Renamed StudentTpos to HalfStudentT (#1380)

* Renamed StudentTpos to HalfStudentT

* Fixed typo

* Added deprecation warning for StudentTpos

Author: Chris Fonnesbeck

pymc3/distributions/__init__.py

@@ -13,10 +13,11 @@
 from .continuous import Gamma
 from .continuous import Weibull
 from .continuous import Bound
-from .continuous import StudentTpos
+from .continuous import HalfStudentT
 from .continuous import Lognormal
 from .continuous import ChiSquared
 from .continuous import HalfNormal
+from .continuous import StudentTpos
 from .continuous import Wald
 from .continuous import Pareto
 from .continuous import InverseGamma
@@ -73,8 +74,9 @@
            'Gamma',
            'Weibull',
            'Bound',
+           'Lognormal',     
+           'HalfStudentT', 
            'StudentTpos',
-           'Lognormal',
            'ChiSquared',
            'HalfNormal',
            'Wald',

pymc3/distributions/continuous.py

@@ -10,14 +10,15 @@
 import numpy as np
 import theano.tensor as tt
 from scipy import stats
+import warnings
 
 from . import transforms
 from .dist_math import bound, logpow, gammaln, betaln, std_cdf, i0, i1
 from .distribution import Continuous, draw_values, generate_samples
 
 __all__ = ['Uniform', 'Flat', 'Normal', 'Beta', 'Exponential', 'Laplace',
            'StudentT', 'Cauchy', 'HalfCauchy', 'Gamma', 'Weibull',
-           'Bound', 'StudentTpos', 'Lognormal', 'ChiSquared', 'HalfNormal',
+           'Bound', 'HalfStudentT', 'StudentTpos', 'Lognormal', 'ChiSquared', 'HalfNormal',
            'Wald', 'Pareto', 'InverseGamma', 'ExGaussian', 'VonMises']
 
 
@@ -1106,7 +1107,12 @@ def dist(self, *args, **kwargs):
                             *args, **kwargs)
 
 
-StudentTpos = Bound(StudentT, lower=0)
+def StudentTpos(*args, **kwargs):
+    warnings.warn("StudentTpos has been deprecated. In future, use HalfStudentT instead.",
+                DeprecationWarning)
+    return HalfStudentT(*args, **kwargs)
+
+HalfStudentT = Bound(StudentT, lower=0)
 
 
 class ExGaussian(Continuous):

pymc3/tests/test_distributions.py

@@ -8,7 +8,7 @@
 from ..distributions import (DensityDist, Categorical, Multinomial, VonMises, Dirichlet,
                              MvStudentT, MvNormal, ZeroInflatedPoisson,
                              ZeroInflatedNegativeBinomial, ConstantDist, Poisson, Bernoulli, Beta,
-                             BetaBinomial, StudentTpos, StudentT, Weibull, Pareto, InverseGamma,
+                             BetaBinomial, HalfStudentT, StudentT, Weibull, Pareto, InverseGamma,
                              Gamma, Cauchy, HalfCauchy, Lognormal, Laplace, NegativeBinomial,
                              Geometric, Exponential, ExGaussian, Normal, Flat, LKJCorr, Wald,
                              ChiSquared, HalfNormal, DiscreteUniform, Bound, Uniform,
@@ -454,7 +454,7 @@ def test_weibull(self):
 
     def test_student_tpos(self):
         # TODO: this actually shouldn't pass
-        self.pymc3_matches_scipy(StudentTpos, Rplus, {'nu': Rplus, 'mu': R, 'lam': Rplus},
+        self.pymc3_matches_scipy(HalfStudentT, Rplus, {'nu': Rplus, 'mu': R, 'lam': Rplus},
                                  lambda value, nu, mu, lam: sp.t.logpdf(value, nu, mu, lam**-.5))
 
     def test_binomial(self):