时间轴构建器函数的优化

Question

我有一个带有频率F的平方信号，我对正方形启动的时间感兴趣。

def time_builder(f, t0=0, tf=300):
    """
    Function building the time line in ms between t0 and tf with a frequency f.
    f: Hz
    t0 and tf: ms
    """
    time = [t0]                         # /! time in ms
    i = 1
    while time[len(time)-1] < tf:
        if t0 + (i/f)*1000 < tf:
            time.append(t0 + (i/f)*1000)
        else:
            break
        i += 1
    return time

因此，此功能在T0和TF之间循环以创建一个列表，在该列表中，正方形开始的时间。我很确定这不是最好的方法，我想知道如何改进它。

谢谢。

Answer 1

如果我正确解释了这一点，您正在寻找波浪时间的列表，从T0开始，以TF结束。

def time_builder(f, t0=0, tf=300):
    """
    Function building the time line in ms between t0 and tf with a frequency f.
    f: Hz
    t0 and tf: ms
    """
    T = 1000 / f # period [ms]
    n = int( (tf - t0) / T + 0.5 ) # n integer number of wavefronts, +0.5 added for rounding consistency
    return [t0 + i*T for i in range(n)]

Answer 2

使用标准库python为此可能不是最好的方法...特别是考虑到您可能希望以后再做其他事情。

一种替代方法是使用numpy。这将使您进行以下

from numpy import np
from scipy import signal
t = np.linspace(0, 1, 500, endpoint=False)
s = signal.square(2 * np.pi * 5 * t)  # we create a square signal usign scipy
d = np.diff(s)  # obtaining the differences, this tell when there is a step. 
                # In this particular case, 2 means step up -2 step down.
starts = t[np.where(d == 2)]  # take the times array t filtered by which
                              # elements in the differences array d equal to 2