predictive_mean changed to predictive_values

This commit is contained in:
Ricardo Andrade 2013-01-31 14:43:32 +00:00
parent 451ff74015
commit 9feae765dc
2 changed files with 25 additions and 66 deletions

View file

@ -19,35 +19,6 @@ class likelihood:
self.location = location
self.scale = scale
def plot2D(self,X,X_new,F_new,U=None):
"""
Predictive distribution of the fitted GP model for 2-dimensional inputs
:param X_new: The points at which to make a prediction
:param Mean_new: mean values at X_new
:param Var_new: variance values at X_new
:param X_u: input points used to train the model
:param Mean_u: mean values at X_u
:param Var_new: variance values at X_u
"""
N,D = X_new.shape
assert D == 2, 'Number of dimensions must be 2'
n = np.sqrt(N)
x1min = X_new[:,0].min()
x1max = X_new[:,0].max()
x2min = X_new[:,1].min()
x2max = X_new[:,1].max()
pb.imshow(F_new.reshape(n,n),extent=(x1min,x1max,x2max,x2min),vmin=0,vmax=1)
pb.colorbar()
C1 = np.arange(self.N)[self.Y.flatten()==1]
C2 = np.arange(self.N)[self.Y.flatten()==-1]
[pb.plot(X[i,0],X[i,1],'ro') for i in C1]
[pb.plot(X[i,0],X[i,1],'bo') for i in C2]
pb.xlim(x1min,x1max)
pb.ylim(x2min,x2max)
if U is not None:
[pb.plot(a,b,'wo') for a,b in U]
class probit(likelihood):
"""
Probit likelihood
@ -76,32 +47,23 @@ class probit(likelihood):
sigma2_hat = 1./tau_i - (phi/((tau_i**2+tau_i)*Z_hat))*(z+phi/Z_hat)
return Z_hat, mu_hat, sigma2_hat
def predictive_mean(self,mu,var):
def predictive_values(self,mu,var,all=False):
"""
Compute mean, variance, and conficence interval (percentiles 5 and 95) of the prediction
"""
mu = mu.flatten()
var = var.flatten()
return stats.norm.cdf(mu/np.sqrt(1+var))
def predictive_quantiles(self,mu,var):
#p=self.predictive_mean(mu,var)
#return p*(1-p)
raise NotImplementedError #TODO
mean = stats.norm.cdf(mu/np.sqrt(1+var))
if all:
p_05 = np.zeros([mu.size])
p_95 = np.ones([mu.size])
return mean, mean*(1-mean),p_05,p_95
else:
return mean
def _log_likelihood_gradients():
return np.zeros(0) # there are no parameters of whcih to compute the gradients
def plot(self,X,mu,var,phi,X_obs,Z=None,samples=0):
#TODO: remove me
assert X_obs.shape[1] == 1, 'Number of dimensions must be 1'
phi_var = self.predictive_var(mu,var)
gpplot(X,phi,phi_var)
if samples:
phi_samples = np.vstack([np.random.binomial(1,phi.flatten()) for s in range(samples)])
pb.plot(X,phi_samples.T,'x', alpha = 0.4, c='#3465a4' )
pb.plot(X_obs,(self.Y+1)/2,'kx',mew=1.5)
if Z is not None:
pb.plot(Z,Z*0+.5,'r|',mew=1.5,markersize=12)
pb.ylim(-0.2,1.2)
class poisson(likelihood):
"""
Poisson likelihood
@ -172,11 +134,18 @@ class poisson(likelihood):
sigma2_hat = m2 - mu_hat**2 # Second central moment
return float(Z_hat), float(mu_hat), float(sigma2_hat)
def predictive_mean(self,mu,var):
return np.exp(mu*self.scale + self.location)
def predictive_var(self,mu,var):
return predictive_mean(mu,var)
def predictive_values(self,mu,var,all=False):
"""
Compute mean, variance, and conficence interval (percentiles 5 and 95) of the prediction
"""
mean = np.exp(mu*self.scale + self.location)
if all:
tmp = stats.poisson.ppf(np.array([.05,.95]),mu)
p_05 = tmp[:,0]
p_95 = tmp[:,1]
return mean,mean,p_05,p_95
else:
return mean
def _log_likelihood_gradients():
raise NotImplementedError
@ -212,13 +181,6 @@ class gaussian(likelihood):
Z_hat = 1./np.sqrt(2*np.pi) * 1./np.sqrt(sigma**2+s**2) * np.exp(-.5*(mu-self.Y[i])**2/(sigma**2 + s**2))
return Z_hat, mu_hat, sigma2_hat
def plot1Db(self,X,X_new,F_new,U=None):
assert X.shape[1] == 1, 'Number of dimensions must be 1'
gpplot(X_new,F_new,np.zeros(X_new.shape[0]))
pb.plot(X,self.Y,'kx',mew=1.5)
if U is not None:
pb.plot(U,np.ones(U.shape[0])*self.Y.min()*.8,'r|',mew=1.5,markersize=12)
def _log_likelihood_gradients():
raise NotImplementedError
else: