added conditional probability generator

mathgenerator/funcs/__init__.py

@@ -105,3 +105,4 @@ from .power_of_powers import *
 from .quotient_of_power_same_base import *
 from .quotient_of_power_same_power import *
 from .complex_quadratic import *
+from .conitionalProbability import *

mathgenerator/funcs/conitionalProbability.py

@@ -0,0 +1,25 @@
+from .__init__ import *
+
+def conditionalProbFunc():
+    P_disease= round(2.*random.random(), 2)
+    true_positive= round(random.random()+float(random.randint(90,99)), 2)
+    true_negative= round(random.random()+float(random.randint(90,99)), 2)
+
+    def BayesFormula(P_disease, true_positive, true_negative):
+        P_notDisease= 100.-P_disease
+        false_positive= 100.-true_negative
+        false_negative= 100.-false_positive
+        P_plus= (P_disease)*(true_positive)+(P_notDisease)*(false_positive)
+        P_disease_plus=( (true_positive)*(100*P_disease) )/P_plus
+
+        return P_disease_plus
+
+    problem= "Someone tested positive for a nasty disease which only {0:.2f}% of population have. " \
+    "Test sensitivity (true positive) is equal to SN= {1:.2f}% whereas test specificity (true negative) SP= {2:.2f}%. " \
+    "What is the probability that this guy really has that disease?".format(P_disease, true_positive, true_negative )
+    
+    answer=str(round(BayesFormula(P_disease, true_positive, true_negative), 2))+"%"
+
+    return problem, answer
+
+conditionalProb= Generator("Conditional Probability", 101, "P(A|+)=", "c", conditionalProbFunc)