 8.0, 3.1, 1.0.
time.sleep(1)
mv1, k1 = min(zip([abs(c - 8.0) for c in cost1], range(nopts)))
xr1 = +corr
lapack.ptsv(1.0 + 10 ** deltas[k1] * Ad, 10 ** deltas[k1] * As, xr1)
mv2, k2 = min(zip([abs(c - 3.1) for c in cost1], range(nopts)))
xr2 = +corr
lapack.ptsv(1.0 + 10 ** deltas[k2] * Ad, 10 ** deltas[k2] * As, xr2)
mv3, k3 = min(zip([abs(c - 1.0) for c in cost1], range(nopts)))
xr3 = +corr
lapack.ptsv(1.0 + 10 ** deltas[k3] * Ad, 10 ** deltas[k3] * As, xr3)
def init1(self, dae):
self.servcall(dae)
self.pll_init1(dae)
dae.y[self.ref1] = self.ref10
dae.y[self.ref2] = self.ref20
dae.y[self.vd] = mul(dae.y[self.v], cos(dae.y[self.a] - dae.y[self.adq]))
dae.y[self.vq] = - mul(dae.y[self.v], sin(dae.y[self.a] - dae.y[self.adq]))
self.current_init1(dae)
self.outer_init1(dae)
dae.y[self.p] = mul(dae.x[self.Id], dae.y[self.vd]) + mul(dae.x[self.Iq], dae.y[self.vq])
dae.y[self.q] = mul(dae.x[self.Iq], dae.y[self.vd]) - mul(dae.x[self.Id], dae.y[self.vq])
for idx in self.vsc:
self.system.VSC.disable(idx)
def gcall(self, dae):
self.pll_gcall(dae)
self.outer_gcall(dae)
self.current_gcall(dae)
dae.g[self.ref1] = self.ref10 - dae.y[self.ref1] \
+ mul(self.PQ + self.PV, mul(self.v12 - self.v120, self.Kdc)) \
- mul(self.PQ + self.PV, mul(dae.x[self.w] - 1), self.Kf) \
+ mul(self.vV + self.vQ, self.Kp, dae.y[self.p] - self.pref0)\
- mul(self.vV + self.vQ, mul(dae.x[self.w] - 1), self.Kf)
dae.g[self.ref2] = self.ref20 - dae.y[self.ref2]
dae.g[self.vd] = -dae.y[self.vd] + mul(dae.y[self.v], cos(dae.y[self.a] - dae.y[self.adq]))
dae.g[self.vq] = -dae.y[self.vq] - mul(dae.y[self.v], sin(dae.y[self.a] - dae.y[self.adq]))
dae.g[self.p] = -dae.y[self.p] + mul(dae.x[self.Id], dae.y[self.vd]) + mul(dae.x[self.Iq], dae.y[self.vq])
dae.g[self.q] = -dae.y[self.q] + mul(dae.x[self.Iq], dae.y[self.vd]) - mul(dae.x[self.Id], dae.y[self.vq])
dae.g += spmatrix(- dae.y[self.p], self.a, [0]*self.n, (dae.m, 1), 'd')
dae.g += spmatrix(- dae.y[self.q], self.v, [0]*self.n, (dae.m, 1), 'd')
def fxcall(self, dae):
self.speed_fxcall(dae)
self.voltage_fxcall(dae)
self.current_fxcall(dae)
dae.add_jac(Gx, dae.y[self.vq], self.p, self.Iq)
dae.add_jac(Gx, dae.y[self.vd], self.p, self.Id)
dae.add_jac(Gx, dae.y[self.vd], self.q, self.Iq)
dae.add_jac(Gx, - dae.y[self.vq], self.q, self.Id)
dae.add_jac(Gx, mul(self.u, dae.y[self.v], sin(dae.y[self.a] - dae.x[self.adq])), self.vd, self.adq)
dae.add_jac(Gx, mul(self.u, dae.y[self.v], cos(dae.y[self.a] - dae.x[self.adq])), self.vq, self.adq)
dae.add_jac(Gx, mul(self.u, dae.x[self.uq], div(1, dae.y[self.v1] - dae.y[self.v2])), self.v1, self.Iq)
dae.add_jac(Gx, mul(self.u, dae.x[self.ud], div(1, dae.y[self.v1] - dae.y[self.v2])), self.v1, self.Id)
