Karplus Strong Algorithm, y[n] = ay[n-M] + x[n]

KarplusStrong.py

class KarplusStrong:
    def ks_loop(self, x, alpha, D):
        import numpy as np
        
        if D < 1:
            print('Duration D must be greater than 1')
            
        if x.ndim != 1:
            print('The array entered is of the wrong size')
            return None
            
        M = len(x)
        
        size_y = D*M
        
        y = np.zeros((size_y, 1))
        
        for i in range(M):
            y[i] = x[i]
            
        for index in range(M+1, size_y):
            y[index] = float(alpha*y[index - M])
            
        return y

Karplus Strong Algorithm, y[n] = ay[n-M] + x[n]#
x[n] --> Input Signal
M --> Delay
a --> a is the alpha, decay component.

Python CLI Commands

import numpy as np
x = np.random.randn(100)

from KarplusStrong import KarplusStrong
ks = KarplusStrong()
y = ks.ks_loop(x, 0.9, 10)

stem(np.arange(x.size),x,)
xlabel('Samples')
ylabel('x')
show
size(y)