Tests pass. Need to add a test for approach 2. Approach 1 might still…

… be wrong. Need to check using hand calcs.

Refs idaholab#101

python/mastodonutils/FTA.py

@@ -377,6 +377,14 @@ class Quantification(object):
     Calculates the minimal cut set probabilities and system level probability
     by propagating basic event probabilities through the fault tree.
 
+    Two approaches, 1 and 2, are used for top event risk calculation, 1 being
+    convolving basic event fragilities with hazard first and propagating risks
+    through the fault tree. In approach 2, the fragilities are propagated first
+    using the Min-Max method and the top event fragility is convolved with the
+    hazard to calculate risk.
+        - Risk calculated using approach 1 is provided by toprisk_1
+        - Risk calculated using approach 2 is provided by toprisk_2
+
     Inputs (9): (1,2,3,4,5,6 are for Fragility inputs). (1,2,3,7,8,9 are for Risk inputs)
     (0) name[str]: A string identifier for the instance of this class.
 

python/mastodonutils/test/test_quantification.py

@@ -114,11 +114,11 @@ def assertRisk(self, fta):
         Helper to make sure the FTA top event risk is correct.
         """
         # upper bound
-        self.assertEqual(fta.toprisk[0], 0.000704853860316601)
+        self.assertEqual(fta.toprisk_1[0], 0.000704853860316601)
         # rare event
-        self.assertEqual(fta.toprisk[1], 0.0007050000000000001)
+        self.assertEqual(fta.toprisk_1[1], 0.0007050000000000001)
         # min-max
-        self.assertEqual(fta.toprisk[2], 0.0006940240000000001)
+        self.assertEqual(fta.toprisk_1[2], 0.0006940240000000001)
 
     def assertIMratio(self, imratio):
         """