def test_mvt_pdf(self):
cov3 = self.cov3
mu3 = self.mu3
mvt = MVT((0, 0), 1, 5)
assert_almost_equal(mvt.logpdf(np.array([0., 0.])),
-1.837877066409345,
decimal=15)
assert_almost_equal(mvt.pdf(np.array([0., 0.])),
0.1591549430918953,
decimal=15)
mvt.logpdf(np.array([1., 1.])) - (-3.01552989458359)
mvt1 = MVT((0, 0), 1, 1)
mvt1.logpdf(np.array([1., 1.])) - (-3.48579549941151) #decimal=16
rvs = mvt.rvs(100000)
assert_almost_equal(np.cov(rvs, rowvar=0), mvt.cov, decimal=1)
mvt31 = MVT(mu3, cov3, 1)
assert_almost_equal(mvt31.pdf(cov3), [
0.0007276818698165781, 0.0009980625182293658, 0.0027661422056214652
],
decimal=17)
mvt = MVT(mu3, cov3, 3)
assert_almost_equal(
mvt.pdf(cov3),
[0.000863777424247410, 0.001277510788307594, 0.004156314279452241],
decimal=17)
def test_mvt_pdf(self):
cov3 = self.cov3
mu3 = self.mu3
mvt = MVT((0,0), 1, 5)
assert_almost_equal(mvt.logpdf(np.array([0.,0.])), -1.837877066409345,
decimal=15)
assert_almost_equal(mvt.pdf(np.array([0.,0.])), 0.1591549430918953,
decimal=15)
mvt.logpdf(np.array([1.,1.]))-(-3.01552989458359)
mvt1 = MVT((0,0), 1, 1)
mvt1.logpdf(np.array([1.,1.]))-(-3.48579549941151) #decimal=16
rvs = mvt.rvs(100000)
assert_almost_equal(np.cov(rvs, rowvar=0), mvt.cov, decimal=1)
mvt31 = MVT(mu3, cov3, 1)
assert_almost_equal(mvt31.pdf(cov3),
[0.0007276818698165781, 0.0009980625182293658, 0.0027661422056214652],
decimal=17)
mvt = MVT(mu3, cov3, 3)
assert_almost_equal(mvt.pdf(cov3),
[0.000863777424247410, 0.001277510788307594, 0.004156314279452241],
decimal=17)
class GaussianBayes(object):
def __init__(self, priormu, nu, kappa, S, data, alpha=1, true_dist=None):
""" Initialize Gaussian distribution with data and priors
then calculate the analytic posterior """
self.true_dist = true_dist
self.data = data.copy()
self.n = data.shape[0]
self.priormu = np.asarray(priormu)
self.nu = nu
self.kappa = kappa
self.S = np.asarray(S)
self.alpha = alpha
self.D = self.data.shape[1]
self.train_analytic()
def train_analytic(self):
""" Calculating the analytic distribution posteriors given on page 15 of Lori's
Optimal Classification eq 34. """
self.nustar = self.nu + self.n
samplemean = self.data.mean(axis=0)
samplecov = np.cov(self.data.T)
self.mustar = (self.nu * self.priormu + self.n * samplemean) / (self.nu + self.n)
self.kappastar = self.kappa + self.n
self.Sstar = (
self.S
+ (self.n - 1) * samplecov
+ self.nu * self.n / (self.nu + self.n) * np.outer((samplemean - self.priormu), (samplemean - self.priormu))
)
# Now calculate effective class conditional densities from eq 55 page 21
self.fx = MVT(
self.mustar,
(self.nustar + 1) / (self.kappastar - self.D + 1) / self.nustar * self.Sstar,
self.kappastar - self.D + 1,
)
def eval_posterior(self, pts):
return self.fx.logpdf(pts)
class GaussianBayes(object):
def __init__(self, priormu, nu, kappa, S, data, alpha=1, true_dist=None):
""" Initialize Gaussian distribution with data and priors
then calculate the analytic posterior """
self.true_dist = true_dist
self.data = data.copy()
