syntax积分（编程求ex在[0,1]的积分 ﾁ6ﾦ1提示:按积分的物理定义求 exp Syntax:）

本文目录

• 编程求ex在[0,1]的积分 ﾁ6ﾦ1提示:按积分的物理定义求 exp Syntax:
• 用Python求积分
• 定义了一个vc的结构体，总是报错
• 求一个matlab中离散一元函数积分的方法
• matlab 指数积分
• matlab中ployint的用法
• 求mathematica积分或者用matlab也行
• 怎么用Matlab编程计算积分！！！
• MATLAB计算两个变量的积分积分

编程求ex在[0,1]的积分 ﾁ6ﾦ1提示:按积分的物理定义求 exp Syntax:

积分是微积分学与数学分析里的一个核心概念。通常分为定积分和不定积分两种。直观地说，对于一个给定的正实值函数，在一个实数区间上的定积分可以理解为在坐标平面上，由曲线、直线以及轴围成的曲边梯形的面积值（一种确定的实数值）。

用Python求积分

科学计算应该要安装numpy，你可以去下Anaconda，全套自动打包好了的。

把代码改了一下：

# -*- coding: utf-8 -*-import mathimport sysimport timeimport numpy as npdef area():    x1=1            #起始区间    x2=4.5            #结束区间    dx=0.0001        #步长，步长越小越精确    y1=0    y2=0    y3=0            #结果    for x in np.arange(x1, x2, dx):        y1=y1+dx*x*x            #细小矩形取左边为高        y2=y2+ dx*(x+0.5*dx)*(x+0.5*dx)             #取中间        y3=y3+dx*(x+dx)*(x+dx)        print (y1, y2, y3)        start = time.clock()        area()end = time.clock()print (end-start)

定义了一个vc的结构体，总是报错

结构体定义格式：struct 结构类型名{数据类型1 成员名1;数据类型2 成员名2; // 成员数量不限 ： ：数据类型n 成员名n;};(注：要以分号;结尾）你定义的好像是个函数，还漏了一个返回值return *;

求一个matlab中离散一元函数积分的方法

用值积分，输入 doc quad 看看帮助和例子就知道了。 Syntaxq = quad(fun,a,b)q = quad(fun,a,b,tol)q = quad(fun,a,b,tol,trace) = quad(...)DescriptionQuadrature is a numerical method used to find the area under the graph of a function, that is, to compute a definite integral.q = quad(fun,a,b) tries to approximate the integral of function fun from a to b to within an error of 1e-6 using recursive adaptive Simpson quadrature. fun is a function handle. See Function Handles in the MATLAB Programming documentation for more information. Limits a and b must be finite. The function y = fun(x) should accept a vector argument x and return a vector result y, the integrand evaluated at each element of x.Parametrizing Functions, in the MATLAB Mathematics documentation, explains how to provide additional parameters to the function fun, if necessary.q = quad(fun,a,b,tol) uses an absolute error tolerance tol instead of the default which is 1.0e-6. Larger values of tol result in fewer function evaluations and faster computation, but less accurate results. In MATLAB version 5.3 and earlier, the quad function used a less reliable algorithm and a default relative tolerance of 1.0e-3.q = quad(fun,a,b,tol,trace) with non-zero trace shows the values of during the recursion. = quad(...) returns the number of function evaluations.The function quadl may be more efficient with high accuracies and smooth integrands.The list below contains information to help you determine which quadrature function in MATLAB to use: * The quad function may be most efficient for low accuracies with nonsmooth integrands. * The quadl function may be more efficient than quad at higher accuracies with smooth integrands. * The quadgk function may be most efficient for high accuracies and oscillatory integrands. It supports infinite intervals and can handle moderate singularities at the endpoints. It also supports contour integration along piecewise linear paths. * The quadv function vectorizes quad for an array-valued fun. * If the interval is infinite, [a,Inf), then for the integral of fun(x) to exist, fun(x) must decay as x approaches infinity, and quadgk requires it to decay rapidly. Special methods should be used for oscillatory functions on infinite intervals, but quadgk can be used if fun(x) decays fast enough. * The quadgk function will integrate functions that are singular at finite endpoints if the singularities are not too strong. For example, it will integrate functions that behave at an endpoint c like log|x-c| or |x-c|p for p 》= -1/2. If the function is singular at points inside (a,b), write the integral as a sum of integrals over subintervals with the singular points as endpoints, compute them with quadgk, and add the results.ExampleTo compute the integralwrite an M-file function myfun that computes the integrand:function y = myfun(x) y = 1./(x.^3-2*x-5);Then pass @myfun, a function handle to myfun, to quad, along with the limits of integration, 0 to 2:Q = quad(@myfun,0,2)Q = -0.4605Alternatively, you can pass the integrand to quad as an anonymous function handle F:F = @(x)1./(x.^3-2*x-5);Q = quad(F,0,2); Algorithmquad implements a low order method using an adaptive recursive Simpson’s rule.Diagnosticsquad may issue one of the following warnings:’Minimum step size reached’ indicates that the recursive interval subdivision has produced a subinterval whose length is on the order of roundoff error in the length of the original interval. A nonintegrable singularity is possible.’Maximum function count exceeded’ indicates that the integrand has been evaluated more than 10,000 times. A nonintegrable singularity is likely.’Infinite or Not-a-Number function value encountered’ indicates a floating point overflow or division by zero during the evaluation of the integrand in the interior of the interval.

