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GPy/GPy/kern/_src/ODE_UYC.py
mu 8b62c21e33 uyc
2014-04-29 18:08:11 +01:00

290 lines
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Python
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# Copyright (c) 2013, GPy authors (see AUTHORS.txt).
# Licensed under the BSD 3-clause license (see LICENSE.txt)
from kern import Kern
from ...core.parameterization import Param
from ...core.parameterization.transformations import Logexp
import numpy as np
from independent_outputs import index_to_slices
class ODE_UYC(Kern):
def __init__(self, input_dim, variance_U=3., variance_Y=1., lengthscale_U=1., lengthscale_Y=1., ubias =1. ,active_dims=None, name='ode_uyc'):
assert input_dim ==2, "only defined for 2 input dims"
super(ODE_UYC, self).__init__(input_dim, active_dims, name)
self.variance_Y = Param('variance_Y', variance_Y, Logexp())
self.variance_U = Param('variance_U', variance_U, Logexp())
self.lengthscale_Y = Param('lengthscale_Y', lengthscale_Y, Logexp())
self.lengthscale_U = Param('lengthscale_U', lengthscale_U, Logexp())
self.ubias = Param('ubias', ubias, Logexp())
self.add_parameters(self.variance_Y, self.variance_U, self.lengthscale_Y, self.lengthscale_U, self.ubias)
def K(self, X, X2=None):
# model : a * dy/dt + b * y = U
#lu=sqrt(3)/theta1 ly=1/theta2 theta2= a/b :thetay sigma2=1/(2ab) :sigmay
X,slices = X[:,:-1],index_to_slices(X[:,-1])
if X2 is None:
X2,slices2 = X,slices
K = np.zeros((X.shape[0], X.shape[0]))
else:
X2,slices2 = X2[:,:-1],index_to_slices(X2[:,-1])
K = np.zeros((X.shape[0], X2.shape[0]))
#stop
#rdist = X[:,0][:,None] - X2[:,0][:,None].T
rdist = X - X2.T
ly=1/self.lengthscale_Y
lu=np.sqrt(3)/self.lengthscale_U
#iu=self.input_lengthU #dimention of U
Vu=self.variance_U
Vy=self.variance_Y
#Vy=ly/2
#stop
# kernel for kuu matern3/2
kuu = lambda dist:Vu * (1 + lu* np.abs(dist)) * np.exp(-lu * np.abs(dist)) +self.ubias
# kernel for kyy
k1 = lambda dist:np.exp(-ly*np.abs(dist))*(2*lu+ly)/(lu+ly)**2
k2 = lambda dist:(np.exp(-lu*dist)*(ly-2*lu+lu*ly*dist-lu**2*dist) + np.exp(-ly*dist)*(2*lu-ly) ) / (ly-lu)**2
k3 = lambda dist:np.exp(-lu*dist) * ( (1+lu*dist)/(lu+ly) + (lu)/(lu+ly)**2 )
kyy = lambda dist:Vu*Vy*(k1(dist) + k2(dist) + k3(dist))
# cross covariance function
kyu3 = lambda dist:np.exp(-lu*dist)/(lu+ly)*(1+lu*(dist+1/(lu+ly)))
#kyu3 = lambda dist: 0
k1cros = lambda dist:np.exp(ly*dist)/(lu-ly) * ( 1- np.exp( (lu-ly)*dist) + lu* ( dist*np.exp( (lu-ly)*dist ) + (1- np.exp( (lu-ly)*dist ) ) /(lu-ly) ) )
#k1cros = lambda dist:0
k2cros = lambda dist:np.exp(ly*dist)*( 1/(lu+ly) + lu/(lu+ly)**2 )
#k2cros = lambda dist:0
Vyu=np.sqrt(Vy*ly*2)
# cross covariance kuy
kuyp = lambda dist:Vu*Vyu*(kyu3(dist)) #t>0 kuy
kuyn = lambda dist:Vu*Vyu*(k1cros(dist)+k2cros(dist)) #t<0 kuy
# cross covariance kyu
kyup = lambda dist:Vu*Vyu*(k1cros(-dist)+k2cros(-dist)) #t>0 kyu
kyun = lambda dist:Vu*Vyu*(kyu3(-dist)) #t<0 kyu
for i, s1 in enumerate(slices):
for j, s2 in enumerate(slices2):
for ss1 in s1:
for ss2 in s2:
if i==0 and j==0:
K[ss1,ss2] = kuu(np.abs(rdist[ss1,ss2]))
elif i==0 and j==1:
#K[ss1,ss2]= np.where( rdist[ss1,ss2]>0 , kuyp(np.abs(rdist[ss1,ss2])), kuyn(np.abs(rdist[ss1,ss2]) ) )
K[ss1,ss2]= np.where( rdist[ss1,ss2]>0 , kuyp(rdist[ss1,ss2]), kuyn(rdist[ss1,ss2] ) )
elif i==1 and j==1:
K[ss1,ss2] = kyy(np.abs(rdist[ss1,ss2]))
else:
#K[ss1,ss2]= 0
#K[ss1,ss2]= np.where( rdist[ss1,ss2]>0 , kyup(np.abs(rdist[ss1,ss2])), kyun(np.abs(rdist[ss1,ss2]) ) )
K[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , kyup(rdist[ss1,ss2]), kyun(rdist[ss1,ss2] ) )
return K
def Kdiag(self, X):
"""Compute the diagonal of the covariance matrix associated to X."""
