Update beta_geo.py

Correcting the expected alive probability theoretical formula
PabloRoque · Aug 10, 2023 · 882fffa · 882fffa
1 parent 601fca8
commit 882fffa
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/pymc_marketing/clv/models/beta_geo.py b/pymc_marketing/clv/models/beta_geo.py
@@ -294,13 +294,13 @@ def expected_probability_alive(
         derivation of the closed form solution is available in [2].
 
         .. math::
-            P\left\text{alive} \mid x, t_x, T, r, \alpha, a, b\right)
+            P\left( \text{alive} \mid x, t_x, T, r, \alpha, a, b \right)
             = 1 \Big/
                 \left\{
                     1 + \delta_{x>0} \frac{a}{b + x - 1}
                         \left(
-                            \frac{\alpha + T}{\alpha + t_x}^{r + x}
-                        \right)^{r x}
+                            \frac{\alpha + T}{\alpha + t_x}
+                        \right)^{r + x}
                 \right\}
         """
         T = np.asarray(T)