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predictive_mean changed to predictive_values
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2 changed files with 25 additions and 66 deletions
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@ -19,35 +19,6 @@ class likelihood:
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self.location = location
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self.scale = scale
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def plot2D(self,X,X_new,F_new,U=None):
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"""
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Predictive distribution of the fitted GP model for 2-dimensional inputs
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:param X_new: The points at which to make a prediction
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:param Mean_new: mean values at X_new
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:param Var_new: variance values at X_new
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:param X_u: input points used to train the model
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:param Mean_u: mean values at X_u
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:param Var_new: variance values at X_u
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"""
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N,D = X_new.shape
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assert D == 2, 'Number of dimensions must be 2'
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n = np.sqrt(N)
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x1min = X_new[:,0].min()
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x1max = X_new[:,0].max()
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x2min = X_new[:,1].min()
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x2max = X_new[:,1].max()
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pb.imshow(F_new.reshape(n,n),extent=(x1min,x1max,x2max,x2min),vmin=0,vmax=1)
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pb.colorbar()
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C1 = np.arange(self.N)[self.Y.flatten()==1]
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C2 = np.arange(self.N)[self.Y.flatten()==-1]
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[pb.plot(X[i,0],X[i,1],'ro') for i in C1]
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[pb.plot(X[i,0],X[i,1],'bo') for i in C2]
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pb.xlim(x1min,x1max)
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pb.ylim(x2min,x2max)
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if U is not None:
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[pb.plot(a,b,'wo') for a,b in U]
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class probit(likelihood):
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"""
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Probit likelihood
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@ -76,32 +47,23 @@ class probit(likelihood):
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sigma2_hat = 1./tau_i - (phi/((tau_i**2+tau_i)*Z_hat))*(z+phi/Z_hat)
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return Z_hat, mu_hat, sigma2_hat
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def predictive_mean(self,mu,var):
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def predictive_values(self,mu,var,all=False):
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"""
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Compute mean, variance, and conficence interval (percentiles 5 and 95) of the prediction
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"""
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mu = mu.flatten()
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var = var.flatten()
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return stats.norm.cdf(mu/np.sqrt(1+var))
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def predictive_quantiles(self,mu,var):
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#p=self.predictive_mean(mu,var)
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#return p*(1-p)
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raise NotImplementedError #TODO
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mean = stats.norm.cdf(mu/np.sqrt(1+var))
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if all:
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p_05 = np.zeros([mu.size])
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p_95 = np.ones([mu.size])
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return mean, mean*(1-mean),p_05,p_95
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else:
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return mean
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def _log_likelihood_gradients():
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return np.zeros(0) # there are no parameters of whcih to compute the gradients
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def plot(self,X,mu,var,phi,X_obs,Z=None,samples=0):
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#TODO: remove me
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assert X_obs.shape[1] == 1, 'Number of dimensions must be 1'
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phi_var = self.predictive_var(mu,var)
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gpplot(X,phi,phi_var)
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if samples:
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phi_samples = np.vstack([np.random.binomial(1,phi.flatten()) for s in range(samples)])
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pb.plot(X,phi_samples.T,'x', alpha = 0.4, c='#3465a4' )
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pb.plot(X_obs,(self.Y+1)/2,'kx',mew=1.5)
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if Z is not None:
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pb.plot(Z,Z*0+.5,'r|',mew=1.5,markersize=12)
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pb.ylim(-0.2,1.2)
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class poisson(likelihood):
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"""
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Poisson likelihood
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@ -172,11 +134,18 @@ class poisson(likelihood):
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sigma2_hat = m2 - mu_hat**2 # Second central moment
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return float(Z_hat), float(mu_hat), float(sigma2_hat)
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def predictive_mean(self,mu,var):
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return np.exp(mu*self.scale + self.location)
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def predictive_var(self,mu,var):
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return predictive_mean(mu,var)
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def predictive_values(self,mu,var,all=False):
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"""
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Compute mean, variance, and conficence interval (percentiles 5 and 95) of the prediction
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"""
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mean = np.exp(mu*self.scale + self.location)
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if all:
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tmp = stats.poisson.ppf(np.array([.05,.95]),mu)
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p_05 = tmp[:,0]
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p_95 = tmp[:,1]
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return mean,mean,p_05,p_95
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else:
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return mean
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def _log_likelihood_gradients():
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raise NotImplementedError
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@ -212,13 +181,6 @@ class gaussian(likelihood):
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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))
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return Z_hat, mu_hat, sigma2_hat
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def plot1Db(self,X,X_new,F_new,U=None):
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assert X.shape[1] == 1, 'Number of dimensions must be 1'
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gpplot(X_new,F_new,np.zeros(X_new.shape[0]))
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pb.plot(X,self.Y,'kx',mew=1.5)
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if U is not None:
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pb.plot(U,np.ones(U.shape[0])*self.Y.min()*.8,'r|',mew=1.5,markersize=12)
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def _log_likelihood_gradients():
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raise NotImplementedError
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else:
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