dae.add_jac(Gx, mul(dae.x[self.Id], self.u, div(1, dae.y[self.v1] - dae.y[self.v2])), self.v1, self.ud)
dae.add_jac(Gx, mul(dae.x[self.Iq], self.u, div(1, dae.y[self.v1] - dae.y[self.v2])), self.v1, self.uq)
dae.add_jac(Gx, - mul(self.u, dae.x[self.uq], div(1, dae.y[self.v1] - dae.y[self.v2])), self.v2, self.Iq)
dae.add_jac(Gx, - mul(self.u, dae.x[self.ud], div(1, dae.y[self.v1] - dae.y[self.v2])), self.v2, self.Id)
dae.add_jac(Gx, - mul(dae.x[self.Id], self.u, div(1, dae.y[self.v1] - dae.y[self.v2])), self.v2, self.ud)
dae.add_jac(Gx, - mul(dae.x[self.Iq], self.u, div(1, dae.y[self.v1] - dae.y[self.v2])), self.v2, self.uq)
from math import pi
from cvxopt import blas, lapack, solvers
from cvxopt import matrix, spmatrix, sin, mul, div, normal
#solvers.options['show_progress'] = 0
try:
import pylab
except ImportError:
pylab_installed = False
else:
pylab_installed = True
n = 2000
t = matrix(list(range(n)), tc='d')
ex = matrix( n//4*[1.0] + n//4*[-1.0] + n//4*[1.0] + n//4*[-1.0] ) + \
0.5 * sin( 2.0*pi/n * t )
corr = ex + 0.1 * normal(n, 1)
if pylab_installed:
pylab.figure(1, facecolor='w', figsize=(8, 5))
pylab.subplot(211)
pylab.plot(t, ex)
pylab.ylabel('x[i]')
pylab.xlabel('i')
pylab.axis([0, 2000, -2, 2])
pylab.title('Original and corrupted signal (fig. 6.11)')
pylab.subplot(212)
pylab.plot(t, corr)
pylab.ylabel('xcor[i]')
pylab.xlabel('i')
pylab.axis([0, 2000, -2, 2])
# Build dictionary matrix
ts = (1.0/N) * matrix(range(N), tc='d')
B = ts[:, K*[0]] - tau * matrix(range(K), (1,K), 'd')[N*[0],:]
B = exp(-(B/sigma)**2)
A = matrix(0.0, (N, K*(2*L+1)))
# First K columns are DC pulses for k = 0,...,K-1
A[:,:K] = B
for l in range(L):
# Cosine pulses for omega = (l+1)*omega0 and k = 0,...,K-1.
A[:, K+l*(2*K) : K+l*(2*K)+K] = mul(B, cos((l+1)*omega0*ts)[:, K*[0]])
# Sine pulses for omega = (l+1)*omega0 and k = 0,...,K-1.
A[:, K+l*(2*K)+K : K+(l+1)*(2*K)] = \
mul(B, sin((l+1)*omega0*ts)[:,K*[0]])
if pylab_installed:
pylab.figure(1, facecolor='w')
pylab.subplot(311)
# DC pulse for k = 250 (tau = 0.5)
pylab.plot(ts, A[:,250])
pylab.ylabel('f(0.5, 0, c)')
pylab.axis([0, 1, -1, 1])
pylab.title('Three basis elements (fig. 6.21)')
# Cosine pulse for k = 250 (tau = 0.5) and l = 15 (omega = 75)
pylab.subplot(312)
pylab.ylabel('f(0.5, 75, c)')
pylab.plot(ts, A[:, K + 14*(2*K) + 250])
pylab.axis([0, 1, -1, 1])
B = ts[:, K * [0]] - tau * matrix(range(K), (1, K), 'd')[N * [0], :]
B = exp(-(B / sigma)**2)
A = matrix(0.0, (N, K * (2 * L + 1)))
# First K columns are DC pulses for k = 0,...,K-1
A[:, :K] = B
for l in range(L):
# Cosine pulses for omega = (l+1)*omega0 and k = 0,...,K-1.
A[:, K + l * (2 * K):K + l * (2 * K) + K] = mul(
B,
cos((l + 1) * omega0 * ts)[:, K * [0]])