matlab 指数积分

function dy=fun(x,y)dy=exp(-x) -1.5*exp(2*cos(2*pi*x));end%------------以上函数文件，保存名fun.m-------xx=-1:0.01:1;syms xidy=exp(-xi)-1.5*exp(2*cos(2*pi*xi));y0=double(subs(dy,0));=ode23(’fun’,xx,y0);ddy=subs(dy,x);plot(x,ddy,x,y,’r’)title(’红色为积分函数图’)

matlab中ployint的用法

1、polyint(p,k)，其中p是多项式系数组成的行向量，k是一个标量。这个函数的作用是对多项式p进行积分，把k作为积分后的常数项（因为对多项式积分后常数项不确定）。2、polyint(p)，作用和上面一样，默认k=0。例如：

p = ;    % p=x+1k1 = polyint(p)k1 = 0.5 1 0    % 积分结果为 0.5x^2 + x，常数项默认为0k = 1;k2 = polyint(p,k)k2 = 0.5 1 1    % 积分结果为 0.5x^2 + x + 1，常数项为k，即1

以上就是polyint的用法。

求mathematica积分或者用matlab也行

这个在mathematica里直接能算啊。。。结果是不定的。。。ConditionalExpression != -5 Re || 5 Im != 5 Re 《 0) && Im

怎么用Matlab编程计算积分！！！

intIntegratesymbolicexpressionSyntaxint(expr)int(expr,v)int(expr,a,b)int(expr,v,a,b)算了，给你举两个例子吧x^2积分：》》symsx;》》int(x^2,x)ans=x^3/3x^2从1积分到5：》》int(x^2,x,1,5)ans=124/3注意前面一句话，syms表示定义变量自己遇到问题多看手册或者自己谷歌，百度知道上面专业人士不多的

MATLAB计算两个变量的积分积分

dblquad(@(x,y)x*sin(y)+y*sin(x),-1,1,-1,1)ans = 0这是一个二重积分函数；triplequad()是三重积分函数！在Command 窗口下输入doc dblquaddblquad Numerically evaluate double integral Syntaxq = dblquad(fun,xmin,xmax,ymin,ymax)q = dblquad(fun,xmin,xmax,ymin,ymax,tol)q = dblquad(fun,xmin,xmax,ymin,ymax,tol,method