fft

北京航空航天大学数值分析大作业第二题，有难度，这可是历年北航研究生转载最多的代码了(Beijing University of Aeronautics and Astronautics numerical analysis of large operating the second question, there is difficulty, this is the most over the years Beihang University Graduate reproduced the code)

有限元方法与C程序设计 介绍有限元方法原理和如何设计C程序，书后有相关代码。(Finite element method with the C programming)

C++实现的FFT，详细，简单，内含多个测试类(using C++ implements fft，including serials class)

用C语言编写的1D-FDTD程序，含一阶mur边界，附结果matlab画图程序(Using C language 1D-FDTD procedures, including an order Mur boundary, with results of MATLAB drawing program)

三维矢量有限元-矩量法电磁场分析程序。 EMAP5 is a full-wave electromagnetic field solver that combines the method of moments (MOM) with a vector finite element method (VFEM). It employs the finite element method (FEM) to analyze a dielectric volume, and employs the method of moments (MoM) to solve for currents on the surface of (or external to) this volume. The two methods are coupled through the fields on the dielectric surface.(Three-dimensional vector finite element- MoM electromagnetic field analysis program. EMAP5 is a full-wave electromagnetic field solver that combines the method of moments (MOM) with a vector finite element method (VFEM). It employs the finite element method (FEM) to analyze a dielectric volume, and employs the method of moments ( MoM) to solve for currents on the surface of (or external to) this volume. The two methods are coupled through the fields on the dielectric surface.)

利用PHOTOSHOP软件可以量测出左右像片各控制点的像素坐标，通过公式可以计算出其像点坐标。再根据给定的控制点的空间坐标，利用直线线性变换解法计算出11个DLT参数即l的系数值以及内方位元素然后解算出外方位元素。另外一种方式是用单像空间后方交会的公式计算出外方位元素。利用单像空间后方交会的来结算影像的外方位元素的基本思想是：以单幅影像为基础，从该影像所覆盖地面范围内若干控制点的已知地面坐标和相应点的像坐标量测值出发，根据共线条件方程，解求该影像在航空摄影时刻的外方位元素。首先建立单文档的程序，建立一个对话框类，在这个类中进行像素坐标、控制点坐标文件的打开与读取，然后利用DLT公式进行外方位元素的解算。 数据检核部分用前方交会算法来进行，首先根据ID找到左右片的像点的同名点，然后计算变换矩阵及系数，根据给定的内方位元素，利用公式解算出像点的控制点坐标，然后和给定的控制点坐标相比较即可进行精度评定。 (PHOTOSHOP software can be measured using a photo of the control points around the pixel coordinates can be calculated by the formula sit out the image point Standard. According to the given coordinates of control points, the use of straight-line method to calculate the linear transformation of 11 DLT parameters that the coefficient l Value and calculate the orientation elements of exterior orientation elements and solutions. Another way is to use a single formula as the calculation of space resection Orientation elements out. Use as space resection alone to settle the image exterior orientation is the basic idea: to single video As the basis of images from the ground covered by a number of control points within the known ground coordinates and image coordinates of corresponding points in the measured values , The realities of collinearity equation, find the image in the time of aerial photography exterior orientation elements. First, the process to establish a single document)

采用dsp产生lorenz信号，以用于混沌保密通信，程序在ccs下调试并通过(using dsp have lorenz signal to be used in chaotic secure communications, Under procedures in ccs through debugging and)

fft傅里叶快速变化程序，里面说的很清楚，很使用。(FFT Fourier rapid change program, which made it very clear, is to use. )

网上看到很多关于矩阵求逆运算的代码，都很杂很乱，我把代码重新真理了一边，可以直接编译运行(See a lot of online matrix inversion code, very complex mess, I put the code back to the side of truth, you can directly compile and run)

通过C语言，实现龙格库塔法，用四阶龙格库塔法求解一阶微分方程组。(Through the C language, the realization of Runge-Kutta method with fourth-order Runge-Kutta method for solving first-order differential equations.)