Add epsilon for numerical stability.

climax/core/loss.py

@@ -86,7 +86,9 @@ class BernoulliGammaLoss(NaNLoss):
 
         # Gamma contribution
         loss += p_true * (torch.log(p_pred + self.epsilon) + (gshape - 1) *
-                          torch.log(y_true + self.epsilon) - (y_true / gscale)
-                          - gshape * torch.log(gscale) - torch.lgamma(gshape))
+                          torch.log(y_true + self.epsilon) -
+                          y_true / (gscale + self.epsilon) -
+                          gshape * torch.log(gscale + self.epsilon) -
+                          torch.lgamma(gshape + self.epsilon))
 
         return - self.reduce(loss)