如何创建具有变化幅度和相位的合成余弦波？

Question

I am trying to make a cosine wave on numpy that changes with amplitude and phase over time? How might I do that?

I have this so far, but the amplitude nor phase is changing over time:

east_sine = np.zeros((50,50))
sine = np.zeros((50))

for t in range(50):
    for x in range(50):
        sine[x] = np.sin(20*x*np.pi/100 - .1*t) 
        east_sine[t,:] = sine 

Answer 1

Please be more specific with your questions.

If you want to have time-dependent amplitude and phase, you need define the sine in the form:

sine = A(t) * sin(a*x - b(t)*t)

For example, where A(t) = t and b(t) = 0.1 t**2 :

x = np.linspace(0,50,1000)
t = np.linspace(0,10,1000)

sine =  t * np.sin(x - 0.1*np.square(t)*t)