sympy_stats.diff

diff --git a/sympy/stats/sampling/tests/test_sample_continuous_rv.py b/sympy/stats/sampling/tests/test_sample_continuous_rv.py
index 7f13b4061e..46993145cb 100644
--- a/sympy/stats/sampling/tests/test_sample_continuous_rv.py
+++ b/sympy/stats/sampling/tests/test_sample_continuous_rv.py
@@ -1,6 +1,7 @@
+from sympy import exp, Interval, oo, Symbol
 from sympy.external import import_module
 from sympy.stats import Beta, Chi, Normal, Gamma, Exponential, LogNormal, Pareto, ChiSquared, Uniform, sample, \
-    BetaPrime, Cauchy, GammaInverse, GaussianInverse, StudentT
+    BetaPrime, Cauchy, GammaInverse, GaussianInverse, StudentT, Weibull, density, ContinuousRV
 from sympy.testing.pytest import skip, ignore_warnings, raises
 
 
@@ -92,3 +93,91 @@ def test_sample_pymc3():
                     assert sam in X.pspace.domain.set
             raises(NotImplementedError,
                    lambda: next(sample(Chi("C", 1), library='pymc3')))
+
+
+def test_sampling_gamma_inverse():
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy not installed. Abort tests for sampling of gamma inverse.')
+    X = GammaInverse("x", 1, 1)
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        assert next(sample(X)) in X.pspace.domain.set
+
+
+def test_lognormal_sampling():
+    # Right now, only density function and sampling works
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy is not installed. Abort tests')
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        for i in range(3):
+            X = LogNormal('x', i, 1)
+            assert next(sample(X)) in X.pspace.domain.set
+
+    size = 5
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        samps = next(sample(X, size=size))
+        for samp in samps:
+            assert samp in X.pspace.domain.set
+
+
+def test_sampling_gaussian_inverse():
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy not installed. Abort tests for sampling of Gaussian inverse.')
+    X = GaussianInverse("x", 1, 1)
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        assert next(sample(X, library='scipy')) in X.pspace.domain.set
+
+
+def test_prefab_sampling():
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy is not installed. Abort tests')
+    N = Normal('X', 0, 1)
+    L = LogNormal('L', 0, 1)
+    E = Exponential('Ex', 1)
+    P = Pareto('P', 1, 3)
+    W = Weibull('W', 1, 1)
+    U = Uniform('U', 0, 1)
+    B = Beta('B', 2, 5)
+    G = Gamma('G', 1, 3)
+
+    variables = [N, L, E, P, W, U, B, G]
+    niter = 10
+    size = 5
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        for var in variables:
+            for _ in range(niter):
+                assert next(sample(var)) in var.pspace.domain.set
+                samps = next(sample(var, size=size))
+                for samp in samps:
+                    assert samp in var.pspace.domain.set
+
+
+def test_sample_continuous():
+    z = Symbol('z')
+    Z = ContinuousRV(z, exp(-z), set=Interval(0, oo))
+    assert density(Z)(-1) == 0
+
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy is not installed. Abort tests')
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        assert next(sample(Z)) in Z.pspace.domain.set
+    sym, val = list(Z.pspace.sample().items())[0]
+    assert sym == Z and val in Interval(0, oo)
+
+    libraries = ['scipy', 'numpy', 'pymc3']
+    for lib in libraries:
+        try:
+            imported_lib = import_module(lib)
+            if imported_lib:
+                s0, s1, s2 = [], [], []
+                s0 = list(sample(Z, numsamples=10, library=lib, seed=0))
+                s1 = list(sample(Z, numsamples=10, library=lib, seed=0))
+                s2 = list(sample(Z, numsamples=10, library=lib, seed=1))
+                assert s0 == s1
+                assert s1 != s2
+        except NotImplementedError:
+            continue
diff --git a/sympy/stats/sampling/tests/test_sample_discrete_rv.py b/sympy/stats/sampling/tests/test_sample_discrete_rv.py
index ed6c64af78..f20b1633e2 100644
--- a/sympy/stats/sampling/tests/test_sample_discrete_rv.py
+++ b/sympy/stats/sampling/tests/test_sample_discrete_rv.py
@@ -1,7 +1,7 @@
 from sympy import S, Symbol
 from sympy.external import import_module
 from sympy.stats import Geometric, Poisson, Zeta, sample, Skellam, DiscreteRV, Logarithmic, NegativeBinomial, YuleSimon
-from sympy.testing.pytest import skip, ignore_warnings, raises
+from sympy.testing.pytest import skip, ignore_warnings, raises, slow
 
