模拟连续独立信号。产生一段在[-1,+1]上均匀分布的独立随机信号，长度为0.5s。(1)绘制该段信号的波形；(2)求自相关函数；(3)计算其功率谱-Continuous independent analog signals. Produce a in [-1,+1] on the uniform distribution of independent random signals, a length of 0.5s. (1) Draw the waveform of the paragraph

能够准确计算圆周率，理论上可以计算无数位，代码执行效率高，计算小数点后1000位用时0.5s左右；带有运算计时功能。-Able to accurately calculate pi, countless bits can be calculated theoretically, code execution efficiency, calculated after the decimal point around 1000 with a time 0.5s with Operational t