# 6.00 Problem Set 12 # # Name: # Collaborators: # Time: import numpy import random import pylab class NoChildException(Exception): """ NoChildException is raised by the reproduce() method in the SimpleVirus and ResistantVirus classes to indicate that a virus particle does not reproduce. You can use NoChildException as is, you do not need to modify/add any code. """ # # PROBLEM 1 # class SimpleVirus(object): """ Representation of a simple virus (does not model drug effects/resistance). """ def __init__(self, maxBirthProb, clearProb): """ Initialize a SimpleVirus instance, saves all parameters as attributes of the instance. maxBirthProb: Maximum reproduction probability (a float between 0-1) clearProb: Maximum clearance probability (a float between 0-1). """ # TODO def doesClear(self): """ Stochastically determines whether this virus is cleared from the patient's body at a time step. returns: Using a random number generator (random.random()), this method returns True with probability self.clearProb and otherwise returns False. """ # TODO def reproduce(self, popDensity): """ Stochastically determines whether this virus particle reproduces at a time step. Called by the update() method in the SimplePatient and Patient classes. The virus particle reproduces with probability self.maxBirthProb * (1 - popDensity). If this virus particle reproduces, then reproduce() creates and returns the instance of the offspring SimpleVirus (which has the same maxBirthProb and clearProb values as its parent). popDensity: the population density (a float), defined as the current virus population divided by the maximum population. returns: a new instance of the SimpleVirus class representing the offspring of this virus particle. The child should have the same maxBirthProb and clearProb values as this virus. Raises a NoChildException if this virus particle does not reproduce. """ # TODO class SimplePatient(object): """ Representation of a simplified patient. The patient does not take any drugs and his/her virus populations have no drug resistance. """ def __init__(self, viruses, maxPop): """ Initialization function, saves the viruses and maxPop parameters as attributes. viruses: the list representing the virus population (a list of SimpleVirus instances) maxPop: the maximum virus population for this patient (an integer) """ # TODO def getTotalPop(self): """ Gets the current total virus population. returns: The total virus population (an integer) """ # TODO def update(self): """ Update the state of the virus population in this patient for a single time step. update() should execute the following steps in this order: - Determine whether each virus particle survives and updates the list of virus particles accordingly. - The current population density is calculated. This population density value is used until the next call to update() - Determine whether each virus particle should reproduce and add offspring virus particles to the list of viruses in this patient. returns: the total virus population at the end of the update (an integer) """ # TODO # # PROBLEM 2 # def problem2(): """ Run the simulation and plot the graph for problem 2 (no drugs are used, viruses do not have any drug resistance). Instantiates a patient, runs a simulation for 300 timesteps, and plots the total virus population as a function of time. """ # TODO # # PROBLEM 3 # class ResistantVirus(SimpleVirus): """ Representation of a virus which can have drug resistance. """ def __init__(self, maxBirthProb, clearProb, resistances, mutProb): """ Initialize a ResistantVirus instance, saves all parameters as attributes of the instance. maxBirthProb: Maximum reproduction probability (a float between 0-1) clearProb: Maximum clearance probability (a float between 0-1). resistances: A dictionary of drug names (strings) mapping to the state of this virus particle's resistance (either True or False) to each drug. e.g. {'guttagonol':False, 'grimpex',False}, means that this virus particle is resistant to neither guttagonol nor grimpex. mutProb: Mutation probability for this virus particle (a float). This is the probability of the offspring acquiring or losing resistance to a drug. """ # TODO def getResistance(self, drug): """ Get the state of this virus particle's resistance to a drug. This method is called by getResistPop() in Patient to determine how many virus particles have resistance to a drug. drug: the drug (a string). returns: True if this virus instance is resistant to the drug, False otherwise. """ # TODO def reproduce(self, popDensity, activeDrugs): """ Stochastically determines whether this virus particle reproduces at a time step. Called by the update() method in the Patient class. If the virus particle is not resistant to any drug in activeDrugs, then it does not reproduce. Otherwise, the virus particle reproduces with probability: self.maxBirthProb * (1 - popDensity). If this virus particle reproduces, then