Errors in passing a constant to a function in boundary value problem (bvp4c function)

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Amit Kumar
Amit Kumar 2014-3-24
评论： Amit Kumar 2014-3-26
Hello all, I am trying to solve a boundary value problem and I wish to pass value of variable E to odefunction() and bcfunction(), instead of declaring E separately in 2 different functions. Anyone has any suggestion? Or can't we pass constants for the function?
function [] = bvp3
% AEd2y/dx2 + 10Ax = 0; 0<x<2
%y(0)=1e-4, E*(dy/dx)=10 x=2
clc;
clear all;
close all;
%%function script
xmin=0;
xmax=2;
A=100;
%global E
E=2e5;
solinit = bvpinit(linspace(xmin,xmax,100),[-5,5]);
solution=bvp4c(@odefunction,@bcfunction,solinit);
xvar=linspace(xmin,xmax,1000);
desolution=deval(solution,xvar);
figure(1);
plot(xvar,desolution(1,:),'-k');
hold on;
plot(xvar,desolution(2,:),':k');
hold off;
title('sol');
legend('y','d^{2}y/dx^{2}');
xlabel('x');
ylabel('y');
end
%%ODE function
function odevector = odefunction(x,y,E)
%E=2e5;
odevector = [y(2),(-10/E)*x];
end
%%BC function
function bcvector = bcfunction(ya,yb,E)
%E=2e5;
bcvector = [ya(1)-1e-4,yb(2)-(10/E)];
end

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采纳的回答

Mischa Kim
Mischa Kim 2014-3-25
编辑：Mischa Kim 2014-3-25
Amit, replace this one command
solution = bvp4c(@odefunction,@bcfunction,solinit);
by
options = [];
solution = bvp4c(@odefunction,@bcfunction,solinit,options,E);
Of course, you can use options to control the solver via bvpset.
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Mischa Kim
Mischa Kim 2014-3-26
I just checked, the function works as expected with my suggested changes with the lastest releases all the way back to R2012b, see attachment.
  • What release are you working with?
  • What're the error messages?
Amit Kumar
Amit Kumar 2014-3-26
Hi Mischa, Thanks for your reply. Your method did work. It was mistake from my side. Thanks a lot!

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