说明：   matlab绘制不同概率各种占空比的矩形随机信号的功率谱密度，本人亲自编写，代码精简效率高，且结果准确（网上流传的各种绘制矩形随机信号功率谱密度的matlab代码能画对的极少见...).
(matlab draw rectangle with different probabilities of various duty cycle of the power spectral density of random signals, I am personally prepared, the code streamlined efficient and accurate (spread of the Internet to draw rectangles of various random signal power spectral density matlab code to draw on the rare ...).)