BA_ScaleFree

利用FFT估计正弦信号的频率,要估计一个叠加了高斯白噪声的正弦信号 的频率 ，可以通过对x(n)做傅里叶变换，得到频谱图，找出幅度的最大值对应的频率值 ，进行多次变换，求出均方误差 。改变信噪比SNR，通过仿真可以得出随着信噪比增加，均方误差减小。(Sinusoidal signal using FFT frequency estimation, to estimate a Gaussian white noise superimposed on the frequency of sinusoidal signals, can be achieved by x (n) be the Fourier transform to get spectrum to identify the magnitude of the frequency value corresponding to the maximum , several transformations, find the mean square error. Change the signal to noise ratio SNR, the simulation can be drawn as the SNR increases, the mean square error decreases.)

室内无线定位技术，基于两次最小二乘法的matlab仿真程序(Indoor wireless positioning technology, based on the two least-squares method matlab simulation program)

本程序包括：DFT（离散傅里叶变换），FFT（快速傅里叶变换），IFFT（快速傅里叶逆变换），conv（卷积：圆周卷积、线性卷积），主要应用于信号处理，既可以对实序列做上述操作，也可以对复序列。(This process includes: DFT (Discrete Fourier Transform), FFT (fast Fourier transform), IFFT (inverse fast Fourier transform), conv (convolution: circular convolution, linear convolution), mainly used signal processing, either on the actual sequence to do the operation, can also be complex sequence.)

说明：  通过面积加权在abaqus程序中提取温度作用数据，计算极值(The temperature action data was extracted by area weighting in abAQUs program and the extreme value was calculated)

用多重网格方法求解泊松方程，偏微分方程求解(use multigrid method to solve poisson equation, pde solver)

实现了bch编码，基于有限域多项式除法,自己动手写的，大家可以看下(Based on division in galois field，relize the BCH code )

用C语言程序通过先随机选取K个对象作为初始的聚类中心。然后计算每个对象与各个种子聚类中心之间的距离，把每个对象分配给距离它最近的聚类中心。聚类中心以及分配给它们的对象就代表一个聚类。一旦全部对象都被分配了，每个聚类的聚类中心会根据聚类中现有的对象被重新计算。(C Programming Language by first randomly selected the K object as initial cluster centers. And then calculate the distance between each object and each seed cluster center, and assign each object to its nearest cluster center. Cluster centers, and the object assigned to them on behalf of a clustering. Once all the objects are assigned to each cluster cluster centers will be based on the existing object clustering is recalculated.)

相变UDF，包括质量传递和热量传递，能够进行气液相变的模拟(Phase transition UDF, including mass transfer and heat transfer, gas-liquid phase transition can be simulated)

说明：  这是高斯列主元消去法的完整程序，可以求解线性方程组(This is the Gaussian elimination method PCA out a complete program, you can solve the linear equations)

三次样条插值（简称Spline插值）是通过一系列形值点的一条光滑曲线，数学上通过求解三弯矩方程组得出曲线函数组的过程。本函数中采用第一类边界值(Cubic spline interpolation (referred Spline interpolation) through a series of key points of a smooth curve, mathematically by solving the three-moment equations derived curve function group process. This function uses the first boundary value)