# Sine pulses for omega = (l+1)*omega0 and k = 0,...,K-1.
A[:, K+l*(2*K)+K : K+(l+1)*(2*K)] = \
mul(B, sin((l+1)*omega0*ts)[:,K*[0]])
if pylab_installed:
pylab.figure(1, facecolor='w')
pylab.subplot(311)
# DC pulse for k = 250 (tau = 0.5)
pylab.plot(ts, A[:, 250])
pylab.ylabel('f(0.5, 0, c)')
pylab.axis([0, 1, -1, 1])
pylab.title('Three basis elements (fig. 6.21)')
# Cosine pulse for k = 250 (tau = 0.5) and l = 15 (omega = 75)
pylab.subplot(312)
pylab.ylabel('f(0.5, 75, c)')
pylab.plot(ts, A[:, K + 14 * (2 * K) + 250])
pylab.axis([0, 1, -1, 1])
# Figures 6.11-14, pages 315-317.
# Total variation reconstruction.
from math import pi
from cvxopt import blas, lapack, solvers
from cvxopt import matrix, spmatrix, sin, mul, div, normal
#solvers.options['show_progress'] = 0
try: import pylab
except ImportError: pylab_installed = False
else: pylab_installed = True
n = 2000
t = matrix( list(range(n)), tc='d' )
ex = matrix( n//4*[1.0] + n//4*[-1.0] + n//4*[1.0] + n//4*[-1.0] ) + \
0.5 * sin( 2.0*pi/n * t )
corr = ex + 0.1 * normal(n,1)
if pylab_installed:
pylab.figure(1, facecolor='w', figsize=(8,5))
pylab.subplot(211)
pylab.plot(t, ex)
pylab.ylabel('x[i]')
pylab.xlabel('i')
pylab.axis([0, 2000, -2, 2])
pylab.title('Original and corrupted signal (fig. 6.11)')
pylab.subplot(212)
pylab.plot(t, corr)
pylab.ylabel('xcor[i]')
pylab.xlabel('i')
pylab.axis([0, 2000, -2, 2])
def init1(self, dae):
"""New initialization function"""
self.servcall(dae)
retval = True
mva = self.system.mva
self.p0 = mul(self.p0, self.gammap)
self.q0 = mul(self.q0, self.gammaq)
dae.y[self.vsd] = mul(dae.y[self.v], -sin(dae.y[self.a]))
dae.y[self.vsq] = mul(dae.y[self.v], cos(dae.y[self.a]))
rs = matrix(self.rs)
rr = matrix(self.rr)
xmu = matrix(self.xmu)
x1 = matrix(self.xs) + xmu
x2 = matrix(self.xr) + xmu
Pg = matrix(self.p0)
Qg = matrix(self.q0)
Vc = dae.y[self.v]
vsq = dae.y[self.vsq]
vsd = dae.y[self.vsd]
toSn = div(mva, self.Sn) # to machine base
toSb = self.Sn / mva # to system base
# rotor speed
omega = 1 * (ageb(mva * Pg, self.Sn)) + \
mul(0.5 + 0.5 * mul(Pg, toSn),
aandb(agtb(Pg, 0), altb(mva * Pg, self.Sn))) + \
0.5 * (aleb(mva * Pg, 0))
slip = 1 - omega
theta = mul(self.Kp, mround(1000 * (omega - 1)) / 1000)
theta = mmax(theta, 0)
# prepare for the iterations
irq = mul(-x1, toSb, (2 * omega - 1), div(1, Vc), div(1, xmu),
div(1, omega))
isd = zeros(*irq.size)
isq = zeros(*irq.size)
# obtain ird isd isq
for i in range(self.n):
A = sparse([[-rs[i], vsq[i]], [x1[i], -vsd[i]]])
B = matrix([vsd[i] - xmu[i] * irq[i], Qg[i]])
linsolve(A, B)
isd[i] = B[0]
isq[i] = B[1]
ird = -div(vsq + mul(rs, isq) + mul(x1, isd), xmu)
vrd = -mul(rr, ird) + mul(
slip,
mul(x2, irq) + mul(xmu, isq)) # todo: check x1 or x2
vrq = -mul(rr, irq) - mul(slip, mul(x2, ird) + mul(xmu, isd))
# main iterations
for i in range(self.n):
mis = ones(6, 1)
rows = [0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5]
cols = [0, 1, 3, 0, 1, 2, 2, 4, 3, 5, 0, 1, 2]
x = matrix([isd[i], isq[i], ird[i], irq[i], vrd[i], vrq[i]])
