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Generate_SystemMatrix
本程序在matlab中运行。
Generate_SystemMatrix是一个计算OSEM，MLEM迭代图像算法中系统矩阵的函数，其用法Generate_SystemMatrix（pixel），为所要重建图像的大小，一般为64,128,256，pixel也大运算越慢。
里面的diedai-test文件是一个简单的MLEM重建算法，其中要加载SystemMatrix矩阵就是Generate_SystemMatrix(128)的结果，注意如果要运行diedai-test，生成的系统矩阵名要保存为SystemMatrix，否则出错。
testsino是一个正弦图实例，就是MLEM算法中的投影矩阵，机算是数据。(This program is run in matlab. The Generate_SystemMatrix is a calculation of the OSEM, a function of the system matrix MLEM iterative image algorithm, its use Generate_SystemMatrix (pixel) to rebuild the image size, usually 64,128,256, pixel also large computing slower. Inside diedai-test file is a simple MLEM reconstruction algorithm, which load SystemMatrix matrix is the result of Generate_SystemMatrix (128), pay attention to if you want to to run diedai-test, the generated system matrix is saved as SystemMatrix, otherwise an error. testsino instance of a sinogram projection matrix MLEM algorithm, machine be regarded as data.)
- 2020-12-08 14:39:20下载
- 积分：1
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GroupDelay
说明： Group delay calculation
- 2020-06-21 19:40:01下载
- 积分：1
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thin_plate
薄板样条，一种很好的拟合曲线的方法。是最近比较常用的拟合方法。(thin plate spline is so nice fitting method.
Features:
(1) support arbitrary control points
(2) allow regularization
(3) estimate the warp parameters from corresponding pairs
)
- 2009-03-13 15:32:13下载
- 积分：1
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zyp
计算各种气象物理量，包括散度、涡度、螺旋度、垂直速度、水汽通量、比湿、假相当位温、k指数等的grads 程序，(Calculate various meteorological physical quantity, including divergence, vorticity, helicity, vertical velocity, water vapor flux, specific humidity, pseudo-equivalent temperature, k index grads program,)
- 2021-05-07 18:01:36下载
- 积分：1
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kfilter
说明： 用于石油地震资料数字处理，包括 地震偏移（二维或三维）、滤波程序、重采样、具有很广的应用前景，还可以移植到其他的工程领域。(oil for digital processing seismic data, including seismic migration (2D or 3D), filtering procedures, re-sampling, have a very broad application prospects, but also can be transferred to other engineering fields.)
- 2006-03-06 11:20:40下载
- 积分：1
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Euler_DG_Quadrilateral_2D
自己写了一个二维Euler方程的间断有限元程序
上次发了一个三角形单元的程序 因为不是曲边单元 所以在圆柱后面容易形成涡
现在把程序改为曲边四边形单元了 没有涡出现
单元是8节点四边形单元 节点编号顺序是 1 5 2 6 3 7 4 8 也就是四个角点依次
是1 2 3 4 然后是边的中点编号 5 6 7 8.
时间推进采用 Runge-Kutta 方法
数值通量采用全局Lax-Friedrichs通量
仍然不能捕捉激波 因为没有做重构或者加人工粘性 等这个做出来了 再发一次。
程序没有进行优化 比如说内存的消耗没有优化 比如直边单元的边界积分仍然采
用了曲边的积分方法 增加了计算量 比如面积分、线积分都是采用的是Gauss-
Legendre-Lobatto积分 积分精度会比一般的Gauss-Legendre积分精度低一阶 等
等问题。 二维的 纯属交流性质 就没有考虑这些问题 ^_^
如果物面全部是直边 那么只要改变一个参数N 就可以获得不同的计算精度 且具
有谱精度 因为单元的节点是Gauss-Legendre-Lobatto积分点。 其实就是谱元法
（物面是曲边的情况我不清楚是不是也可以通过提高基函数的阶数 也就是增加N
来提高计算精度）(Wrote a two-dimensional Euler equations with discontinuous finite element program
Last made a triangular element of the program, not curved edge unit is so easy to form a vortex in the cylinder behind the
Program to curved edge quadrilateral element vortices appear
Unit is the order of 8-node quadrilateral element node number is 15,263,748 which is the four corners of the points in turn
Is 1234 and then the side of the midpoint of the number 5678.
Time promote the use of Runge-Kutta method
Numerical flux of the overall situation of Lax-Friedrichs, flux
Still can not capture the shock wave did not do the reconstruction or artificial viscosity do it Zaifayici.
The program is not optimized for example, memory consumption is not optimized such as straight-edge boundary integral of the unit is still mining
Integral method to increase the amount of computation such as surface integral with a curved edge, the line integral using the Gauss-
The Legendr)
- 2021-01-29 12:58:40下载
- 积分：1
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第一章作业
分别以单精度和双精度数据类型用以下近似算法分别计算π的近似值，要求结果具有4位有效数字(calculate pi with single-precision and double-precision respectively)
- 2021-03-17 18:19:21下载
- 积分：1
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FRIC
abaqus子程序fric摩擦材料clough-duncan模型，二三维通用，已经验证(abaqus subroutine frictional material fric)
- 2020-12-18 16:59:11下载
- 积分：1
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Interpolation-Methods
插值法：
（1）拉格朗日插值
（2）牛顿插值
（3）分段线性插值
（4）Hermite 插值
（5）样条插值(Interpolation method: (1) Lagrange Interpolation (2) Newton interpolation (3) piecewise linear interpolation (4) Hermite interpolation (5) spline interpolation)
- 2020-10-17 12:27:27下载
- 积分：1
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Calculator_
有加减乘除和括号运算功能的计算器，还可以算三角函数(calculator including plus，minus,mutiply,add)
- 2014-12-30 22:55:46下载
- 积分：1
