用C++编写的比较dft算法，有待优化成为fft算法，请提意见-C dft index prepared by the comparison algorithm, as fft pending optimization algorithm, please comment

快速傅立叶变换（FFT）算法实现 将DFT算法与FFT算法计算时间进行比较，分析二者的效率和精确差异。-Fast Fourier Transform (FFT) algorithm to DFT algorithm and FFT algorithm for computing time to carry out comparative analysis between the two differences in the efficiency and precision.

离散傅里叶变换对于FDTD计算程序很有用- an algorithm resistant to print/scan process is proposed , which is based on block discrete fourier transform