# vals = [-rs, x1, xmu, -x1, -rs, -xmu, -rr,
# -1, -rr, -1, vsd, vsq, -xmu * Vc / x1]
vals = [
-rs[i], x1[i], xmu[i], -x1[i], -rs[i], -xmu[i], -rr[i], -1,
-rr[i], -1, vsd[i], vsq[i], -xmu[i] * Vc[i] / x1[i]
]
jac0 = spmatrix(vals, rows, cols, (6, 6), 'd')
niter = 0
while max(abs(mis)) > self.system.tds.config.tol:
if niter > 20:
logger.error('Initialization of DFIG <{}> failed.'.format(
self.name[i]))
retval = False
break
mis[0] = -rs[i] * x[0] + x1[i] * x[1] + xmu[i] * x[3] - vsd[i]
mis[1] = -rs[i] * x[1] - x1[i] * x[0] - xmu[i] * x[2] - vsq[i]
mis[2] = -rr[i] * x[2] + slip[i] * (x2[i] * x[3] +
xmu[i] * x[1]) - x[4]
mis[3] = -rr[i] * x[3] - slip[i] * (x2[i] * x[2] +
xmu[i] * x[0]) - x[5]
mis[4] = vsd[i] * x[0] + vsq[i] * x[1] + x[4] * x[2] + \
x[5] * x[3] - Pg[i]
mis[5] = -xmu[i] * Vc[i] * x[2] / x1[i] - \
Vc[i] * Vc[i] / x1[i] - Qg[i]
rows = [2, 2, 3, 3, 4, 4, 4, 4]
cols = [1, 3, 0, 2, 2, 3, 4, 5]
vals = [
slip[i] * xmu[i], slip[i] * x2[i], -slip[i] * xmu[i],
-slip[i] * x2[i], x[4], x[5], x[2], x[3]
]
jac = jac0 + spmatrix(vals, rows, cols, (6, 6), 'd')
linsolve(jac, mis)
x -= mis
niter += 1
isd[i] = x[0]
isq[i] = x[1]
ird[i] = x[2]
irq[i] = x[3]
vrd[i] = x[4]
vrq[i] = x[5]
dae.x[self.ird] = mul(self.u0, ird)
dae.x[self.irq] = mul(self.u0, irq)
dae.y[self.isd] = isd
dae.y[self.isq] = isq
dae.y[self.vrd] = vrd
dae.y[self.vrq] = vrq
dae.x[self.omega_m] = mul(self.u0, omega)
dae.x[self.theta_p] = mul(self.u0, theta)
dae.y[self.pwa] = mmax(mmin(2 * dae.x[self.omega_m] - 1, 1), 0)
self.vref0 = mul(aneb(self.KV, 0),
Vc - div(ird + div(Vc, xmu), self.KV))
dae.y[self.vref] = self.vref0
k = mul(div(x1, Vc, xmu, omega), toSb)
self.irq_off = -mul(k, mmax(mmin(2 * omega - 1, 1), 0)) - irq
# electrical torque in pu
te = mul(
xmu,
mul(dae.x[self.irq], dae.y[self.isd]) -
mul(dae.x[self.ird], dae.y[self.isq]))
for i in range(self.n):
if te[i] < 0:
logger.error(
'Pe < 0 on bus <{}>. Wind speed initialize failed.'.format(
self.bus[i]))
retval = False
# wind power in pu
pw = mul(te, omega)
dae.y[self.pw] = pw
# wind speed initialization loop
R = 4 * pi * self.system.freq * mul(self.R, self.ngb, div(
1, self.npole))
AA = pi * self.R**2
vw = 0.9 * self.Vwn
for i in range(self.n):
mis = 1
niter = 0
while abs(mis) > self.system.tds.config.tol:
if niter > 50:
logger.error(
'Wind <{}> init failed. '
'Try increasing the nominal wind speed.'.format(
self.wind[i]))
retval = False
break
pw_iter, jac = self.windpower(self.ngen[i], self.rho[i], vw[i],
AA[i], R[i], omega[i], theta[i])
mis = pw_iter - pw[i]
inc = -mis / jac[1]
vw[i] += inc
niter += 1
# set wind speed
dae.x[self.vw] = div(vw, self.Vwn)
lamb = div(omega, vw, div(1, R))
ilamb = div(1,
(div(1, lamb + 0.08 * theta) - div(0.035, theta**3 + 1)))
cp = 0.22 * mul(
div(116, ilamb) - 0.4 * theta - 5, exp(div(-12.5, ilamb)))
dae.y[self.lamb] = lamb
dae.y[self.ilamb] = ilamb
dae.y[self.cp] = cp
self.system.rmgen(self.gen)
if not retval:
logger.error('DFIG initialization failed')
