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pythonsortingtrigonometryfakerheartrate

How to Sort Values According to Sine function?

I have generated random numbers in a certain range before sorting it:

A = []
for _ in range(10000):
    value = np.random.randint(60,100)
    A.append(value)
A = sorted(A)

But what I want to do is to obtain a list of A that is sorted like the sine graph (with peaks and valleys). So essentially the values should be sorted in a manner where it gradually rises and falls with valleys at 60 and peaks at 100.

I am trying to create very simple mock data simulating heart rate. I have thought about using sort using a custom key but I don't know where to start. I've also looked into Faker but I don't think I can achieve the generated data I wanted with it (correct me if I'm wrong!)

Totally up for different solutions for this problem. Thanks in advance!

Solution

  • One possibilitie is to generate random phases, meaning the arguments for the sin function. You have to decide first how many cycles you want (there are one valley and one peak for each cycle). If you want CY cycles then you have to generate numbers in the range (0, N * 2 * pi).

    Then sort the phases and last apply the sin function to the phases.

    import numpy as np
CY = 8
ph = np.random.rand(800) * CY * 2 * np.pi
ph.sort()
A = np.sin(ph)

# then you can plot the numbers, for example
from matplotlib import pyplot as plt
plt.plot(A)
plt.show()

    enter image description here

    the function call np.random.rand(800) generate 800 random numbers in the interval (0,1), so you have to multiply it to obtain the desired interval.

    If you use too many numbers, the result is undistinguishable from a sin function.

    Another posibilitie is start with a sin function and then add random numbers:

    N = 800; CY = 8; DEV = 0.3
sin = np.sin(np.linspace(0, CY*2*np.pi, N)) 
A = sin + np.random.rand(N) * DEV

    enter image description here

    Also you can try changing the sin function for another