Kdiag = np.zeros(X.shape[0])
ly=1/self.lengthscale_Y
lu=np.sqrt(3)/self.lengthscale_U
Vu = self.variance_U
Vy=self.variance_Y
k1 = (2*lu+ly)/(lu+ly)**2
k2 = (ly-2*lu + 2*lu-ly ) / (ly-lu)**2
k3 = 1/(lu+ly) + (lu)/(lu+ly)**2
slices = index_to_slices(X[:,-1])
for i, ss1 in enumerate(slices):
for s1 in ss1:
if i==0:
Kdiag[s1]+= self.variance_U + self.ubias
elif i==1:
Kdiag[s1]+= Vu*Vy*(k1+k2+k3)
else:
raise ValueError, "invalid input/output index"
#Kdiag[slices[0][0]]+= self.variance_U #matern32 diag
#Kdiag[slices[1][0]]+= self.variance_U*self.variance_Y*(k1+k2+k3) # diag
return Kdiag
def update_gradients_full(self, dL_dK, X, X2=None):
"""derivative of the covariance matrix with respect to the parameters."""
X,slices = X[:,:-1],index_to_slices(X[:,-1])
if X2 is None:
X2,slices2 = X,slices
else:
X2,slices2 = X2[:,:-1],index_to_slices(X2[:,-1])
#rdist = X[:,0][:,None] - X2[:,0][:,None].T
rdist = X - X2.T
ly=1/self.lengthscale_Y
lu=np.sqrt(3)/self.lengthscale_U
Vu=self.variance_U
Vy=self.variance_Y
Vyu = np.sqrt(Vy*ly*2)
dVdly = 0.5/np.sqrt(ly)*np.sqrt(2*Vy)
dVdVy = 0.5/np.sqrt(Vy)*np.sqrt(2*ly)
rd=rdist.shape[0]
dktheta1 = np.zeros([rd,rd])
dktheta2 = np.zeros([rd,rd])
dkUdvar = np.zeros([rd,rd])
dkYdvar = np.zeros([rd,rd])
dkdubias = np.zeros([rd,rd])
# dk dtheta for UU
UUdtheta1 = lambda dist: np.exp(-lu* dist)*dist + (-dist)*np.exp(-lu* dist)*(1+lu*dist)
UUdtheta2 = lambda dist: 0
#UUdvar = lambda dist: (1 + lu*dist)*np.exp(-lu*dist)
UUdvar = lambda dist: (1 + lu* np.abs(dist)) * np.exp(-lu * np.abs(dist))
# dk dtheta for YY
dk1theta1 = lambda dist: np.exp(-ly*dist)*2*(-lu)/(lu+ly)**3
dk2theta1 = lambda dist: (1.0)*(
np.exp(-lu*dist)*dist*(-ly+2*lu-lu*ly*dist+dist*lu**2)*(ly-lu)**(-2) + np.exp(-lu*dist)*(-2+ly*dist-2*dist*lu)*(ly-lu)**(-2)
+np.exp(-dist*lu)*(ly-2*lu+ly*lu*dist-dist*lu**2)*2*(ly-lu)**(-3)
+np.exp(-dist*ly)*2*(ly-lu)**(-2)
+np.exp(-dist*ly)*2*(2*lu-ly)*(ly-lu)**(-3)
)
dk3theta1 = lambda dist: np.exp(-dist*lu)*(lu+ly)**(-2)*((2*lu+ly+dist*lu**2+lu*ly*dist)*(-dist-2/(lu+ly))+2+2*lu*dist+ly*dist)
#dktheta1 = lambda dist: self.variance_U*self.variance_Y*(dk1theta1+dk2theta1+dk3theta1)
dk1theta2 = lambda dist: np.exp(-ly*dist) * ((lu+ly)**(-2)) * ( (-dist)*(2*lu+ly) + 1 + (-2)*(2*lu+ly)/(lu+ly) )
dk2theta2 =lambda dist: 1*(
np.exp(-dist*lu)*(ly-lu)**(-2) * ( 1+lu*dist+(-2)*(ly-2*lu+lu*ly*dist-dist*lu**2)*(ly-lu)**(-1) )