return retval
# Figures 6.8-10, pages 313-314
# Quadratic smoothing.
from math import pi
from cvxopt import blas, lapack, matrix, sin, mul, normal
try:
import pylab
except ImportError:
pylab_installed = False
else:
pylab_installed = True
n = 4000
t = matrix(list(range(n)), tc='d')
ex = 0.5 * mul(sin(2 * pi / n * t), sin(0.01 * t))
corr = ex + 0.05 * normal(n, 1)
if pylab_installed:
pylab.figure(1, facecolor='w', figsize=(8, 5))
pylab.subplot(211)
pylab.plot(t, ex)
pylab.ylabel('x[i]')
pylab.xlabel('i')
pylab.title('Original and corrupted signal (fig. 6.8)')
pylab.subplot(212)
pylab.plot(t, corr)
pylab.ylabel('xcor[i]')
pylab.xlabel('i')
# A = D'*D is an n by n tridiagonal matrix with -1.0 on the
# upper/lower diagonal and 1, 2, 2, ..., 2, 2, 1 on the diagonal.
# Tikhonov solution: minimize || A*x - b ||_2^2 + 0.1*||x||^2_2 xtik = A.T*b S = A.T*A S[::n+1] += 0.1 lapack.posv(S, xtik) # Worst case solution xwc = wcls(A, Ap, b) notrials = 100000 r = sqrt(uniform(1,notrials)) theta = 2.0 * pi * uniform(1,notrials) u = matrix(0.0, (2,notrials)) u[0,:] = mul(r, cos(theta)) u[1,:] = mul(r, sin(theta)) # LS solution q = A*xls - b P = matrix(0.0, (m,2)) P[:,0], P[:,1] = Ap[0]*xls, Ap[1]*xls r = P*u + q[:,notrials*[0]] resls = sqrt( matrix(1.0, (1,m)) * mul(r,r) ) q = A*xtik - b P[:,0], P[:,1] = Ap[0]*xtik, Ap[1]*xtik r = P*u + q[:,notrials*[0]] restik = sqrt( matrix(1.0, (1,m)) * mul(r,r) ) q = A*xwc - b P[:,0], P[:,1] = Ap[0]*xwc, Ap[1]*xwc
def gycall(self, dae):
if sum(self.u) == 0:
return
Zsh = self.rsh + 1j * self.xsh
iZsh = div(self.u, abs(Zsh))
Vh = polar(dae.y[self.v], dae.y[self.a] * 1j)
Vsh = polar(dae.y[self.vsh], dae.y[self.ash] * 1j)
Ish = div(Vsh - Vh + 1e-6, Zsh)
iIsh = div(self.u, Ish)
gsh = div(self.u, Zsh).real()
bsh = div(self.u, Zsh).imag()
V = dae.y[self.v]
theta = dae.y[self.a]
Vsh = dae.y[self.vsh]
thetash = dae.y[self.ash]
Vdc = dae.y[self.v1] - dae.y[self.v2]
iVdc2 = div(self.u, Vdc ** 2)
dae.add_jac(Gy, div(self.u, Vdc), self.v1, self.pdc)
dae.add_jac(Gy, -mul(self.u, dae.y[self.pdc], iVdc2), self.v1, self.v1)
dae.add_jac(Gy, mul(self.u, dae.y[self.pdc], iVdc2), self.v1, self.v2)
dae.add_jac(Gy, -div(self.u, Vdc), self.v2, self.pdc)
dae.add_jac(Gy, mul(self.u, dae.y[self.pdc], iVdc2), self.v2, self.v1)
dae.add_jac(Gy, -mul(self.u, dae.y[self.pdc], iVdc2), self.v2, self.v2)
dae.add_jac(Gy, -2*mul(gsh, V) + mul(gsh, Vsh, cos(theta - thetash)) + mul(bsh, Vsh, sin(theta - thetash)), self.ash, self.v)
dae.add_jac(Gy, mul(gsh, V, cos(theta - thetash)) + mul(bsh, V, sin(theta - thetash)), self.ash, self.vsh)
