signal.py 文件源码

def render(self, length=None, progress=False):
        """
        Render this signal into an numpy array of floats. Return the array.

        :param length:      The length to render, in seconds. Optional.
        :param progress:    Whether to show a progress bar for rendering
        """
        if progress and not progressbar:
            print('Install the progressbar module to see a progress bar for rendering')
            progress = False

        duration = self.duration if length is None else length * SAMPLE_RATE
        if duration == float('inf'):
            duration = 3*SAMPLE_RATE
        else:
            duration = int(duration)
        out = numpy.empty((duration, 1))

        pbar = progressbar.ProgressBar(widgets=['Rendering: ', progressbar.Percentage(), ' ', progressbar.Bar(), ' ', progressbar.ETA()], maxval=duration-1).start() if progress else None

        for i in range(duration):
            out[i] = self.amplitude(i)
            if pbar: pbar.update(i)
        if pbar: pbar.finish()
        return out