Tsinghua-Matlab-Simulink

The NCT includes 4 External validity indices and 8 internal validity indices, and the sub-routine validity_Index.m is designed to use them. This tool is suitable for the research work such as the performance comparison of different indices on estimation of the number of clusters, algorithm design by improving part codes of this toolbox. i) External validity indices when true class labels are known: Rand index Adjusted Rand index Mirkin index Hubert index ii) Internal validity indices when true class labels are unknown: Silhouette Davies-Bouldin Calinski-Harabasz Krzanowski-Lai Hartigan weighted inter- to intra-cluster ratio Homogeneity Separation iii) Others Error rate (compared with true labels) System Evolution: it is used to estimate the number of clusters and give separable degrees between clusters.

用matlab编写的边界跟踪算法，用到了freeman链码和爬虫法，可以有效的跟踪单个物体边界，适合于初学者。( Prepared using matlab boundary tracking algorithm uses a freeman chain code and reptiles method can effectively track a single object borders, suitable for beginners.)

PCA神经网络及学习算法，简单的主分量分析(PCA neural networks and learning algorithms, a simple principal component analysis)

实现输入一串数字，然后matlab可以将数字对应的蜂鸣音播放出来（类似于电话的拨号）(Achieve input a string of numbers, then you can figure corresponding matlab beep play out (similar to dial-up phone))

使用Matlab写的EZW算法，里面有实例 (ezw algorithm, there are examples)

说明：  在MATLAB上用于产生WCDMA 仿真信号源的源程序(In MATLAB on WCDMA simulation used to produce the source signal source)

communication system

说明：  双音频按键识别 背景： 打电话拨号时，每次按键会发出不同的声音，这些声音实际上是由一些固定频率的正弦信号合成的。因为每个按键声音包含两个不同频率的正弦信号，因此也被称为“双音频”信号，简记为DTMF。这相当于是对不同键位用‘音频’进行了编码，如同计算机领域中用数字0和1对处理对象（包括键盘）进行编码。(Two-tone buttons identify Background: When you call dial, each key emits different sounds, which is actually made up of some fixed frequency sinusoidal signal synthesis. Because the sound of each key contains two sinusoidal signals of different frequencies, it is also known as &quot two-tone&quot signal, abbreviated as DTMF. This is equivalent to different keys using the ' audio' encoded, as the computer industry with the numbers 0 and 1 pair of processing object (including the keyboard) to be encoded.)

关于四旋翼飞行器的控制仿真，串级PID算法。有相关文献。(Control simulation of four rotor aircraft, cascade PID algorithm. There are relevant documents.)

选取试探函数求解双脊波导中截止频率和场分布(Selecting trial function to solve cut-off frequency and field distribution in double ridge waveguide)