dae.add_jac(Gy, -mul(gsh, V, Vsh, sin(theta - thetash)) + mul(bsh, V, Vsh, cos(theta - thetash)), self.ash, self.a)
dae.add_jac(Gy, mul(gsh, V, Vsh, sin(theta - thetash)) - mul(bsh, V, Vsh, cos(theta - thetash)), self.ash, self.ash)
dae.add_jac(Gy, 2*mul(bsh, V) + mul(gsh, Vsh, sin(theta - thetash)) - mul(bsh, Vsh, cos(theta - thetash)), self.vsh, self.v)
dae.add_jac(Gy, mul(gsh, V, sin(theta - thetash)) - mul(bsh, V, cos(theta - thetash)), self.vsh, self.vsh)
dae.add_jac(Gy, mul(gsh, V, Vsh, cos(theta - thetash)) + mul(bsh, V, Vsh, sin(theta - thetash)), self.vsh, self.a)
dae.add_jac(Gy, -mul(gsh, V, Vsh, cos(theta - thetash)) - mul(bsh, V, Vsh, sin(theta - thetash)), self.vsh, self.ash)
dae.add_jac(Gy, 0.5 * mul(self.u, 2*V - 2*mul(Vsh, cos(theta - thetash)), abs(iIsh), abs(iZsh) ** 2), self.Ish, self.v)
dae.add_jac(Gy, 0.5 * mul(self.u, 2*Vsh - 2*mul(V, cos(theta - thetash)), abs(iIsh), abs(iZsh) ** 2), self.Ish, self.vsh)
dae.add_jac(Gy, 0.5 * mul(self.u, 2*V, Vsh, sin(theta-thetash), abs(iIsh), abs(iZsh) ** 2), self.Ish, self.a)
dae.add_jac(Gy, 0.5 * mul(self.u, 2*V, Vsh, - sin(theta - thetash), abs(iIsh), abs(iZsh) ** 2), self.Ish, self.ash)
dae.add_jac(Gy, -2 * mul(self.u, self.k2, dae.y[self.Ish]), self.pdc, self.Ish)
dae.add_jac(Gy, mul(2 * gsh, Vsh) - mul(gsh, V, cos(theta - thetash)) + mul(bsh, V, sin(theta - thetash)), self.pdc, self.vsh)
dae.add_jac(Gy, -mul(gsh, Vsh, cos(theta - thetash)) + mul(bsh, Vsh, sin(theta - thetash)), self.pdc, self.v)
dae.add_jac(Gy, mul(gsh, V, Vsh, sin(theta - thetash)) + mul(bsh, V, Vsh, cos(theta - thetash)), self.pdc, self.a)
dae.add_jac(Gy, -mul(gsh, V, Vsh, sin(theta - thetash)) - mul(bsh, V, Vsh, cos(theta - thetash)), self.pdc, self.ash)
for gidx, yidx in zip(self.glim, self.ylim):
dae.set_jac(Gy, 0.0, [gidx] * dae.m, range(dae.m))
dae.set_jac(Gy, 1.0, [gidx], [yidx])
dae.set_jac(Gy, -1e-6, [gidx], [gidx])
# Figures 6.8-10, pages 313-314
# Quadratic smoothing.
from math import pi
from cvxopt import blas, lapack, matrix, sin, mul, normal
try: import pylab
except ImportError: pylab_installed = False
else: pylab_installed = True
n = 4000
t = matrix(list(range(n)), tc='d')
ex = 0.5 * mul( sin(2*pi/n * t), sin(0.01 * t))
corr = ex + 0.05 * normal(n,1)
if pylab_installed:
pylab.figure(1, facecolor='w', figsize=(8,5))
pylab.subplot(211)
pylab.plot(t, ex)
pylab.ylabel('x[i]')
pylab.xlabel('i')
pylab.title('Original and corrupted signal (fig. 6.8)')
pylab.subplot(212)
pylab.plot(t, corr)
pylab.ylabel('xcor[i]')
pylab.xlabel('i')
