常用数值算法的C++源码，包括三次样条插值、二重积分计算、常微分初值问题数值解、Newton迭代法、列主元高斯消去法、逐次超松弛迭代法。-Numerical algorithm used in C++ source code, including the cubic spline interpolation, double integral, the ordinary differential initial value problem numerical solution, Newton it

使用高斯、复合梯形、复合辛普生求解二重积分（矩形求积区域和三角型求积区域）的数值计算方法，使用C语言。-Use Gaussian composite trapezoidal composite Simpson solving double integrals (Rectangular Quadrature region and the triangular the Quadrature area), numerical methods, the use of the C language.

计算二重的积分，用高斯方法，节点取n=3-Calculate two weight points, using the Gauss method, node taken n = 3