for t in range(T): for i in range(N): # j = 1 # Propagate Xcur[i,:,0] = a*Xprev[i,:,0] + (1/np.sqrt(tauRho))*np.random.normal(size=M) # Weight logW = logPhi(Xcur[i,:,0],y[0,t]) maxLogW = np.max(logW) w = np.exp(logW - maxLogW) logZ[i] = maxLogW + np.log(np.sum(w))-np.log(M) w /= np.sum(w) # Resample ancestors = hlp.resampling(w) Xprev[i,:,:] = Xprev[i,ancestors,:] Xcur[i,:,0] = Xcur[i,ancestors,0] # j = 2:d for j in np.arange(1,d): # Propagate tau = tauRho + tauPsi mu = (tauRho*a*Xprev[i, :, j] + tauPsi*Xcur[i,:,j-1])/tau Xcur[i,:,j] = mu + (1/np.sqrt(tau))*np.random.normal(size=M) # Weighting logW = logPhi(Xcur[i, :, j],y[j,t]) maxLogW = np.max(logW) w = np.exp(logW - maxLogW) logZ[i] += maxLogW + np.log(np.sum(w))-np.log(M)
def runNested(d, tauPhi, N, M, nrRuns):
r"""Run NSMC filtering on high-dimensional LGSS.
Parameters
----------
d : int
State dimension.
tauPhi : float
Measurement precision.
N : int
Number of particles, 1st level.
M : int
Number of particles, 2nd level.
nrRuns : int
Number of independent runs of the algorithm.
Returns
-------
Saves E[X] and E[X**2] estimates.
"""
# Model init
a = 0.5
tauPsi = 1.
tauRho = 1.
params = hlp.params(a=a, tauPsi=tauPsi, tauRho=tauRho, tauPhi=tauPhi)
filename = 'simulatedData/d' + str(d) + 'tauPhi' + str(tauPhi) + 'y.txt'
y = np.loadtxt(filename)
T = y.shape[1]
for j in range(nrRuns):
# Algorithm init
logZ = np.zeros(N)
ancestors = np.zeros(N)
X = np.zeros((N, d))
ESS = np.zeros(T)
# Setup new file
filename = './results/paper/d' + str(d) + '_N' + str(N) + '_M' + str(
M) + 'tauPhi' + str(tauPhi) + '_nestedSMCrun' + str(j + 1) + '.csv'
f = open(filename, 'w')
#f.write('Iter ESS E[x] E[x**2]\n')
f.close()
for t in range(T):
q = [
nsmc.nestedFAPF(params, y[:, t], M, X[i, :]) for i in range(N)
]
for i in range(N):
logZ[i] = q[i].logZ
maxLz = np.max(logZ)
w = np.exp(logZ - maxLz)
w /= np.sum(w)
ESS[t] = 1 / np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(N):
X[i, :] = q[ancestors[i]].simulate(1, BS=True)
f = open(filename, 'a')
tmpVec = np.r_[t + 1, ESS[t],
np.mean(X, axis=0),
np.mean(X**2, axis=0)]
np.savetxt(f, tmpVec.reshape((1, len(tmpVec))), delimiter=',')
f.close()
def __init__(self, t, N, M, xCond=None): C1 = 0.5 C2 = 3. # Model init xDomain = np.arange(2) # Load parameters region = 'dustBowl' #region = 'sahel' filename = 'parameters/'+region+'Sigma2_N35-55_W90-120_downsampled.csv' sigma2 = np.loadtxt(filename, delimiter=',') filename = 'parameters/'+region+'MuAb_N35-55_W90-120_downsampled.csv' muAb = np.loadtxt(filename, delimiter=',') filename = 'parameters/'+region+'MuNorm_N35-55_W90-120_downsampled.csv' muNorm = np.loadtxt(filename, delimiter=',') filename = 'processedData/'+region+'Yt'+str(t)+'_N35-55_W90-120_downsampled.csv' Y = np.loadtxt(filename, delimiter=',') I = Y.shape[0] J = Y.shape[1] # SMC init X = np.zeros( (N, I, J), dtype=bool ) ancestors = np.zeros( N ) logZ = 0. logW = np.zeros( N ) w = np.zeros( N ) ESS = np.zeros( J ) # --------------- # SMC # --------------- # SMC first iteration params = hlp.params(I = I, muAb = muAb[:,0], muNorm = muNorm[:,0], sigma2 = sigma2[:,0]) if xCond is not None: q = [nested.inner(params, Y[:,0], M, xCond[:,0]) for i in range(N)] else: q = [nested.inner(params, Y[:,0], M) for i in range(N)] logW = np.array([q[i].logZ for i in range(N)]) maxLogW = np.max(logW) w = np.exp(logW - maxLogW) logZ = maxLogW + np.log(np.sum(w)) - np.log(N) w /= np.sum(w) #print w.shape ESS[0] = 1/np.sum(w**2) #print 'ESS: ',ESS[0] #print 'First logZ: ',logZ ancestors = hlp.resampling(w) for i in range(N): X[i,:,0] = q[ancestors[i]].simulate() ## SMC MAIN LOOP for j in np.arange(1,J): #print j params = hlp.params(I = I, muAb = muAb[:,j], muNorm = muNorm[:,j], sigma2 = sigma2[:,j]) if xCond is not None: q = [nested.inner(params, Y[:,j], M, xCond[:,j], X[i,:,j-1]) for i in range(N)] else: q = [nested.inner(params, Y[:,j], M, xSpaceCond = X[i,:,j-1]) for i in range(N)] logW = np.array([q[i].logZ for i in range(N)]) maxLogW = np.max(logW) w = np.exp(logW - maxLogW) logZ += maxLogW + np.log(np.sum(w)) - np.log(N) #print 'j: ',j,' logZ',logZ #print 'logW: ',logW #print 'Y: ',Y[:,j] w /= np.sum(w) #print 'Max w: ',np.max(w) ESS[j] = 1/np.sum(w**2) #print 'ESS: ',ESS[j] ancestors = hlp.resampling(w) for i in range(N): X[i,:,j] = q[ancestors[i]].simulate() #print 'Last logZ: ',logZ ## Save init to class object self.N = N self.J = J self.I = I self.X = X self.logZ = logZ self.w = w self.xCond = xCond self.ESS = ESS
def runNested(d, tauPhi, N, M, nrRuns):
r"""Run NSMC filtering on high-dimensional LGSS.
Parameters
----------
d : int
State dimension.
tauPhi : float
Measurement precision.
N : int
Number of particles, 1st level.
M : int
Number of particles, 2nd level.
nrRuns : int
Number of independent runs of the algorithm.
Returns
-------
Saves E[X] and E[X**2] estimates.
"""
# Model init
a = 0.5
tauPsi = 1.
tauRho = 1.
params = hlp.params(a = a,tauPsi = tauPsi,tauRho = tauRho,tauPhi = tauPhi)
filename = 'simulatedData/d'+str(d)+'tauPhi'+str(tauPhi)+'y.txt'
y = np.loadtxt(filename)
T = y.shape[1]
for j in range(nrRuns):
# Algorithm init
logZ = np.zeros(N)
ancestors = np.zeros(N)
X = np.zeros((N,d))
ESS = np.zeros(T)
# Setup new file
filename = './results/paper/d'+str(d)+'_N'+str(N)+'_M'+str(M)+'tauPhi'+str(tauPhi)+'_nestedSMCrun'+str(j+1)+'.csv'
f = open(filename, 'w')
#f.write('Iter ESS E[x] E[x**2]\n')
f.close()
for t in range(T):
q = [ nsmc.nestedFAPF(params, y[:,t], M, X[i,:]) for i in range(N) ]
for i in range(N):
logZ[i] = q[i].logZ
maxLz = np.max(logZ)
w = np.exp(logZ-maxLz)
w /= np.sum(w)
ESS[t] = 1/np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(N):
X[i,:] = q[ancestors[i]].simulate(1,BS=True)
f = open(filename, 'a')
tmpVec = np.r_[t+1, ESS[t], np.mean(X,axis=0), np.mean(X**2,axis=0)]
np.savetxt(f, tmpVec.reshape((1,len(tmpVec))),delimiter=',')
f.close()
def __init__(self, params, y, N, xTimeCond=None, xSpaceCond=None):
C1 = 0.5
C2 = 3.
# Model init
xDomain = np.arange(2)
def logPhi(x, y, sig2, mu_ab, mu_norm):
return -0.5 * (y - mu_ab * x.astype('float') - mu_norm *
(1. - x.astype('float')))**2 / sig2
I = params.I
muAb = params.muAb
muNorm = params.muNorm
sigma2 = params.sigma2
# SMC init
X = np.zeros((N, I), dtype=bool)
ancestors = np.zeros(N)
logZ = 0.