# A = D'*D is an n by n tridiagonal matrix with -1.0 on the
# upper/lower diagonal and 1, 2, 2, ..., 2, 2, 1 on the diagonal.
Ad = matrix([1.0] + (n-2)*[2.0] + [1.0])
As = matrix(-1.0, (n-1,1))
if pylab_installed:
pylab.figure(1, facecolor='w')
pylab.plot(X[:, 0], X[:, 1], 'ko', X[:, 0], X[:, 1], '-k')
# Ellipsoid in the form { x | || L' * (x-c) ||_2 <= 1 }
L = +A
lapack.potrf(L)
c = +b
lapack.potrs(L, c)
# 1000 points on the unit circle
nopts = 1000
angles = matrix([a * 2.0 * pi / nopts for a in range(nopts)], (1, nopts))
circle = matrix(0.0, (2, nopts))
circle[0, :], circle[1, :] = cos(angles), sin(angles)
# ellipse = L^-T * circle + c
blas.trsm(L, circle, transA='T')
ellipse = circle + c[:, nopts * [0]]
ellipse2 = 0.5 * circle + c[:, nopts * [0]]
pylab.plot(ellipse[0, :].T, ellipse[1, :].T, 'k-')
pylab.fill(ellipse2[0, :].T, ellipse2[1, :].T, facecolor='#F0F0F0')
pylab.title('Loewner-John ellipsoid (fig 8.3)')
pylab.axis('equal')
pylab.axis('off')
# Maximum volume enclosed ellipsoid
#
# minimize -log det B
# Tikhonov solution: minimize || A*x - b ||_2^2 + 0.1*||x||^2_2 xtik = A.T * b S = A.T * A S[::n + 1] += 0.1 lapack.posv(S, xtik) # Worst case solution xwc = wcls(A, Ap, b) notrials = 100000 r = sqrt(uniform(1, notrials)) theta = 2.0 * pi * uniform(1, notrials) u = matrix(0.0, (2, notrials)) u[0, :] = mul(r, cos(theta)) u[1, :] = mul(r, sin(theta)) # LS solution q = A * xls - b P = matrix(0.0, (m, 2)) P[:, 0], P[:, 1] = Ap[0] * xls, Ap[1] * xls r = P * u + q[:, notrials * [0]] resls = sqrt(matrix(1.0, (1, m)) * mul(r, r)) q = A * xtik - b P[:, 0], P[:, 1] = Ap[0] * xtik, Ap[1] * xtik r = P * u + q[:, notrials * [0]] restik = sqrt(matrix(1.0, (1, m)) * mul(r, r)) q = A * xwc - b P[:, 0], P[:, 1] = Ap[0] * xwc, Ap[1] * xwc
def gycall(self, dae):
Zsh = self.rsh + 1j * self.xsh
iZsh = div(1, abs(Zsh))
V = polar(dae.y[self.v], dae.y[self.a] * 1j)
Vsh = polar(dae.y[self.vsh], dae.y[self.ash] * 1j)
Ish = div(V - Vsh, Zsh)
iIsh = div(1, Ish)
gsh = div(1, Zsh).real()
bsh = div(1, Zsh).imag()
V = dae.y[self.v]
theta = dae.y[self.a]
Vsh = dae.y[self.vsh]
thetash = dae.y[self.ash]
Vdc = dae.y[self.v1] - dae.y[self.v2]
dae.add_jac(Gy, -div(1, Vdc), self.v1, self.pdc)
dae.add_jac(Gy, div(dae.y[self.pdc], mul(Vdc, Vdc)), self.v1, self.v1)
dae.add_jac(Gy, -div(dae.y[self.pdc], mul(Vdc, Vdc)), self.v1, self.v2)
dae.add_jac(Gy, div(1, Vdc), self.v2, self.pdc)
dae.add_jac(Gy, -div(dae.y[self.pdc], mul(Vdc, Vdc)), self.v2, self.v1)
dae.add_jac(Gy, div(dae.y[self.pdc], mul(Vdc, Vdc)), self.v2, self.v2)
dae.add_jac(
Gy, 2 * mul(gsh, V) - mul(gsh, Vsh, cos(theta - thetash)) -
mul(bsh, Vsh, sin(theta - thetash)), self.ash, self.v)
dae.add_jac(
Gy, -mul(gsh, V, cos(theta - thetash)) -
mul(bsh, V, sin(theta - thetash)), self.ash, self.vsh)
dae.add_jac(
Gy,
mul(gsh, V, Vsh, sin(theta - thetash)) -
mul(bsh, V, Vsh, cos(theta - thetash)), self.ash, self.a)
dae.add_jac(
Gy, -mul(gsh, V, Vsh, sin(theta - thetash)) +
mul(bsh, V, Vsh, cos(theta - thetash)) + 1e-6, self.ash, self.ash)
dae.add_jac(
Gy, -2 * mul(bsh, V) - mul(gsh, Vsh, sin(theta - thetash)) +
mul(bsh, Vsh, cos(theta - thetash)), self.vsh, self.v)
