function [ue,un]=UPW_utux0(v,dt,t)

一个简单的双曲型偏微分方程：

ut + ux = 0

初始条件为：

u(x,0) = 1, x≤0

0, x＞0.

边界条件为：

u(-1,t)=1,u(1,t)=0.

本题要求：

使用迎风格式，选择 v=0.5, 计算并画出当dt=0.01和0.0025时，

方程在t=0.5，x在(-1,1)时的数值解和精确解

输入：

v--即a*dt/dx

dt--数值格式的时间步

t--要求解的时间

输出：

ue--在时间t时的1×N精确解矩阵

un--在时间t时的1×N数值解矩阵

输出图像：

精确解和数值解的图像-function [ue, un] = UPW_utux0 (v, dt, t)　 A simple hyperbolic partial differential equation:　ut+ ux = 0　 initial conditions:　u (x, 0) = 1, x ≤ 0　 0, x>　0　boundary conditions:　u (-1, t) = 1, u (1, t) = 0　of the questions asked:　using the upwind scheme, choose v = 0.5, calculated. and draw when dt = 0.01 and 0.0025,　equation t = 0.5, x numerical solution at (-1,1) and the exact solution when the　input:　v- that is, a* dt/dx　dt- time step numerical format　t- the time to be solved　Output:　ue- 1N exact solution at time t matrix　un- numerical solution 1N matrix　of the output image at time t is: Image　accuracy and numerical solutions of