Hi, I need some help in completing the second part of my assignment, guitar string.py. I completed the first part, ring buffer, and need to use it to complete the second part, any help?

Here is the ring_buffer.py

""" ring_buffer.py

Models a ring buffer. """

import stdarray import stdio import sys

def create(capacity): buff = stdarray.create1D(capacity, None) size = 0 first = 0 last = 0 rb = [buff, size, first, last] return rb

def capacity(rb): """ Return the capacity of the ring buffer. """ capacity = len(rb[0]) return capacity

def size(rb): """ Return the number of items currently in the buffer rb. """ items = rb[1] return items

def is_empty(rb): """ Return True if the buffer rb is empty and False otherwise. """ if (size(rb) == 0): return True else: return False

def is_full(rb): """ Return True if the buffer rb is full and False otherwise. """ if (size(rb) == capacity(rb)): return True else: return False

def enqueue(rb, x): """ Add item x to the end of the buffer rb. """ rb[0][rb[3]] = x if (rb[3] + 1) == capacity(rb): rb[3] = 0 else: rb[3] += 1 rb[1] += 1

def dequeue(rb): """ Delete and return item from the front of the buffer rb. """ v = None v = rb[0][rb[2]] if (rb[2] + 1) == capacity(rb): rb[2] = 0 else: rb[2] += 1 rb[1] -= 1 return v

def peek(rb): """ Return (but do not delete) item from the front of the buffer rb. """ peek_rb = rb[0][rb[2]] return peek_rb

def _main(): """ Test client [DO NOT EDIT]. """

N = int(sys.argv[1]) rb = create(N) for i in range(1, N + 1): enqueue(rb, i) t = dequeue(rb) enqueue(rb, t) stdio.writef('Size after wrap-around is %d ', size(rb)) while size(rb) >= 2: x = dequeue(rb) y = dequeue(rb) enqueue(rb, x + y) stdio.writeln(peek(rb))

if __name__ == '__main__': _main()

----------------------------------------------------------------------------------------------------------------------------------------

And here is guitar_string.py HELP HERE

""" guitar_string.py

Models a guitar string. """

import math import random import ring_buffer import stdarray import stdio import sys

# Sampling rate. SPS = 44100

def create(frequency): """ Create and return a guitar string of the given frequency, using a sampling rate given by SPS. A guitar string is represented as a ring buffer of of capacity N (SPS divided by frequency, rounded up to the nearest integer), with all values initialized to 0.0. """

def create_from_samples(init): """ Create and return a guitar string whose size and initial values are given by the list init. """

def pluck(string): """ Pluck the given guitar string by replacing the buffer with white noise. """

def tic(string): """ Advance the simulation one time step on the given guitar string by applying the Karplus-Strong update. """

...

def sample(string): """ Return the current sample from the given guitar string. """

...

def _main(): """ Test client [DO NOT EDIT]. """

N = int(sys.argv[1]) samples = [.2, .4, .5, .3, -.2, .4, .3, .0, -.1, -.3] test_string = create_from_samples(samples) for t in range(N): stdio.writef('%6d %8.4f ', t, sample(test_string)) tic(test_string)

if __name__ == '__main__': _main()

GUIDELINES HERE

create_from_samples(init) = 1. (Create a ring buffer whose capacity is same as the size of the given list init), 2. (Populate the ring buffer with values from init), 3. Return the ring buffer

pluck(string) = Replace each value (dequeue followed by enqueue) in the given ring buffer with a random number from the interval [0.5, 0.5]

tic(string) = Dequeue a value a in the given ring buffer and peek at the next value b Enqueue the value 0.996 * 0.5 * (a + b) into the ring buffer

sample(string) = Peek and return a value from the given ring buffer

Output for guitar_string.py should be like this

$ python guitar_string .py 25 0 0.2000 1 0.4000 2 0.5000 3 0.3000 4 -0.2000 5 0.4000 6 0.3000 7 0.0000 8 -0.1000 9 -0.3000 10 0.2988 11 0.4482 12 0.3984 13 0.0498 14 0.0996 15 0.3486 16 0.1494 17 -0.0498 18 -0.1992 19 -0.0006 20 0.3720 21 0.4216 22 0.2232 23 0.0744 24 0.2232