logW = np.zeros(N)
w = np.zeros(N)
# ---------------
# SMC
# ---------------
# Sample proposal
tempDist = np.zeros(2)
if xTimeCond is not None:
tempDist += C2 * (xTimeCond[0] == xDomain.astype(bool))
if xSpaceCond is not None:
tempDist += C1 * (xSpaceCond[0] == xDomain.astype(bool))
tempDist = np.exp(tempDist)
tempDist /= np.sum(tempDist)
X[:, 0] = hlp.discreteSampling(tempDist, xDomain, N)
# Weighting
logW = logPhi(X[:, 0], y[0], sigma2[0], muAb[0], muNorm[0])
maxLogW = np.max(logW)
w = np.exp(logW - maxLogW)
logZ = maxLogW + np.log(np.sum(w)) - np.log(N)
w /= np.sum(w)
ancestors = hlp.resampling(w)
X[:, 0] = X[ancestors, 0]
## SMC MAIN LOOP
for i in np.arange(1, I):
tempDist = np.zeros(2)
if xTimeCond is not None:
tempDist += C2 * (xTimeCond[i] == xDomain.astype(bool))
if xSpaceCond is not None:
tempDist += C1 * (xSpaceCond[i] == xDomain.astype(bool))
for iParticle in range(N):
tempParticleDist = tempDist + C1 * (X[iParticle, i - 1]
== xDomain.astype(bool))
tempParticleDist = np.exp(tempParticleDist)
tempParticleDist /= np.sum(tempParticleDist)
X[iParticle, i] = hlp.discreteSampling(tempParticleDist,
xDomain, 1)
logW = logPhi(X[:, i], y[i], sigma2[i], muAb[i], muNorm[i])
maxLogW = np.max(logW)
w = np.exp(logW - maxLogW)
logZ += maxLogW + np.log(np.sum(w)) - np.log(N)
#if math.isnan(logZ):
#print 'X: ',X[:,i]
#print 'y: ',y[i]
#print 'muAb: ',muAb[i]
#print 'muNorm: ',muNorm[i]
#print 'sig2: ',sigma2[i]
#raw_input()
w /= np.sum(w)
ancestors = hlp.resampling(w)
X[:, i] = X[ancestors, i]
## Save init to class object
self.N = N
self.C1 = C1
self.I = I
self.X = X
self.y = y
self.logZ = logZ
self.w = w
def __init__(self, params, Y, N, xCond=None): # Model init d = len(Y) def logPhi(x,y): return -0.5*params.tauPhi*(x-y)**2 # SMC init if xCond is None: xCond = np.zeros( d ) logZ = 0. X = np.zeros( (N, d) ) Xa = np.zeros( (N, d) ) ancestors = np.zeros( N ) w = np.zeros( (N, d) ) W = np.zeros( (N, d) ) logW = np.zeros( N ) #ESS = np.zeros( d ) #NT = N/2 #resamp = 0 # i=1 X[:,0] = params.tauRho*params.a*xCond[0] + (1/np.sqrt(params.tauRho))*np.random.normal(size=N) # Weighting logW = logPhi(X[:,0],Y[0]) maxLogW = np.max(logW) w[:,0] = np.exp(logW - maxLogW) logZ += maxLogW + np.log(np.sum(w[:,0])) - np.log(N) w[:,0] /= np.sum(w[:,0]) ancestors = hlp.resampling(w[:,0]) X[:,0] = X[ancestors,0] Xa[:,0] = X[:,0] #tempW = w[:,0] / np.sum(w[:,0]) #ESS[0] = 1/np.sum(tempW**2) #if ESS[0] < NT: #logZ += maxLogW + np.log(np.sum(w[:,0])) - np.log(N) #w[:,0] /= np.sum(w[:,0]) #ancestors = hlp.resampling(w[:,0],scheme='sys') #X[:,0] = X[ancestors,0] #logW = np.zeros( N ) #else: #ancestors = np.arange(N) # i=2:d for i in np.arange(1,d): # Propagate tau = params.tauRho + params.tauPsi mu = (params.tauRho*params.a*xCond[i] + params.tauPsi*X[:,i-1])/tau X[:,i] = mu + (1/np.sqrt(tau))*np.random.normal(size=N) # Weighting, Resampling logW = logPhi(X[:,i],Y[i]) maxLogW = np.max(logW) w[:,i] = np.exp(logW - maxLogW) logZ += maxLogW + np.log(np.sum(w[:,i])) - np.log(N) w[:,i] /= np.sum(w[:,i]) ancestors = hlp.resampling(w[:,i]) X[:,i] = X[ancestors,i] Xa[:,:i] = Xa[ancestors,:i] Xa[:,i] = X[:,i] #tempW = w[:,i] / np.sum(w[:,i]) #ESS[i] = 1/np.sum(tempW**2) ## ESS-based Resampling #if ESS[i] < NT or i == d-1: #logZ += maxLogW + np.log(np.sum(w[:,i])) - np.log(N) #w[:,i] /= np.sum(w[:,i]) #ancestors = hlp.resampling(w[:,i],scheme='sys') #X[:,i] = X[ancestors,i] #logW = np.zeros( N ) #else: #ancestors = np.arange(N) # Save init to class object self.N = N self.d = d self.X = X self.Xa = Xa self.Y = Y self.params = params self.logZ = logZ self.w = w self.xCond = xCond
def __init__(self, params, y, N, xTimeCond=None, xSpaceCond=None):
C1 = 0.5
C2 = 3.
