本文件包含三个小程序，分别为用fft实现功率谱估计、实现快速卷积和快速相关。对了解fft在c中的编程很有帮助-This document contains three procedures were used to achieve power spectrum estimation fft, fast convolution and fast correlation. Fft to know programming in c in the helpful

信号与系统分析 序列的卷积计算和相关函数的计算-Convolution calculation of the basic sequence of signals and systems analysis and calculation of the correlation function