integral2 error, bu the function works

1 次查看（过去 30 天）
Xiangyu Meng
Xiangyu Meng 2017-2-10
回答： Carlos Guerrero García 2022-11-26
fun = @(x,y) 1-exp(-0.01*norm(x-y));
q = integral2(fun,0,1,0,1);
It gives me the following error:
Error using integral2Calc>integral2t/tensor (line 241)
Integrand output size does not match the input size.
Error in integral2Calc>integral2t (line 55)
[Qsub,esub] = tensor(thetaL,thetaR,phiB,phiT);
Error in integral2Calc (line 9)
[q,errbnd] = integral2t(fun,xmin,xmax,ymin,ymax,optionstruct);
Error in integral2 (line 106)
Q = integral2Calc(fun,xmin,xmax,yminfun,ymaxfun,opstruct);
Error in IntegrateTriangularRegionwithSingularityattheBoundaryExample (line 19)
q = integral2(fun,0,1,0,ymax)
The function fun is well defined and tested. Work for both scalar and vector.
How to make the integral work?
[SL: edited to format code]

请先登录，再回答此问题。

回答（2 个）

Steven Lord
Steven Lord 2017-2-10
What does the integral2 function require of the integrand function you specify as its first input?
"The function fun must accept two arrays of the same size and return an array of corresponding values. It must perform element-wise operations."
What does your function do?
fun = @(x,y) 1-exp(-0.01*norm(x-y));
x = 1:10;
y = x+1;
z = fun(x, y)
Is z the same size as x and y? I think something closer to what you want is:
fun = @(x,y) 1-exp(-0.01*abs(x-y));
x = 1:10;
y = x+1;
z = fun(x, y)
  2 个评论
Xiangyu Meng
Xiangyu Meng 2017-2-10
I want to calculate the integral of the function fun in the planar [0,1]*[0,1].
Torsten
Torsten 2017-2-13
As Steven suggested, replace "norm" with "abs" in your function definition.
Best wishes
Torsten.

请先登录，再进行评论。

Carlos Guerrero García
Ran in:
A sketch of the function:
[x,y]=meshgrid(0:0.01:1); % The region in the statement
surf(x,y,1-exp(-0.01*abs(x-y))); % Plotting the surface
shading interp % For a nice view
and the integral can be calculated as follows:
syms x y; int(int(1-exp(-0.01*abs(x-y)),0,1),0,1)
ans = 

类别

在 Help Center 和 File Exchange 中查找有关 Numerical Integration and Differentiation 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by