signal.py 文件源码

def sweep(f1, f2, duration, fs, method='linear', window=None):
    """Generate frequency modulated sweep.

    :param f1: starting frequency in Hz
    :param f2: ending frequency in Hz
    :param duration: duration of the pulse in s
    :param fs: sampling rate in Hz
    :param method: type of sweep (``'linear'``, ``'quadratic'``, ``'logarithmic'``, ``'hyperbolic'``)
    :param window: window function to use (``None`` means rectangular window)

    For supported window functions, see documentation for :func:`scipy.signal.get_window`.

    >>> import arlpy
    >>> x1 = arlpy.signal.sweep(20000, 30000, duration=0.5, fs=250000)
    >>> x2 = arlpy.signal.cw(20000, 30000, duration=0.5, fs=250000, window='hamming')
    >>> x2 = arlpy.signal.cw(20000, 30000, duration=0.5, fs=250000, window=('kaiser', 4.0))
    """
    n = int(round(duration*fs))
    x = _sig.chirp(time(n, fs), f1, duration, f2, method)
    if window is not None:
        w = _sig.get_window(window, n)
        x *= w
    return x