reproduce() creates and returns the instance of the offspring ResistantVirus (which has the same maxBirthProb and clearProb values as its parent). For each drug resistance trait of the virus (i.e. each key of self.resistances), the offspring has probability 1-mutProb of inheriting that resistance trait from the parent, and probability mutProb of switching that resistance trait in the offspring. For example, if a virus particle is resistant to guttagonol but not grimpex, and `self.mutProb` is 0.1, then there is a 10% chance that that the offspring will lose resistance to guttagonol and a 90% chance that the offspring will be resistant to guttagonol. There is also a 10% chance that the offspring will gain resistance to grimpex and a 90% chance that the offspring will not be resistant to grimpex. popDensity: the population density (a float), defined as the current virus population divided by the maximum population activeDrugs: a list of the drug names acting on this virus particle (a list of strings). returns: a new instance of the ResistantVirus class representing the offspring of this virus particle. The child should have the same maxBirthProb and clearProb values as this virus. Raises a NoChildException if this virus particle does not reproduce. """ # TODO class Patient(SimplePatient): """ Representation of a patient. The patient is able to take drugs and his/her virus population can acquire resistance to the drugs he/she takes. """ def __init__(self, viruses, maxPop): """ Initialization function, saves the viruses and maxPop parameters as attributes. Also initializes the list of drugs being administered (which should initially include no drugs). viruses: the list representing the virus population (a list of SimpleVirus instances) maxPop: the maximum virus population for this patient (an integer) """ # TODO def addPrescription(self, newDrug): """ Administer a drug to this patient. After a prescription is added, the drug acts on the virus population for all subsequent time steps. If the newDrug is already prescribed to this patient, the method has no effect. newDrug: The name of the drug to administer to the patient (a string). postcondition: list of drugs being administered to a patient is updated """ # TODO def getPrescriptions(self): """ Returns the drugs that are being administered to this patient. returns: The list of drug names (strings) being administered to this patient. """ # TODO def getResistPop(self, drugResist): """ Get the population of virus particles resistant to the drugs listed in drugResist. drugResist: Which drug resistances to include in the population (a list of strings - e.g. ['guttagonol'] or ['guttagonol', 'grimpex']) returns: the population of viruses (an integer) with resistances to all drugs in the drugResist list. """ # TODO def update(self): """ Update the state of the virus population in this patient for a single time step. update() should execute these actions in order: - Determine whether each virus particle survives and update the list of virus particles accordingly - The current population density is calculated. This population density value is used until the next call to update(). - Determine whether each virus particle should reproduce and add offspring virus particles to the list of viruses in this patient. The listof drugs being administered should be accounted for in the determination of whether each virus particle reproduces. returns: the total virus population at the end of the update (an integer) """ # TODO # # PROBLEM 4 # def problem4(): """ Runs simulations and plots graphs for problem 4. Instantiates a patient, runs a simulation for 150 timesteps, adds guttagonol, and runs the simulation for an additional 150 timesteps. total virus population vs. time and guttagonol-resistant virus population vs. time are plotted """ # TODO # # PROBLEM 5 # def problem5(): """ Runs simulations and make histograms for problem 5. Runs multiple simulations to show the relationship between delayed treatment and patient outcome. Histograms of final total virus populations are displayed for delays of 300, 150, 75, 0 timesteps (followed by an additional 150 timesteps of simulation). """ # TODO # # PROBLEM 6 # def problem6(): """ Runs simulations and make histograms for problem 6. Runs multiple simulations to show the relationship between administration of multiple drugs and patient outcome. Histograms of final total virus populations are displayed for lag times of 150, 75, 0 timesteps between adding drugs (followed by an additional 150 timesteps of simulation). """ # TODO # # PROBLEM 7 # def problem7(): """ Run simulations and plot graphs examining the relationship between administration of multiple drugs and patient outcome. Plots of total and drug-resistant viruses vs. time are made for a simulation with a 300 time step delay between administering the 2 drugs and a simulations for which drugs are administered simultaneously. """ # TODO