# Model init
xDomain = np.arange(2)
def logPhi(x,y,sig2,mu_ab,mu_norm): return -0.5*(y-mu_ab*x.astype('float')-mu_norm*(1.-x.astype('float')))**2/sig2
I = params.I
muAb = params.muAb
muNorm = params.muNorm
sigma2 = params.sigma2
# SMC init
X = np.zeros( (N, I), dtype=bool )
ancestors = np.zeros( N )
logZ = 0.
logW = np.zeros( N )
w = np.zeros( N )
# ---------------
# SMC
# ---------------
# Sample proposal
tempDist = np.zeros(2)
if xTimeCond is not None:
tempDist += C2*(xTimeCond[0] == xDomain.astype(bool))
if xSpaceCond is not None:
tempDist += C1*(xSpaceCond[0] == xDomain.astype(bool))
tempDist = np.exp(tempDist)
tempDist /= np.sum(tempDist)
X[:,0] = hlp.discreteSampling(tempDist, xDomain, N)
# Weighting
logW = logPhi(X[:,0], y[0], sigma2[0], muAb[0], muNorm[0])
maxLogW = np.max(logW)
w = np.exp(logW-maxLogW)
logZ = maxLogW + np.log(np.sum(w)) - np.log(N)
w /= np.sum(w)
ancestors = hlp.resampling(w)
X[:,0] = X[ancestors,0]
## SMC MAIN LOOP
for i in np.arange(1,I):
tempDist = np.zeros(2)
if xTimeCond is not None:
tempDist += C2*(xTimeCond[i] == xDomain.astype(bool))
if xSpaceCond is not None:
tempDist += C1*(xSpaceCond[i] == xDomain.astype(bool))
for iParticle in range(N):
tempParticleDist = tempDist+C1*(X[iParticle,i-1] == xDomain.astype(bool))
tempParticleDist = np.exp(tempParticleDist)
tempParticleDist /= np.sum(tempParticleDist)
X[iParticle,i] = hlp.discreteSampling(tempParticleDist, xDomain, 1)
logW = logPhi(X[:,i], y[i], sigma2[i], muAb[i], muNorm[i])
maxLogW = np.max(logW)
w = np.exp(logW-maxLogW)
logZ += maxLogW + np.log(np.sum(w)) - np.log(N)
#if math.isnan(logZ):
#print 'X: ',X[:,i]
#print 'y: ',y[i]
#print 'muAb: ',muAb[i]
#print 'muNorm: ',muNorm[i]
#print 'sig2: ',sigma2[i]
#raw_input()
w /= np.sum(w)
ancestors = hlp.resampling(w)
X[:,i] = X[ancestors,i]
## Save init to class object
self.N = N
self.C1 = C1
self.I = I
self.X = X
self.y = y
self.logZ = logZ
self.w = w
def runModular(tStart, tEnd, Np, N, M):
r"""Run the drought detection filtering algorithm (NSMC) for a specific
region.
Parameters
----------
tStart : int
Start year.
tEnd : int
End year.
Np : int
Number of particles, 1st level.
N : int
Number of particles, 2nd level.
M : int
Number of particles, 3rd level.
Returns
-------
Saves marginal posterior mean.
"""
# Model init
region = 'us'
#region = 'sahel'
if region == 'us':
X = np.zeros((Np,20,30))
xC = np.zeros((20,30),dtype=bool)
else:
X = np.zeros((Np,24,44))
xC = np.zeros((24,44),dtype=bool)
logZ = np.zeros(Np)
q = []
for i in range(Np):
q.append(nsmc.nestedSMC(t=tStart,N=N,M=M,xCond=xC))
logZ[i] = q[i].logZ
maxLZ = np.max(logZ)
w = np.exp(logZ-maxLZ)
w /= np.sum(w)
ESS = 1/np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(Np):
X[i,:,:] = q[ancestors[i]].simulate()
folder = '/data/chran60/nestedsmc/drought'
np.savetxt(folder+'/Np'+str(Np)+'_M'+str(N)+'_M'+str(M)+'_t'+str(tStart)+region+'.csv',np.mean(X,axis=0),delimiter=',')
for t in np.arange(1,tEnd-tStart+1):
print 't: ',tStart+t, ' ESS: ', ESS
q = []
for i in range(Np):
q.append(nsmc.nestedSMC(t=t+tStart,N=N,M=M,xCond=X[i,:,:]))
logZ[i] = q[i].logZ
maxLZ = np.max(logZ)
w = np.exp(logZ-maxLZ)
w /= np.sum(w)
ESS = 1/np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(Np):
X[i,:,:] = q[ancestors[i]].simulate()
np.savetxt(folder+'/Np'+str(Np)+'_M'+str(N)+'_M'+str(M)+'_t'+str(tStart+t)+region+'.csv',np.mean(X,axis=0),delimiter=',')
for t in range(T):
for i in range(N):
# j = 1
# Propagate
Xcur[i, :, 0] = a * Xprev[i, :, 0] + (
1 / np.sqrt(tauRho)) * np.random.normal(size=M)
# Weight
logW = logPhi(Xcur[i, :, 0], y[0, t])
maxLogW = np.max(logW)
w = np.exp(logW - maxLogW)
