仿真不同频率的组合信号通过滤波器后作FFT，得到滤波后信号的fft频谱及fft求模，并找出最大值及索引，非常实用。-The combination of simulation of different frequency signal through a filter made after FFT, the filtered signal the fft spectrum and fft modulo, and find out the maximum and the index is very

创建一个数组，确定数组的维数和元素的个数及数值大小，确定最大和最小索引值后，在数组中寻找到最小值和最大值，并显示出来-Create an array, to determine the dimensions of the array and the number of elements and numerical size, determine the index of maximum and minimum values, find the minimum and maximum values