+np.exp(-dist*ly)*(ly-lu)**(-2) * ( (-dist)*(2*lu-ly) -1+(2*lu-ly)*(-2)*(ly-lu)**(-1) )
)
dk3theta2 = lambda dist: np.exp(-dist*lu) * (-3*lu-ly-dist*lu**2-lu*ly*dist)/(lu+ly)**3
#dktheta2 = lambda dist: self.variance_U*self.variance_Y*(dk1theta2 + dk2theta2 +dk3theta2)
# kyy kernel
k1 = lambda dist: np.exp(-ly*dist)*(2*lu+ly)/(lu+ly)**2
k2 = lambda dist: (np.exp(-lu*dist)*(ly-2*lu+lu*ly*dist-lu**2*dist) + np.exp(-ly*dist)*(2*lu-ly) ) / (ly-lu)**2
k3 = lambda dist: np.exp(-lu*dist) * ( (1+lu*dist)/(lu+ly) + (lu)/(lu+ly)**2 )
#dkdvar = k1+k2+k3
# cross covariance function
kyu3 = lambda dist:np.exp(-lu*dist)/(lu+ly)*(1+lu*(dist+1/(lu+ly)))
k1cros = lambda dist:np.exp(ly*dist)/(lu-ly) * ( 1- np.exp( (lu-ly)*dist) + lu* ( dist*np.exp( (lu-ly)*dist ) + (1- np.exp( (lu-ly)*dist ) ) /(lu-ly) ) )
k2cros = lambda dist:np.exp(ly*dist)*( 1/(lu+ly) + lu/(lu+ly)**2 )
# cross covariance kuy
kuyp = lambda dist:(kyu3(dist)) #t>0 kuy
kuyn = lambda dist:(k1cros(dist)+k2cros(dist)) #t<0 kuy
# cross covariance kyu
kyup = lambda dist:(k1cros(-dist)+k2cros(-dist)) #t>0 kyu
kyun = lambda dist:(kyu3(-dist)) #t<0 kyu
# dk dtheta for UY
dkyu3dtheta2 = lambda dist: np.exp(-lu*dist) * ( (-1)*(lu+ly)**(-2)*(1+lu*dist+lu*(lu+ly)**(-1)) + (lu+ly)**(-1)*(-lu)*(lu+ly)**(-2) )
dkyu3dtheta1 = lambda dist: np.exp(-lu*dist)*(lu+ly)**(-1)* ( (-dist)*(1+dist*lu+lu*(lu+ly)**(-1)) -\
(lu+ly)**(-1)*(1+dist*lu+lu*(lu+ly)**(-1)) +dist+(lu+ly)**(-1)-lu*(lu+ly)**(-2) )
dkcros2dtheta1 = lambda dist: np.exp(ly*dist)* ( -(ly+lu)**(-2) + (ly+lu)**(-2) + (-2)*lu*(lu+ly)**(-3) )
dkcros2dtheta2 = lambda dist: np.exp(ly*dist)*dist* ( (ly+lu)**(-1) + lu*(lu+ly)**(-2) ) + \
np.exp(ly*dist)*( -(lu+ly)**(-2) + lu*(-2)*(lu+ly)**(-3) )
dkcros1dtheta1 = lambda dist: np.exp(ly*dist)*( -(lu-ly)**(-2)*( 1-np.exp((lu-ly)*dist) + lu*dist*np.exp((lu-ly)*dist)+ \
lu*(1-np.exp((lu-ly)*dist))/(lu-ly) ) + (lu-ly)**(-1)*( -np.exp( (lu-ly)*dist )*dist + dist*np.exp( (lu-ly)*dist)+\
lu*dist**2*np.exp((lu-ly)*dist)+(1-np.exp((lu-ly)*dist))/(lu-ly) - lu*np.exp((lu-ly)*dist)*dist/(lu-ly) -\
lu*(1-np.exp((lu-ly)*dist))/(lu-ly)**2 ) )
dkcros1dtheta2 = lambda t: np.exp(ly*t)*t/(lu-ly)*( 1-np.exp((lu-ly)*t) +lu*t*np.exp((lu-ly)*t)+\
lu*(1-np.exp((lu-ly)*t))/(lu-ly) )+\