logZ[i] = maxLogW + np.log(np.sum(w)) - np.log(M)
w /= np.sum(w)
# Resample
ancestors = hlp.resampling(w)
Xprev[i, :, :] = Xprev[i, ancestors, :]
Xcur[i, :, 0] = Xcur[i, ancestors, 0]
# j = 2:d
for j in np.arange(1, d):
# Propagate
tau = tauRho + tauPsi
mu = (tauRho * a * Xprev[i, :, j] +
tauPsi * Xcur[i, :, j - 1]) / tau
Xcur[i, :,
j] = mu + (1 / np.sqrt(tau)) * np.random.normal(size=M)
# Weighting
logW = logPhi(Xcur[i, :, j], y[j, t])
maxLogW = np.max(logW)
NT = N / 2
Xcur = np.zeros((N, d))
Xprev = np.zeros((N, d))
logW = np.zeros(N)
w = np.ones(N)
ancestors = np.zeros(N)
ESS = N * np.ones(T * d)
filename = './results/d' + str(d) + '_N' + str(N) + 'tauPhi' + str(
tauPhi) + '_nipsSMC.csv'
f = open(filename, 'w')
f.close()
for t in range(T):
if ESS[t * d - 1] < NT:
ancestors = hlp.resampling(w, scheme='sys')
Xprev = Xprev[ancestors, :]
w = np.ones(N)
Xcur[:,
0] = a * Xprev[:,
0] + (1 / np.sqrt(tauRho)) * np.random.normal(size=N)
logW = logPhi(Xcur[:, 0], y[0, t])
maxLogW = np.max(logW)
w *= np.exp(logW - maxLogW)
w /= np.sum(w)
ESS[t * d] = 1 / np.sum(w**2)
for i in np.arange(1, d):
# Resampling
def __init__(self, t, N, M, xCond=None):
C1 = 0.5
C2 = 3.
# Model init
xDomain = np.arange(2)
# Load parameters
region = 'dustBowl'
#region = 'sahel'
filename = 'parameters/' + region + 'Sigma2_N35-55_W90-120_downsampled.csv'
sigma2 = np.loadtxt(filename, delimiter=',')
filename = 'parameters/' + region + 'MuAb_N35-55_W90-120_downsampled.csv'
muAb = np.loadtxt(filename, delimiter=',')
filename = 'parameters/' + region + 'MuNorm_N35-55_W90-120_downsampled.csv'
muNorm = np.loadtxt(filename, delimiter=',')
filename = 'processedData/' + region + 'Yt' + str(
t) + '_N35-55_W90-120_downsampled.csv'
Y = np.loadtxt(filename, delimiter=',')
I = Y.shape[0]
J = Y.shape[1]
# SMC init
X = np.zeros((N, I, J), dtype=bool)
ancestors = np.zeros(N)
logZ = 0.
logW = np.zeros(N)
w = np.zeros(N)
ESS = np.zeros(J)
# ---------------
# SMC
# ---------------
# SMC first iteration
params = hlp.params(I=I,
muAb=muAb[:, 0],
muNorm=muNorm[:, 0],
sigma2=sigma2[:, 0])
if xCond is not None:
q = [
nested.inner(params, Y[:, 0], M, xCond[:, 0]) for i in range(N)
]
else:
q = [nested.inner(params, Y[:, 0], M) for i in range(N)]
logW = np.array([q[i].logZ for i in range(N)])
maxLogW = np.max(logW)
w = np.exp(logW - maxLogW)
logZ = maxLogW + np.log(np.sum(w)) - np.log(N)
w /= np.sum(w)
#print w.shape
ESS[0] = 1 / np.sum(w**2)
#print 'ESS: ',ESS[0]
#print 'First logZ: ',logZ
ancestors = hlp.resampling(w)
for i in range(N):
X[i, :, 0] = q[ancestors[i]].simulate()
## SMC MAIN LOOP
for j in np.arange(1, J):
#print j
params = hlp.params(I=I,
muAb=muAb[:, j],
muNorm=muNorm[:, j],
sigma2=sigma2[:, j])
if xCond is not None:
q = [
nested.inner(params, Y[:, j], M, xCond[:, j],
X[i, :, j - 1]) for i in range(N)
]
else:
q = [
nested.inner(params, Y[:, j], M, xSpaceCond=X[i, :, j - 1])
for i in range(N)
]
logW = np.array([q[i].logZ for i in range(N)])
maxLogW = np.max(logW)
w = np.exp(logW - maxLogW)
logZ += maxLogW + np.log(np.sum(w)) - np.log(N)
#print 'j: ',j,' logZ',logZ
#print 'logW: ',logW
#print 'Y: ',Y[:,j]
w /= np.sum(w)
#print 'Max w: ',np.max(w)
ESS[j] = 1 / np.sum(w**2)
#print 'ESS: ',ESS[j]
ancestors = hlp.resampling(w)
for i in range(N):
X[i, :, j] = q[ancestors[i]].simulate()
#print 'Last logZ: ',logZ
## Save init to class object
self.N = N
self.J = J
self.I = I
self.X = X
self.logZ = logZ
self.w = w
self.xCond = xCond
self.ESS = ESS
def smc(self, order, N, NT=1.1, resamp='mult', verbose=False):
"""
SMC algorithm to estimate (log)Z of the classical XY model with
free boundary conditions.