 
 def test_sample_numpy():
@@ -77,3 +77,29 @@ def test_sample_pymc3():
                     assert sam in X.pspace.domain.set
             raises(NotImplementedError,
                    lambda: next(sample(Skellam('S', 1, 1), library='pymc3')))
+
+@slow
+def test_sample_discrete():
+    X = Geometric('X', S.Half)
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy not installed. Abort tests')
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        assert next(sample(X)) in X.pspace.domain.set
+        samps = next(sample(X, size=2)) # This takes long time if ran without scipy
+        for samp in samps:
+            assert samp in X.pspace.domain.set
+
+    libraries = ['scipy', 'numpy', 'pymc3']
+    for lib in libraries:
+        try:
+            imported_lib = import_module(lib)
+            if imported_lib:
+                s0, s1, s2 = [], [], []
+                s0 = list(sample(X, numsamples=10, library=lib, seed=0))
+                s1 = list(sample(X, numsamples=10, library=lib, seed=0))
+                s2 = list(sample(X, numsamples=10, library=lib, seed=1))
+                assert s0 == s1
+                assert s1 != s2
+        except NotImplementedError:
+            continue
diff --git a/sympy/stats/sampling/tests/test_sample_finite_rv.py b/sympy/stats/sampling/tests/test_sample_finite_rv.py
index 41019cbbcb..c2e6aba6fe 100644
--- a/sympy/stats/sampling/tests/test_sample_finite_rv.py
+++ b/sympy/stats/sampling/tests/test_sample_finite_rv.py
@@ -4,6 +4,13 @@
     Rademacher
 from sympy.testing.pytest import skip, ignore_warnings, raises
 
+def test_given_sample():
+    X = Die('X', 6)
+    scipy = import_module('scipy')
+    if not scipy:
+        skip('Scipy is not installed. Abort tests')
+    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
+        assert next(sample(X, X > 5)) == 6
 
 def test_sample_numpy():
     distribs_numpy = [
diff --git a/sympy/stats/tests/test_continuous_rv.py b/sympy/stats/tests/test_continuous_rv.py
index f9d79d1340..e26edb766d 100644
--- a/sympy/stats/tests/test_continuous_rv.py
+++ b/sympy/stats/tests/test_continuous_rv.py
@@ -11,7 +11,7 @@
 from sympy.sets.sets import Intersection, FiniteSet
 from sympy.stats import (P, E, where, density, variance, covariance, skewness, kurtosis, median,
                          given, pspace, cdf, characteristic_function, moment_generating_function,
-                         ContinuousRV, sample, Arcsin, Benini, Beta, BetaNoncentral, BetaPrime,
+                         ContinuousRV, Arcsin, Benini, Beta, BetaNoncentral, BetaPrime,
                          Cauchy, Chi, ChiSquared, ChiNoncentral, Dagum, Erlang, ExGaussian,
                          Exponential, ExponentialPower, FDistribution, FisherZ, Frechet, Gamma,
                          GammaInverse, Gompertz, Gumbel, Kumaraswamy, Laplace, Levy, Logistic, LogCauchy,
@@ -321,33 +321,6 @@ def test_moment_generating_function():
         besseli(0, 1)
 
 
-def test_sample_continuous():
-    Z = ContinuousRV(z, exp(-z), set=Interval(0, oo))
-    assert density(Z)(-1) == 0
-
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy is not installed. Abort tests')
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        assert next(sample(Z)) in Z.pspace.domain.set
-    sym, val = list(Z.pspace.sample().items())[0]
-    assert sym == Z and val in Interval(0, oo)
-
-    libraries = ['scipy', 'numpy', 'pymc3']
-    for lib in libraries:
-        try:
-            imported_lib = import_module(lib)
-            if imported_lib:
-                s0, s1, s2 = [], [], []
-                s0 = list(sample(Z, numsamples=10, library=lib, seed=0))
-                s1 = list(sample(Z, numsamples=10, library=lib, seed=0))
-                s2 = list(sample(Z, numsamples=10, library=lib, seed=1))
-                assert s0 == s1
-                assert s1 != s2
-        except NotImplementedError:
-            continue
-
-
 def test_ContinuousRV():
     pdf = sqrt(2)*exp(-x**2/2)/(2*sqrt(pi))  # Normal distribution
     # X and Y should be equivalent
@@ -777,14 +750,6 @@ def test_gamma_inverse():
             * besselk(a, 2*sqrt(b)*sqrt(-I*x))/gamma(a)
     raises(NotImplementedError, lambda: moment_generating_function(X))
 
-def test_sampling_gamma_inverse():
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy not installed. Abort tests for sampling of gamma inverse.')
-    X = GammaInverse("x", 1, 1)
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        assert next(sample(X)) in X.pspace.domain.set
-
 def test_gompertz():
     b = Symbol("b", positive=True)
     eta = Symbol("eta", positive=True)
@@ -924,20 +889,6 @@ def test_lognormal():
     #assert E(X) == exp(mean+std**2/2)
     #assert variance(X) == (exp(std**2)-1) * exp(2*mean + std**2)
 
-    # Right now, only density function and sampling works
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy is not installed. Abort tests')
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        for i in range(3):
-            X = LogNormal('x', i, 1)
-            assert next(sample(X)) in X.pspace.domain.set
-
-    size = 5
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        samps = next(sample(X, size=size))
-        for samp in samps:
-            assert samp in X.pspace.domain.set
     # The sympy integrator can't do this too well
     #assert E(X) ==
     raises(NotImplementedError, lambda: moment_generating_function(X))
@@ -1052,14 +1003,6 @@ def test_gaussian_inverse():
     b = symbols('b', nonpositive=True)
     raises(ValueError, lambda: GaussianInverse('x', a, b))
 
