Population_Growth_Modeler_CLR.py

#Cory Leigh Rahman
#GEOG469: Python with Dr. Bortolot
#Python 2.7.8
#This program estimates population over a specified number of years,
#then gives you the minimum and maximum ending ending populations over
#a specified number of iterations
#
#The formula used is as follows:
#starting population + (reproduction rate * starting population) + (death rate * starting population) - number hunted

import random

print "********************************"
print "Cory's Population Growth Modeler"
print "********************************"

def about_program():
    print
    print "This program estimates population over a specified number of years,"
    print "then gives you the minimum and maximum ending ending populations over"
    print "a specified number of iterations"
    print
    print "The formula used is as follows:"
    print "starting population + (reproduction rate * starting population) +"
    print "(death rate * starting population) - number hunted"
    print
    print "Code written by Cory Rahman"
    print "Dr. Bortolot's Python class"
    print "James Madison University"
    print
    startover()

def input_values():
    print
    print "***Using Input Values***"
    print
    
    min_val=1000000000000
    max_val=-1000000000000


    
    popn2=raw_input("Starting Population?: ")
    popn2_int=int(popn2)

    num_years=raw_input("Estimate the population after how many years?: ")
    num_years_int=int(num_years)
    num_years_int_correct=num_years_int+1
    
    num_iterations=raw_input("How many iterations would you like to run?: ")
    num_iterations_int=int(num_iterations)
    num_iterations_int_correct=num_iterations_int+1

    print
    print "Random variable extents:"
    print
    
    r1=raw_input("Minimum reproduction rate?: ")
    r1_float=float(r1)

    r2=raw_input("Maximum reproduction rate?: ")
    r2_float=float(r2)
    
    d1=raw_input("Minimum death rate?: ")
    d1_float=float(d1)

    d2=raw_input("Maximum death rate?: ")
    d2_float=float(d2)
    
    h1=raw_input("Minimum hunted per year?: ")
    h1_float=float(h1)
    
    h2=raw_input("Maximum hunted per year?: ")
    h2_float=float(h2)

    event_chance=raw_input("Percent chance of an event occuring that changes population?: ")
    event_chance_int=int(event_chance)

    popchange=raw_input("What number shall we multiply the population by for this event?: ")
    popchange_float=float(popchange)

    event_counter=0
    
    for iterations in range (0,num_iterations_int_correct):
        popn=popn2_int
        val=0
    
        for year in range (0,num_years_int_correct):
            r=random.uniform(r1_float,r2_float)
            d=random.uniform(d1_float,d2_float)
            h=random.uniform(h1_float,h2_float)
            event=random.randint(event_chance_int,101)
            popl=popn
            popn=popl+r*popl-d*popl-h
            if popn<0:
                popn=0
            if year==20:
                val=popn
            if event==100:
                popn=popn*popchange_float
                event_counter+=1
        if val<min_val:
            min_val=val
        if val>max_val:
            max_val=val
    
    min_val_int=int(min_val)
    max_val_int=int(max_val)
    average_val=int((min_val+max_val)/2)
    print
    print "Results:"
    print "Out of",num_iterations_int,"iterations:"
    print "Number of events occured: ", event_counter
    print "Minimum value:",min_val_int
    print "Maximum value:",max_val_int
    print "Average:",average_val

    startover()
    

def default_values():
    print
    print "***Using Default Values***"
    print

    min_val=1000000000000
    max_val=-1000000000000
    event_counter=0

    for iterations in range (0,101):
        popn=3000
        val=0
    
        for year in range (0,21):
            r=random.uniform(.9,1.4)
            d=random.uniform(.9,1.1)
            h=random.uniform(100,200)
            event=random.randint(0,101)
            popl=popn
            popn=popl+r*popl-d*popl-h
            if popn<0:
                popn=0
            if year==20:
                val=popn
            if event==100:
                popn=popn*.9
                event_counter+=1
        if val<min_val:
            min_val=val
        if val>max_val:
            max_val=val
    
    min_val_int=int(min_val)
    max_val_int=int(max_val)
    average_val=int((min_val+max_val)/2)

    print "Results:"
    print "Out of 100 iterations:"
    print "Number of events occured: ", event_counter
    print "Minimum value:",min_val_int
    print "Maximum value:",max_val_int
    print "Average:", average_val

    startover()


def end():
    print
    print "Thanks for using Cory's Population Growth Model! Goodbye."

def startover():
    
    print
    startoverx=raw_input("Start Over? Yes(1) or No, End Program(2): ")

    startover_int=float(startoverx)

    if startover_int==1:
        print
        print "**Starting Over**"
        print
        start()
    elif startover_int==2:
        end()
    else:
        print
        print "*Invalid Input*"

        startover()


def start():
    event_counter=0
    print
    q1=raw_input("----------MENU----------"
                 '\n' "(1) Use Default Values"
                 '\n' "(2) Enter Your Own Values"
                 '\n' "(3) About"
                 '\n' "(4) End Program"
                 '\n' "Please select from the above:")

    q1_int=int(q1)
    if q1_int==1:
        default_values()
    elif q1_int==2:
        input_values()
    elif q1_int==3:
        about_program()
    elif q1_int==4:
        end()
    else:
        print
        print "*Invalid Input*"
        start()

start()