Parameters
----------
order : 1-D array_like
The order in which to add the random variables x, flat index.
N : int
The number of particles used to estimate Z.
NT : int
Threshold for ESS-based resampling (0,1] or 1.1. Resample if ESS < NT*N (NT=1.1, resample every time)
resamp : string
Type of resampling scheme {mult, res, strat, sys}.
verbose : bool
Output changed to logZk, xMean, ESS.
Output
------
logZ : float
Estimate of (log)Z in double precision.
"""
# Init variables
nx = self.sz
ny = self.sz
logZ = np.zeros( nx*ny )
indSorted = order.argsort()
orderSorted = order[indSorted]
# SMC specific
trajectory = np.zeros( (N, len(order)) )
ancestors = np.zeros( N, np.int )
nu = np.zeros( N )
tempNu = np.zeros( N )
ess = np.zeros( len(order)-1 )
iter = 0
# -------
# SMC
# -------
# First iteration
ix, iy = hlp.unravel_index( order[0], (nx,ny) )
tempMean = 0.
tempDispersion = 0.
trajectory[:,0] = np.random.vonmises(tempMean, tempDispersion, N)
# Log-trick update of adjustment multipliers and logZ
tempDispersion = np.zeros(N)
for iSMC in range( 1, len(order) ):
# Resampling with log-trick update
nu += np.log(2 * np.pi * np.i0(tempDispersion))
nuMax = np.max(nu)
tempNu = np.exp( nu - nuMax )
c = np.sum(tempNu)
tempNu /= c
ess[iSMC-1] = 1 / (np.sum(tempNu**2))
if ess[iSMC-1] < NT*float(N):
nu = np.exp( nu - nuMax )
if iter > 0:
logZ[iter] = logZ[iter-1] + nuMax + np.log( np.sum(nu) ) - np.log(N)
else:
logZ[iter] = nuMax + np.log( np.sum(nu) ) - np.log(N)
c = np.sum(nu)
nu /= c
ancestors = hlp.resampling( nu, scheme=resamp )
nu = np.zeros( N )
trajectory[:,:iSMC] = trajectory[ancestors, :iSMC]
iter += 1
# Calculate optimal proposal and adjustment multipliers
ix, iy = hlp.unravel_index( order[iSMC], (nx,ny) )
tempMean = np.zeros( N )
tempDispersion = np.zeros( N )
if ix > 0:
tempInd = hlp.ravel_multi_index( (ix-1,iy), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
else:
tempInd = hlp.ravel_multi_index( (nx-1,iy), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
if ix < nx-1:
tempInd = hlp.ravel_multi_index( (ix+1,iy), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
else:
tempInd = hlp.ravel_multi_index( (0,iy), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
if iy > 0:
tempInd = hlp.ravel_multi_index( (ix,iy-1), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
else:
tempInd = hlp.ravel_multi_index( (ix,ny-1), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
if iy < ny-1:
tempInd = hlp.ravel_multi_index( (ix,iy+1), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
else:
tempInd = hlp.ravel_multi_index( (ix,0), (nx,ny) )
if tempInd in order[:iSMC]:
kappa = self.J
tempIndSMC = indSorted[orderSorted.searchsorted(tempInd)]
Y = tempDispersion*np.sin( -tempMean ) + kappa*np.sin( -trajectory[:,tempIndSMC] )
X = tempDispersion*np.cos( -tempMean ) + kappa*np.cos( -trajectory[:,tempIndSMC] )
tempDispersion = np.sqrt( tempDispersion**2 + kappa**2 + 2*kappa*tempDispersion*np.cos(-tempMean+trajectory[:,tempIndSMC] ) )
tempMean = -np.arctan2(Y ,X)
for iParticle in range(N):
trajectory[iParticle, iSMC] = hlp.vonmises(tempMean[iParticle], tempDispersion[iParticle])
nu += np.log(2 * np.pi * np.i0(tempDispersion))
nuMax = np.max(nu)
nu = np.exp( nu - nuMax )
logZ[iter] = logZ[iter-1] + nuMax + np.log( np.sum(nu) ) - np.log(N)
if verbose:
c = np.sum(nu)
nu /= c
trajMean = np.mean( (np.tile(nu, (len(order),1))).T*trajectory, axis=0 )
return logZ, trajMean[order].reshape( (nx,ny) ), ess
else:
return logZ[iter]
def runModular(tStart, tEnd, Np, N, M):
r"""Run the drought detection filtering algorithm (NSMC) for a specific
region.