-def test_sampling_gaussian_inverse():
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy not installed. Abort tests for sampling of Gaussian inverse.')
-    X = GaussianInverse("x", 1, 1)
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        assert next(sample(X, library='scipy')) in X.pspace.domain.set
-
 def test_pareto():
     xm, beta = symbols('xm beta', positive=True)
     alpha = beta + 5
@@ -1343,30 +1286,6 @@ def test_wignersemicircle():
            Piecewise((2*besselj(1, R*x)/(R*x), Ne(x, 0)), (1, True))
 
 
-def test_prefab_sampling():
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy is not installed. Abort tests')
-    N = Normal('X', 0, 1)
-    L = LogNormal('L', 0, 1)
-    E = Exponential('Ex', 1)
-    P = Pareto('P', 1, 3)
-    W = Weibull('W', 1, 1)
-    U = Uniform('U', 0, 1)
-    B = Beta('B', 2, 5)
-    G = Gamma('G', 1, 3)
-
-    variables = [N, L, E, P, W, U, B, G]
-    niter = 10
-    size = 5
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        for var in variables:
-            for _ in range(niter):
-                assert next(sample(var)) in var.pspace.domain.set
-                samps = next(sample(var, size=size))
-                for samp in samps:
-                    assert samp in var.pspace.domain.set
-
 def test_input_value_assertions():
     a, b = symbols('a b')
     p, q = symbols('p q', positive=True)
diff --git a/sympy/stats/tests/test_discrete_rv.py b/sympy/stats/tests/test_discrete_rv.py
index 56304da869..e4a693ec20 100644
--- a/sympy/stats/tests/test_discrete_rv.py
+++ b/sympy/stats/tests/test_discrete_rv.py
@@ -12,7 +12,6 @@
                                    FlorySchulz, Poisson, Geometric, Hermite, Logarithmic,
                                     NegativeBinomial, Skellam, YuleSimon, Zeta,
                                     DiscreteRV)
-from sympy.stats.rv import sample
 from sympy.testing.pytest import slow, nocache_fail, raises, skip, ignore_warnings
 from sympy.external import import_module
 from sympy.stats.symbolic_probability import Expectation
@@ -152,32 +151,6 @@ def test_zeta():
         zeta(s) * zeta(s-2) - zeta(s-1)**2) / zeta(s)**2
 
 
-@slow
-def test_sample_discrete():
-    X = Geometric('X', S.Half)
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy not installed. Abort tests')
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        assert next(sample(X)) in X.pspace.domain.set
-        samps = next(sample(X, size=2)) # This takes long time if ran without scipy
-        for samp in samps:
-            assert samp in X.pspace.domain.set
-
-    libraries = ['scipy', 'numpy', 'pymc3']
-    for lib in libraries:
-        try:
-            imported_lib = import_module(lib)
-            if imported_lib:
-                s0, s1, s2 = [], [], []
-                s0 = list(sample(X, numsamples=10, library=lib, seed=0))
-                s1 = list(sample(X, numsamples=10, library=lib, seed=0))
-                s2 = list(sample(X, numsamples=10, library=lib, seed=1))
-                assert s0 == s1
-                assert s1 != s2
-        except NotImplementedError:
-            continue
-
 def test_discrete_probability():
     X = Geometric('X', Rational(1, 5))
     Y = Poisson('Y', 4)
diff --git a/sympy/stats/tests/test_finite_rv.py b/sympy/stats/tests/test_finite_rv.py
index 08cdc38845..644eedde14 100644
--- a/sympy/stats/tests/test_finite_rv.py
+++ b/sympy/stats/tests/test_finite_rv.py
@@ -5,7 +5,7 @@
 from sympy.matrices import Matrix
 from sympy.stats import (DiscreteUniform, Die, Bernoulli, Coin, Binomial, BetaBinomial,
                          Hypergeometric, Rademacher, IdealSoliton, RobustSoliton, P, E, variance,
-                         covariance, skewness, sample, density, where, FiniteRV, pspace, cdf,
+                         covariance, skewness, density, where, FiniteRV, pspace, cdf,
                          correlation, moment, cmoment, smoment, characteristic_function,
                          moment_generating_function, quantile,  kurtosis, median, coskewness)
 from sympy.stats.frv_types import DieDistribution, BinomialDistribution, \
@@ -146,11 +146,6 @@ def test_given():
     X = Die('X', 6)
     assert density(X, X > 5) == {S(6): S.One}
     assert where(X > 2, X > 5).as_boolean() == Eq(X.symbol, 6)
-    scipy = import_module('scipy')
-    if not scipy:
-        skip('Scipy is not installed. Abort tests')
-    with ignore_warnings(UserWarning): ### TODO: Restore tests once warnings are removed
-        assert next(sample(X, X > 5)) == 6
 
 
 def test_domains():