self.n = data.shape[0]
self.priormu = np.asarray(priormu)
self.nu = nu
self.kappa = kappa
self.S = np.asarray(S)
self.alpha = alpha
self.D = self.data.shape[1]
self.train_analytic()
def train_analytic(self):
""" Calculating the analytic distribution posteriors given on page 15 of Lori's
Optimal Classification eq 34. """
self.nustar = self.nu + self.n
samplemean = self.data.mean(axis=0)
samplecov = np.cov(self.data.T)
self.mustar = (self.nu * self.priormu + self.n * samplemean) \
/ (self.nu + self.n)
self.kappastar = self.kappa + self.n
self.Sstar = self.S + (self.n-1)*samplecov + self.nu*self.n/(self.nu+self.n)\
* np.outer((samplemean - self.priormu), (samplemean - self.priormu))
# Now calculate effective class conditional densities from eq 55 page 21
self.fx = MVT(
self.mustar,
(self.nustar+1)/(self.kappastar-self.D+1)/self.nustar * self.Sstar,
self.kappastar - self.D + 1)
def eval_posterior(self, pts):
return self.fx.logpdf(pts)
class Classification():
def __init__(self):
np.random.seed(1234)
self.n = 4 # Data points
self.true_mu = 0.0
self.true_sigma = 1 #di.invgamma.rvs(3)
# For G function calculation and averaging
self.grid_n = 100
low,high = -4, 4
self.gextent = (low,high)
self.grid = np.linspace(low,high,self.grid_n)
self.gavg = np.zeros(self.grid_n)
self.numgavg = 0
#self.data = di.norm.rvs(size=self.n)
self.data = np.array([0.0, -0.0, 0.5, -0.5])
assert self.data.size == self.n
######## Starting point of MCMC Run #######
self.mu = 0.0
self.sigma = 2.0
###### Bookeeping ######
self.oldmu = None
self.oldsigma = None
##### Prior Values and Confidences ######
self.priorsigma = 2
self.kappa = 1
self.priormu = 0
self.nu = 8.0
#### Calculating the Analytic solution given on page 15 of Lori's
#### Optimal Classification eq 34.
self.nustar = self.nu + self.n
samplemean = self.data.mean()
samplevar = np.cov(self.data)
self.mustar = (self.nu*self.priormu + self.n * samplemean) \
/ (self.nu + self.n)
self.kappastar = self.kappa + self.n
self.Sstar = self.priorsigma + (self.n-1)*samplevar + self.nu*self.n/(self.nu+self.nu)\
* (samplemean - self.priormu)**2
#### Now calculate effective class conditional densities from eq 55
#### page 21
#self.fx = MVT(
#self.mu0star,
#(self.nu0star+1)/(self.kappa0star-self.D+1)/self.nu0star * self.S0star,
#self.kappa0star - self.D + 1)
# So I'm pretty sure this is incorrect below, off by some scaling
# parameters
self.fx = MVT(
[self.mustar],
[(self.nustar+1)/(self.kappastar)/self.nustar * self.Sstar / 2],
self.kappastar /2 )
self.analyticfx = self.fx.logpdf(self.grid.reshape(-1,1))
def propose(self):
self.oldmu = self.mu
self.oldsigma = self.sigma
self.mu += np.random.randn()*0.1
#self.mu = np.random.randn()
self.sigma = di.invgamma.rvs(1)
return 0
def copy(self):
return (self.mu, self.sigma, di.norm.rvs(loc=self.mu, scale=self.sigma))
def reject(self):
self.mu = self.oldmu
self.sigma = self.oldsigma
def energy(self):
sum = 0.0
sum -= di.norm.logpdf(self.data, loc=self.mu, scale=self.sigma).sum()
#Now add in the priors...