np.exp(ly*t)/(lu-ly)**2* ( 1-np.exp((lu-ly)*t) +lu*t*np.exp((lu-ly)*t) + lu*( 1-np.exp((lu-ly)*t) )/(lu-ly) )+\
np.exp(ly*t)/(lu-ly)*( np.exp((lu-ly)*t)*t -lu*t*t*np.exp((lu-ly)*t) +lu*t*np.exp((lu-ly)*t)/(lu-ly)+\
lu*( 1-np.exp((lu-ly)*t) )/(lu-ly)**2 )
dkuypdtheta1 = lambda dist:(dkyu3dtheta1(dist)) #t>0 kuy
dkuyndtheta1 = lambda dist:(dkcros1dtheta1(dist)+dkcros2dtheta1(dist)) #t<0 kuy
# cross covariance kyu
dkyupdtheta1 = lambda dist:(dkcros1dtheta1(-dist)+dkcros2dtheta1(-dist)) #t>0 kyu
dkyundtheta1 = lambda dist:(dkyu3dtheta1(-dist)) #t<0 kyu
dkuypdtheta2 = lambda dist:(dkyu3dtheta2(dist)) #t>0 kuy
dkuyndtheta2 = lambda dist:(dkcros1dtheta2(dist)+dkcros2dtheta2(dist)) #t<0 kuy
# cross covariance kyu
dkyupdtheta2 = lambda dist:(dkcros1dtheta2(-dist)+dkcros2dtheta2(-dist)) #t>0 kyu
dkyundtheta2 = lambda dist:(dkyu3dtheta2(-dist)) #t<0 kyu
for i, s1 in enumerate(slices):
for j, s2 in enumerate(slices2):
for ss1 in s1:
for ss2 in s2:
if i==0 and j==0:
#target[ss1,ss2] = kuu(np.abs(rdist[ss1,ss2]))
dktheta1[ss1,ss2] = Vu*UUdtheta1(np.abs(rdist[ss1,ss2]))
dktheta2[ss1,ss2] = 0
dkUdvar[ss1,ss2] = UUdvar(np.abs(rdist[ss1,ss2]))
dkYdvar[ss1,ss2] = 0
dkdubias[ss1,ss2] = 1
elif i==0 and j==1:
########target[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , kuyp(np.abs(rdist[ss1,ss2])), kuyn(np.abs(rdist[s1[0],s2[0]]) ) )
#np.where( rdist[ss1,ss2]>0 , kuyp(np.abs(rdist[ss1,ss2])), kuyn(np.abs(rdist[s1[0],s2[0]]) ) )
#dktheta1[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , self.variance_U*self.variance_Y*dkcrtheta1(np.abs(rdist[ss1,ss2])) ,self.variance_U*self.variance_Y*(dk1theta1(np.abs(rdist[ss1,ss2]))+dk2theta1(np.abs(rdist[ss1,ss2]))) )
#dktheta2[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , self.variance_U*self.variance_Y*dkcrtheta2(np.abs(rdist[ss1,ss2])) ,self.variance_U*self.variance_Y*(dk1theta2(np.abs(rdist[ss1,ss2]))+dk2theta2(np.abs(rdist[ss1,ss2]))) )
dktheta1[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*Vyu*dkuypdtheta1(rdist[ss1,ss2]),Vu*Vyu*dkuyndtheta1(rdist[ss1,ss2]) )
dkUdvar[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vyu*kuyp(rdist[ss1,ss2]), Vyu* kuyn(rdist[ss1,ss2]) )
dktheta2[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*Vyu*dkuypdtheta2(rdist[ss1,ss2])+Vu*dVdly*kuyp(rdist[ss1,ss2]),Vu*Vyu*dkuyndtheta2(rdist[ss1,ss2])+Vu*dVdly*kuyn(rdist[ss1,ss2]) )
