def update(self, k, current_state, next_state):
""" updates the discounted total cost and health utility
:param k: simulation time step
:param current_state: current health state
:param next_state: next health state
"""
# update cost
cost = (self.params.annualTotalCosts[current_state.value] +
self.params.annualTotalCosts[next_state.value])
# # update utility
# utility = 0.5 * (self.params.annualTotalUtility[current_state.value] +
# self.params.annualTotalUtility[next_state.value])
# add the cost of treatment
if current_state == P.HealthStates.ACTIVE_TB and next_state == P.HealthStates.ACTIVE_TB:
cost += 1 * self.params.annualTreatmentCost
elif current_state == P.HealthStates.ACTIVE_TB and next_state == P.HealthStates.CURED or P.HealthStates.INCOMPLETE:
cost += 0.5 * self.params.annualTreatmentCost
# update total discounted cost and utility (corrected for the half-cycle effect)
self.totalDiscountedCost += Econ.pv_single_payment(
payment=cost,
discount_rate=self.params.discountRate,
discount_period=k + 1)
def update(self, time, current_state, next_state):
""" updates the discounted total cost and health utility
:param time: simulation time
:param current_state: current health state
:param next_state: next health state
"""
# cost and utility (per unit of time) during the period since the last recording until now
cost = self.params.weeklyStateCosts[current_state.value]
single_cost = self.params.singleCosts[current_state.value]
# utility = self.params.weeklyStateUtilities[current_state.value]
# discounted cost and utility (continuously compounded)
discounted_cost = Econ.pv_continuous_payment(
payment=cost,
discount_rate=self.params.discountRate,
discount_period=(self.tLastRecorded, time))
# discounted_utility = Econ.pv_continuous_payment(payment=utility,
# discount_rate=self.params.discountRate,
# discount_period=(self.tLastRecorded, time))
# discounted cost (single payment)
discounted_cost += Econ.pv_single_payment(
payment=single_cost,
discount_rate=self.params.discountRate,
discount_period=time,
discount_continuously=True)
# update total discounted cost and utility
self.totalDiscountedCost += discounted_cost
# self.totalDiscountedUtility += discounted_utility
# update the time since last recording to the current time
self.tLastRecorded = time
def update(self, k, current_state, next_state):
""" updates the discounted total cost and health utility
:param k: simulation time step
:param current_state: current health state
:param next_state: next health state
"""
# update cost
cost = 0.5 * (self.params.annualStateCosts[current_state.value] +
self.params.annualStateCosts[next_state.value])
# update utility
# utility = 0.5 * (self.params.annualStateUtilities[current_state.value] +
# self.params.annualStateUtilities[next_state.value])
# add the cost of treatment
# if Chron's death will occur, add the cost for half-year of treatment
if next_state == P.HealthStates.DEATH:
cost += 0.5 * self.params.annualTreatmentCost
else:
cost += 1 * self.params.annualTreatmentCost
# update total discounted cost and utility (corrected for the half-cycle effect)
self.totalDiscountedCost += Econ.pv_single_payment(
payment=cost,
discount_rate=self.params.discountRate / 2,
discount_period=2 * k + 1)
import SimPy.EconEvalClasses as Econ
print('Present value of $10 collected in year 20 at discount rate 5%:')
print(
Econ.pv_single_payment(payment=10, discount_rate=0.05, discount_period=20))
print(
'\nPresent value of $10 collected in year 20 at discount rate 5% (discounted continuously):'
)
print('These 2 numbers should be almost the same:')
print(
Econ.pv_single_payment(payment=10,
discount_rate=0.05,
discount_period=20,
discount_continuously=True))
print(
Econ.pv_single_payment(payment=10,
discount_rate=0.05 / 100,
discount_period=20 * 100,
discount_continuously=False))
print(
'\nPresent value of a continuous payment of $10 over the period [10, 20] at discount rate 5%:'
)
print(
Econ.pv_continuous_payment(payment=10,
discount_rate=0.05,
discount_period=(10, 20)))
print(
'\nPresent value of a continuous payment of $10 over the period [10, 20] at discount rate 0%:'
)