Question

PYHTON

5.27 LAB: Predator-Prey Simulation In a predator-prey simulation, you compute the populations of predators and prey using the following equations prey(t +1) prey(t) x (1A- Bx pred(t) pred(t +1)-pred(t) x (1-C+ D x prey(t) Here, A is the rate at which prey birth exceeds natural death, B is the rate of predation, C is the rate at which predator deaths exceed births without food, and D represents predator increase in the presence of food. The units of time t are expressed in years. Write a program that prompts the user for the initial population sizes, these rates, and the number of years. Then print the populations for the given number of years after your simulation has completed. Hint: This can be accomplished in about 15 lines of code.

Answer 1

Code Screenshots:

# Read and store the # initial population # size of the preys. num_prey = int(input () ) # Read and store the # initial population # size of the predators. num pred = int (input () ) # Read and store the # values for A, B, C, # D, and t. A = float (input ( ) ) = float (input () ) C = float (input ( ) ) = float (input ( ) ) t = int (input ()) # Run the loop # to perform the # calculations, t times. for i in range (t): # Get the current population # sizes using the previous # population sizes. curr prey = num prey * (1 + A - B * num pred) curr_pred = num_pred * (1 - C + D * num_prey) # Update the # population sizes. num_prey = int(curr_prey) num pred = int(curr pred) # Print the final # population sizes. print (num prey, num pred)

Sample Input:

1000 20 0.1 0.01 0.01 0.00009 30

Sample Output:

| 23 18

Code to Copy:

# Read and store the

# initial population

# size of the preys.

num_prey = int(input())

# Read and store the

# initial population

# size of the predators.

num_pred = int(input())

# Read and store the

# values for A, B, C,

# D, and t.

A = float(input())

B = float(input())

C = float(input())

D = float(input())

t = int(input())

# Run the loop

# to perform the

# calculations, t times.

for i in range(t):

    # Get the current population

    # sizes using the previous

    # population sizes.

    curr_prey = num_prey * (1 + A - B * num_pred)

    curr_pred = num_pred * (1 - C + D * num_prey)

    

    # Update the

    # population sizes.

    num_prey = int(curr_prey)

    num_pred = int(curr_pred)

# Print the final

# population sizes.

print(num_prey, num_pred)