dkYdvar[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*dVdVy*kuyp(rdist[ss1,ss2]), Vu*dVdVy* kuyn(rdist[ss1,ss2]) )
dkdubias[ss1,ss2] = 0
elif i==1 and j==1:
#target[ss1,ss2] = kyy(np.abs(rdist[ss1,ss2]))
dktheta1[ss1,ss2] = self.variance_U*self.variance_Y*(dk1theta1(np.abs(rdist[ss1,ss2]))+dk2theta1(np.abs(rdist[ss1,ss2]))+dk3theta1(np.abs(rdist[ss1,ss2])))
dktheta2[ss1,ss2] = self.variance_U*self.variance_Y*(dk1theta2(np.abs(rdist[ss1,ss2])) + dk2theta2(np.abs(rdist[ss1,ss2])) +dk3theta2(np.abs(rdist[ss1,ss2])))
dkUdvar[ss1,ss2] = self.variance_Y*(k1(np.abs(rdist[ss1,ss2]))+k2(np.abs(rdist[ss1,ss2]))+k3(np.abs(rdist[ss1,ss2])) )
dkYdvar[ss1,ss2] = self.variance_U*(k1(np.abs(rdist[ss1,ss2]))+k2(np.abs(rdist[ss1,ss2]))+k3(np.abs(rdist[ss1,ss2])) )
dkdubias[ss1,ss2] = 0
else:
#######target[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , kyup(np.abs(rdist[ss1,ss2])), kyun(np.abs(rdist[s1[0],s2[0]]) ) )
#dktheta1[ss1,ss2] = np.where( rdist[ss1,ss2]>0 ,self.variance_U*self.variance_Y*(dk1theta1(np.abs(rdist[ss1,ss2]))+dk2theta1(np.abs(rdist[ss1,ss2]))) , self.variance_U*self.variance_Y*dkcrtheta1(np.abs(rdist[ss1,ss2])) )
#dktheta2[ss1,ss2] = np.where( rdist[ss1,ss2]>0 ,self.variance_U*self.variance_Y*(dk1theta2(np.abs(rdist[ss1,ss2]))+dk2theta2(np.abs(rdist[ss1,ss2]))) , self.variance_U*self.variance_Y*dkcrtheta2(np.abs(rdist[ss1,ss2])) )
dktheta1[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*Vyu*dkyupdtheta1(rdist[ss1,ss2]),Vu*Vyu*dkyundtheta1(rdist[ss1,ss2]) )
dkUdvar[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vyu*kyup(rdist[ss1,ss2]),Vyu*kyun(rdist[ss1,ss2]))
dktheta2[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*Vyu*dkyupdtheta2(rdist[ss1,ss2])+Vu*dVdly*kyup(rdist[ss1,ss2]),Vu*Vyu*dkyundtheta2(rdist[ss1,ss2])+Vu*dVdly*kyun(rdist[ss1,ss2]) )
dkYdvar[ss1,ss2] = np.where( rdist[ss1,ss2]>0 , Vu*dVdVy*kyup(rdist[ss1,ss2]), Vu*dVdVy*kyun(rdist[ss1,ss2]))
dkdubias[ss1,ss2] = 0
#stop
self.variance_U.gradient = np.sum(dkUdvar * dL_dK) # Vu
self.variance_Y.gradient = np.sum(dkYdvar * dL_dK) # Vy
self.lengthscale_U.gradient = np.sum(dktheta1*(-np.sqrt(3)*self.lengthscale_U**(-2))* dL_dK) #lu
self.lengthscale_Y.gradient = np.sum(dktheta2*(-self.lengthscale_Y**(-2)) * dL_dK) #ly
self.ubias.gradient = np.sum(dkdubias * dL_dK)
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