Rpeak_detection

《navigaiton signal processing for gnss》一书的源代码，对于gps开发非常实用(《Navigaiton signal processing for gnss》 books source code, very useful for the development gps)

The bit modifying instructions on SH-2A are only capable of working with a 3-bit immediate, which signifies the shift position for the bit being worked on.

Matlab tour for fluid mechanics

matlab中fspecial函数的C++实现(Matlab implementation of fspecial function in C++ )

说明：  c++ 中使用 matlab 简单画图 开发为环境为vs2010(use matlab in c++)

此代码实现matlab画图时添加两个纵向游标（可以拖动）来实现同一横坐标幅度的对比，里面有测试程序。(This code implements the MATLAB drawing added two vertical cursors to implement rate comparison)

适合任何信号的模糊函数的画法。运行时要明白要要输入的那几个字母的实际含义。首先要将你的信号进行离散化，Signal elements（u_basic）就是你的信号矢量。Frequency coding in units of 1/tb你信号的采样频率，Over sampling ratio表示要满足采样定理（采样频率大于两边以上信号最高频率），其他的直接翻译过来就可以了 (Ambiguity function for any signal of painting. Run-time to understand that to enter a few letters to the actual meaning. First, you want to discrete signals, Signal elements (u_basic) is your signal vector. Frequency coding in units of 1/tb your signal sampling frequency, Over sampling ratio that should satisfy the sampling theorem (sampling frequency is greater than the highest frequency signal on both sides of the above), the other can be directly translated to the)

介绍了常见的时频分析方法，包括短时傅里叶变换，Wigner-Ville分布以及小波变换等，结合MATLAB，引导读者如何运用其来进行时频分析(Describes the common time-frequency analysis methods, including short time Fourier transform, Wigner-Ville distribution and wavelet transform, combined with MATLAB, to guide the reader how to use it to carry out time-frequency analysis)

image encryption and decryption using mckba algorithm

substitution cipher is the method of encoding in which unit of plain text are replaced by cipher text. Monoalphabetic cipher uses a fixed message over entire message.A monoalphabetic cipher uses fixed substitution over the entire message.The monoalphabetic substitution takes a letter of an alphabet and substitutes it with another letter, this way a ciphertext is generated. The way of converting is fixed. A character of the plaintext will be replaced by the same ciphertext character, during the entire ciphertext. There is no additional key. The only way of security is to keep the substitution-table secret. A popular example for the monoalphabetic substitution is the caesar cipher.