用matlab如何实现fft变换

说明：  实现f-k变换，功能强大，各种滤波处理，地震波等都能用(wavelet transformF -k transform, powerful, a variety of filtering, seismic waves can be used)

能够实现二维S变换的MATLAB程序，与Stockwell的经典程序不同(the code which can implements the 2D S-transform)

针对转子系统非线性动力学图谱分析，绘制转子的轨迹图，相图，频谱图以及庞加莱图。(analysis about nonlinear dynamics of the rotor bearing system)

基于matlab小波变换的轴承故障外圈点蚀分析。(Based on wavelet transform matlab punctuate eclipse outer bearing failure analysis.)

说明：  介绍傅立叶变换的漫画，不是大量公式叙述或证明，简洁生动，易于理解。(The caricature that introduces Fourier transform, is not a lot of formula narration or proof, concise and vivid, easy to understand.)

傅立叶变换方法并利用数据高程模型计算重力异常(Calculating gravity anomaly based on the DEM)

说明：  提出了一种基于复解析小波变换的相位诊断齿轮故障的方法。复解析小波变换将Hilbert变换与小波分析紧密结合在一起,具有自适应分析能力。利用复解析小波变换得到齿轮振动信号的相位,其功率谱图上可提取调制边频带结构来识别故障模式。试验结果表明这种方法可有效应用于齿轮局部故障诊断中。(A new method using the phase based on complex analytical wavelet transform for fault diagnosis of gears was proposed. The phase of vibration signals of gears is got by complex analytical wavelet transform, which combines Hilbert transform with wavelet transform tightly and possesses adaptive analysis ability. By making spectrum analysis of the phase, the sideband structure in power spectrum can be protruded, and the fault pattern can be identified. Experimental results show that the proposed method is effective in local defect detection of gears.)

说明：  紧支撑小波基的构造。 以Daubechies小波滤波器系数为例，推导出小波函数及尺度函数，并画出其图像. void Convolution(double* pShortData, int nShort, double* pLongData, int nLong) int CalcScaleFunction(double* pOutData) int CalcWaveletFunction(double* pOutData) Convolution()不是通用的离散卷积代码，而是简单地实现了后面两个函数需要的离散卷积，它要求输入的前一个数组长度小于后一数组长度，而且卷积结果就直接覆盖存储在后一数组中。CalcScaleFunction()计算尺度函数，CalcWaveletFunction()计算小波函数。 (Compactly supported wavelet bases constructed. To Daubechies wavelet filter coefficients as an example, the derived wavelet function and scaling function, and draw their images. Void Convolution (double* pShortData, int nShort, double* pLongData, int nLong) int CalcScaleFunction (double* pOutData) int CalcWaveletFunction ( double* pOutData) Convolution () instead of generic discrete convolution code, but simply the realization of a function behind the need for two discrete convolution, which requires input before an array length is less than the array length of the latter, but the result of convolution directly covered by the latter is stored in the array. CalcScaleFunction () calculated scaling function, CalcWaveletFunction () calculation of wavelet function.)

一篇很好的小波变换英文入门资料，附有注释，对想了解小波变换的初学者十分有益。(A good wavelet transform introductory information in English, annotated, very useful for beginners want to learn wavelet transform.)

关于小波变换的一些常用函数，有关多尺度变换，希望可以帮助您(Wavelet commonly used functions, on multi-scale transformation, I hope to help you)