dae.add_jac(
Gy, -mul(gsh, V, sin(theta - thetash)) +
mul(bsh, V, cos(theta - thetash)), self.vsh, self.vsh)
dae.add_jac(
Gy, -mul(gsh, V, Vsh, cos(theta - thetash)) -
mul(bsh, V, Vsh, sin(theta - thetash)), self.vsh, self.a)
dae.add_jac(
Gy,
mul(gsh, V, Vsh, cos(theta - thetash)) +
mul(bsh, V, Vsh, sin(theta - thetash)), self.vsh, self.ash)
dae.add_jac(
Gy,
0.5 * mul(2 * V - 2 * mul(Vsh, cos(theta - thetash)), abs(iIsh),
abs(iZsh), abs(iZsh)), self.Ish, self.v)
dae.add_jac(
Gy,
0.5 * mul(2 * Vsh - 2 * mul(V, cos(theta - thetash)), abs(iIsh),
abs(iZsh), abs(iZsh)), self.Ish, self.vsh)
dae.add_jac(
Gy,
0.5 * mul(2 * V, Vsh, sin(theta - thetash), abs(iIsh), abs(iZsh),
abs(iZsh)), self.Ish, self.a)
dae.add_jac(
Gy, 0.5 * mul(2 * V, Vsh, -sin(theta - thetash), abs(iIsh),
abs(iZsh), abs(iZsh)), self.Ish, self.ash)
dae.add_jac(Gy, -2 * mul(self.k2, dae.y[self.Ish]), self.pdc, self.Ish)
dae.add_jac(
Gy, -mul(2 * gsh, Vsh) + mul(gsh, V, cos(theta - thetash)) -
mul(bsh, V, sin(theta - thetash)), self.pdc, self.vsh)
dae.add_jac(
Gy,
mul(gsh, Vsh, cos(theta - thetash)) -
mul(bsh, Vsh, sin(theta - thetash)), self.pdc, self.v)
dae.add_jac(
Gy, -mul(gsh, V, Vsh, sin(theta - thetash)) -
mul(bsh, V, Vsh, cos(theta - thetash)), self.pdc, self.a)
dae.add_jac(
Gy,
mul(gsh, V, Vsh, sin(theta - thetash)) +
mul(bsh, V, Vsh, cos(theta - thetash)), self.pdc, self.ash)
dae.add_jac(Gy, -self.R, self.pdc, self.v1)
for gidx, yidx in zip(self.glim, self.ylim):
dae.set_jac(Gy, 0.0, [gidx] * dae.m, range(dae.m))
dae.set_jac(Gy, 1.0, [gidx], [yidx])
dae.set_jac(Gy, 1e-6, [gidx], [gidx])
if pylab_installed:
pylab.figure(1, facecolor='w')
pylab.plot(X[:,0], X[:,1], 'ko', X[:,0], X[:,1], '-k')
# Ellipsoid in the form { x | || L' * (x-c) ||_2 <= 1 }
L = +A
lapack.potrf(L)
c = +b
lapack.potrs(L, c)
# 1000 points on the unit circle
nopts = 1000
angles = matrix( [ a*2.0*pi/nopts for a in range(nopts) ], (1,nopts) )
circle = matrix(0.0, (2,nopts))
circle[0,:], circle[1,:] = cos(angles), sin(angles)
# ellipse = L^-T * circle + c
blas.trsm(L, circle, transA='T')
ellipse = circle + c[:, nopts*[0]]
ellipse2 = 0.5 * circle + c[:, nopts*[0]]
pylab.plot(ellipse[0,:].T, ellipse[1,:].T, 'k-')
pylab.fill(ellipse2[0,:].T, ellipse2[1,:].T, facecolor = '#F0F0F0')
pylab.title('Loewner-John ellipsoid (fig 8.3)')
pylab.axis('equal')
pylab.axis('off')
# Maximum volume enclosed ellipsoid
#
from math import pi
from cvxopt import blas, lapack, solvers
from cvxopt import matrix, spmatrix, sin, mul, div, normal
# solvers.options['show_progress'] = 0
try:
import pylab
except ImportError:
pylab_installed = False
else:
pylab_installed = True
n = 2000
t = matrix(list(range(n)), tc="d")
ex = matrix(n // 4 * [1.0] + n // 4 * [-1.0] + n // 4 * [1.0] + n // 4 * [-1.0]) + 0.5 * sin(2.0 * pi / n * t)
corr = ex + 0.1 * normal(n, 1)
if pylab_installed:
pylab.figure(1, facecolor="w", figsize=(8, 5))
pylab.subplot(211)
pylab.plot(t, ex)
pylab.ylabel("x[i]")
pylab.xlabel("i")
pylab.axis([0, 2000, -2, 2])
pylab.title("Original and corrupted signal (fig. 6.11)")
pylab.subplot(212)
pylab.plot(t, corr)
pylab.ylabel("xcor[i]")
pylab.xlabel("i")
pylab.axis([0, 2000, -2, 2])