sum -= log(self.sigma)*(-0.5) - self.nu/2 * (self.mu-self.priormu)**2/self.sigma
sum -= log(self.sigma)*(self.kappa+2)/(-2) - 0.5*self.priorsigma/self.sigma
return sum
def calc_gfunc(self):
return di.norm.pdf(self.grid, loc=self.mu, scale=self.sigma)
def init_db(self, db, dbsize):
pass
#dtype = [('thetas',np.double),
#('energies',np.double),
#('funcs',np.double)]
#if db == None:
#return np.zeros(dbsize, dtype=dtype)
#elif db.shape[0] != dbsize:
#return np.resize(db, dbsize)
#else:
#raise Exception("DB Not inited")
def save_to_db(self, db, theta, energy, iteration):
#func = 0.0
#db[iteration] = np.array([theta, energy, func])
global mydb
mydb.append(self.copy())
# Update G function average
self.numgavg += 1
self.gavg += (self.calc_gfunc() - self.gavg) / self.numgavg
class Classification():
def __init__(self):
np.random.seed(1234)
self.n = 4 # Data points
self.true_mu = 0.0
self.true_sigma = 1 #di.invgamma.rvs(3)
# For G function calculation and averaging
self.grid_n = 100
low, high = -4, 4
self.gextent = (low, high)
self.grid = np.linspace(low, high, self.grid_n)
self.gavg = np.zeros(self.grid_n)
self.numgavg = 0
#self.data = di.norm.rvs(size=self.n)
self.data = np.array([0.0, -0.0, 0.5, -0.5])
assert self.data.size == self.n
######## Starting point of MCMC Run #######
self.mu = 0.0
self.sigma = 2.0
###### Bookeeping ######
self.oldmu = None
self.oldsigma = None
##### Prior Values and Confidences ######
self.priorsigma = 2
self.kappa = 1
self.priormu = 0
self.nu = 8.0
#### Calculating the Analytic solution given on page 15 of Lori's
#### Optimal Classification eq 34.
self.nustar = self.nu + self.n
samplemean = self.data.mean()
samplevar = np.cov(self.data)
self.mustar = (self.nu*self.priormu + self.n * samplemean) \
/ (self.nu + self.n)
self.kappastar = self.kappa + self.n
self.Sstar = self.priorsigma + (self.n-1)*samplevar + self.nu*self.n/(self.nu+self.nu)\
* (samplemean - self.priormu)**2
#### Now calculate effective class conditional densities from eq 55
#### page 21
#self.fx = MVT(
#self.mu0star,
#(self.nu0star+1)/(self.kappa0star-self.D+1)/self.nu0star * self.S0star,
#self.kappa0star - self.D + 1)
# So I'm pretty sure this is incorrect below, off by some scaling
# parameters
self.fx = MVT([self.mustar],
[(self.nustar + 1) /
(self.kappastar) / self.nustar * self.Sstar / 2],
self.kappastar / 2)
self.analyticfx = self.fx.logpdf(self.grid.reshape(-1, 1))
def propose(self):
self.oldmu = self.mu
self.oldsigma = self.sigma
self.mu += np.random.randn() * 0.1
#self.mu = np.random.randn()
self.sigma = di.invgamma.rvs(1)
return 0
def copy(self):
return (self.mu, self.sigma, di.norm.rvs(loc=self.mu,
scale=self.sigma))
def reject(self):
self.mu = self.oldmu
self.sigma = self.oldsigma
def energy(self):
sum = 0.0
sum -= di.norm.logpdf(self.data, loc=self.mu, scale=self.sigma).sum()
#Now add in the priors...
sum -= log(self.sigma) * (-0.5) - self.nu / 2 * (
self.mu - self.priormu)**2 / self.sigma
sum -= log(self.sigma) * (self.kappa + 2) / (
-2) - 0.5 * self.priorsigma / self.sigma
return sum
def calc_gfunc(self):
return di.norm.pdf(self.grid, loc=self.mu, scale=self.sigma)
def init_db(self, db, dbsize):
pass
#dtype = [('thetas',np.double),
#('energies',np.double),
#('funcs',np.double)]
#if db == None:
#return np.zeros(dbsize, dtype=dtype)
#elif db.shape[0] != dbsize:
#return np.resize(db, dbsize)
#else:
#raise Exception("DB Not inited")
def save_to_db(self, db, theta, energy, iteration):
#func = 0.0
#db[iteration] = np.array([theta, energy, func])
global mydb
mydb.append(self.copy())
# Update G function average
self.numgavg += 1
self.gavg += (self.calc_gfunc() - self.gavg) / self.numgavg