Parameters
----------
tStart : int
Start year.
tEnd : int
End year.
Np : int
Number of particles, 1st level.
N : int
Number of particles, 2nd level.
M : int
Number of particles, 3rd level.
Returns
-------
Saves marginal posterior mean.
"""
# Model init
region = 'us'
#region = 'sahel'
if region == 'us':
X = np.zeros((Np, 20, 30))
xC = np.zeros((20, 30), dtype=bool)
else:
X = np.zeros((Np, 24, 44))
xC = np.zeros((24, 44), dtype=bool)
logZ = np.zeros(Np)
q = []
for i in range(Np):
q.append(nsmc.nestedSMC(t=tStart, N=N, M=M, xCond=xC))
logZ[i] = q[i].logZ
maxLZ = np.max(logZ)
w = np.exp(logZ - maxLZ)
w /= np.sum(w)
ESS = 1 / np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(Np):
X[i, :, :] = q[ancestors[i]].simulate()
folder = '/data/chran60/nestedsmc/drought'
np.savetxt(folder + '/Np' + str(Np) + '_M' + str(N) + '_M' + str(M) +
'_t' + str(tStart) + region + '.csv',
np.mean(X, axis=0),
delimiter=',')
for t in np.arange(1, tEnd - tStart + 1):
print 't: ', tStart + t, ' ESS: ', ESS
q = []
for i in range(Np):
q.append(nsmc.nestedSMC(t=t + tStart, N=N, M=M, xCond=X[i, :, :]))
logZ[i] = q[i].logZ
maxLZ = np.max(logZ)
w = np.exp(logZ - maxLZ)
w /= np.sum(w)
ESS = 1 / np.sum(w**2)
ancestors = hlp.resampling(w)
for i in range(Np):
X[i, :, :] = q[ancestors[i]].simulate()
np.savetxt(folder + '/Np' + str(Np) + '_M' + str(N) + '_M' + str(M) +
'_t' + str(tStart + t) + region + '.csv',
np.mean(X, axis=0),
delimiter=',')
def __init__(self, params, Y, N, xCond=None):
# Model init
d = len(Y)
def logPhi(x, y):
return -0.5 * params.tauPhi * (x - y)**2
# SMC init
if xCond is None:
xCond = np.zeros(d)
logZ = 0.
X = np.zeros((N, d))
Xa = np.zeros((N, d))
ancestors = np.zeros(N)
w = np.zeros((N, d))
W = np.zeros((N, d))
logW = np.zeros(N)
#ESS = np.zeros( d )
#NT = N/2
#resamp = 0
# i=1
X[:, 0] = params.tauRho * params.a * xCond[0] + (
1 / np.sqrt(params.tauRho)) * np.random.normal(size=N)
# Weighting
logW = logPhi(X[:, 0], Y[0])
maxLogW = np.max(logW)
w[:, 0] = np.exp(logW - maxLogW)
logZ += maxLogW + np.log(np.sum(w[:, 0])) - np.log(N)
w[:, 0] /= np.sum(w[:, 0])
ancestors = hlp.resampling(w[:, 0])
X[:, 0] = X[ancestors, 0]
Xa[:, 0] = X[:, 0]
#tempW = w[:,0] / np.sum(w[:,0])
#ESS[0] = 1/np.sum(tempW**2)
#if ESS[0] < NT:
#logZ += maxLogW + np.log(np.sum(w[:,0])) - np.log(N)
#w[:,0] /= np.sum(w[:,0])
#ancestors = hlp.resampling(w[:,0],scheme='sys')
#X[:,0] = X[ancestors,0]
#logW = np.zeros( N )
#else:
#ancestors = np.arange(N)
# i=2:d
for i in np.arange(1, d):
# Propagate
tau = params.tauRho + params.tauPsi
mu = (params.tauRho * params.a * xCond[i] +
params.tauPsi * X[:, i - 1]) / tau
X[:, i] = mu + (1 / np.sqrt(tau)) * np.random.normal(size=N)
# Weighting, Resampling
logW = logPhi(X[:, i], Y[i])
maxLogW = np.max(logW)
w[:, i] = np.exp(logW - maxLogW)
logZ += maxLogW + np.log(np.sum(w[:, i])) - np.log(N)
w[:, i] /= np.sum(w[:, i])
ancestors = hlp.resampling(w[:, i])
X[:, i] = X[ancestors, i]
Xa[:, :i] = Xa[ancestors, :i]
Xa[:, i] = X[:, i]
#tempW = w[:,i] / np.sum(w[:,i])
#ESS[i] = 1/np.sum(tempW**2)
## ESS-based Resampling
#if ESS[i] < NT or i == d-1:
#logZ += maxLogW + np.log(np.sum(w[:,i])) - np.log(N)
#w[:,i] /= np.sum(w[:,i])
#ancestors = hlp.resampling(w[:,i],scheme='sys')
#X[:,i] = X[ancestors,i]
#logW = np.zeros( N )
#else:
#ancestors = np.arange(N)
# Save init to class object
self.N = N
self.d = d
self.X = X
self.Xa = Xa
self.Y = Y
self.params = params
self.logZ = logZ
self.w = w
self.xCond = xCond
NT = N/2
Xcur = np.zeros( (N, d) )
Xprev = np.zeros( (N, d) )
logW = np.zeros(N)
w = np.ones( N )
ancestors = np.zeros( N )
ESS = N*np.ones( T*d )
filename = './results/d'+str(d)+'_N'+str(N)+'tauPhi'+str(tauPhi)+'_nipsSMC.csv'
f = open(filename, 'w')
f.close()
for t in range(T):
if ESS[t*d-1] < NT:
ancestors = hlp.resampling(w,scheme='sys')
Xprev = Xprev[ancestors,:]
w = np.ones( N )
Xcur[:, 0] = a*Xprev[:, 0] + (1/np.sqrt(tauRho))*np.random.normal(size=N)
logW = logPhi(Xcur[:,0],y[0,t])
maxLogW = np.max(logW)
w *= np.exp(logW - maxLogW)
w /= np.sum(w)
ESS[t*d] = 1/np.sum(w**2)
for i in np.arange(1,d):
# Resampling
if ESS[t*d+i-1] < NT:
ancestors = hlp.resampling(w,scheme='sys')
def runBootstrap(d, tauPhi, N, nrRuns):
r"""Run bootstrap particle filtering on high-dimensional LGSS.
Parameters
----------
d : int
State dimension.
tauPhi : float
Measurement precision.
N : int
Number of particles
nrRuns : int
Number of independent runs of the algorithm..
Returns
-------
Saves E[X] and E[X**2] estimates.
"""
a = 0.5
tauPsi = 1.
tauRho = 1.
filename = 'simulatedData/d' + str(d) + 'tauPhi' + str(tauPhi) + 'y.txt'
y = np.loadtxt(filename)
filename = 'simulatedData/d' + str(d) + 'tauPhi' + str(tauPhi) + 'P.txt'
P = np.loadtxt(filename)
P = P[:d, :d]
T = y.shape[1]
for j in range(nrRuns):
filename = './results/paper/d' + str(d) + '_N' + str(
N) + 'tauPhi' + str(tauPhi) + '_bootstraprun' + str(j + 1) + '.csv'
f = open(filename, 'w')
f.close()
xCur = np.zeros((N, d))
xPrev = np.zeros((N, d))
ancestors = np.zeros(N)
weights = np.zeros(N)
logWeights = np.zeros(N)
ESS = np.zeros(T)
xCur = np.random.multivariate_normal(np.zeros(d), P, size=N)
xPrev = xCur
# t = 1
for i in range(N):
logWeights[i] = -0.5 * tauPhi * np.sum((xCur[i, :] - y[:, 0])**2)
maxLw = np.max(logWeights)
weights = np.exp(logWeights - maxLw)
weights /= np.sum(weights)
ancestors = hlp.resampling(weights)
xCur = xCur[ancestors, :]
ESS[0] = 1 / np.sum(weights**2)
f = open(filename, 'a')
tmpVec = np.r_[1, ESS[0],
np.mean(xCur, axis=0),
np.mean(xCur**2, axis=0)]
np.savetxt(f, tmpVec.reshape((1, len(tmpVec))), delimiter=',')
f.close()
# t > 1
for t in np.arange(1, T):
# Resampling
ancestors = hlp.resampling(weights)
# Generate samples
rndSamp = np.random.multivariate_normal(np.zeros(d), P, size=N)
# Propagate
for i in range(N):
mu = tauRho * a * np.dot(P, xPrev[ancestors[i], :])
xCur[i, :] = mu + rndSamp[i, :]
logWeights[i] = -0.5 * tauPhi * np.sum(
(xCur[i, :] - y[:, t])**2)
maxLw = np.max(logWeights)
weights = np.exp(logWeights - maxLw)
weights /= np.sum(weights)
ESS[t] = 1 / np.sum(weights**2)
xPrev = xCur
f = open(filename, 'a')
tmpVec = np.r_[t + 1, ESS[t],
np.mean(xCur, axis=0),
np.mean(xCur**2, axis=0)]
np.savetxt(f, tmpVec.reshape((1, len(tmpVec))), delimiter=',')
f.close()
