only Caucy and Logistic - saving lognormal for another PR

Author: seuabeia

pymc/distributions/continuous.py

@@ -1714,22 +1714,12 @@ def logcdf(value, mu, sigma):
             -np.inf,
             normal_lcdf(mu, sigma, pt.log(value)),
         )
-
         return check_parameters(
             res,
             sigma > 0,
             msg="sigma > 0",
         )
 
-    def icdf(value, mu, sigma):
-        res = pt.exp(mu - pt.sqrt(2 * sigma**2) * pt.erfcinv(2 * value))
-        res = check_icdf_value(res, value)
-        return check_icdf_parameters(
-            res,
-            sigma > 0,
-            msg="sigma > 0",
-        )
-
 
 Lognormal = LogNormal
 
@@ -2047,14 +2037,14 @@ def logcdf(value, alpha, beta):
             beta > 0,
             msg="beta > 0",
         )
-
+    
     def icdf(value, alpha, beta):
-        res = alpha + beta * pt.tan(np.pi * (value - 0.5))
+        res = alpha + beta * pt.tan(np.pi * (value-0.5))
         res = check_icdf_value(res, value)
         return check_parameters(
-            res,
-            beta > 0,
-            msg="beta > 0",
+                res,
+                beta > 0,
+                msg="beta > 0",
         )
 
 
@@ -3368,14 +3358,15 @@ def logp(value, mu, s):
 
     def logcdf(value, mu, s):
         res = -pt.log1pexp(-(value - mu) / s)
+        
         return check_parameters(
             res,
             s > 0,
             msg="s > 0",
         )
-
+    
     def icdf(value, mu, s):
-        res = mu + s * pt.log(value / (1 - value))
+        res = mu + s * pt.log(value/(1 - value))
         res = check_icdf_value(res, value)
         return check_parameters(
             res,

tests/distributions/test_continuous.py

@@ -502,16 +502,6 @@ def test_lognormal(self):
             {"mu": R, "sigma": Rplusbig},
             lambda value, mu, sigma: st.lognorm.logcdf(value, sigma, 0, np.exp(mu)),
         )
-        check_icdf(
-            pm.LogNormal,
-            {"mu": R, "tau": Rplusbig},
-            lambda q, mu, tau: st.lognorm.ppf(q, tau**-0.5, 0, np.exp(mu)),
-        )
-        check_icdf(
-            pm.LogNormal,
-            {"mu": R, "sigma": Rplusbig},
-            lambda q, mu, sigma: st.lognorm.ppf(q, sigma, 0, np.exp(mu)),
-        )
 
     def test_studentt_logp(self):
         check_logp(