need help with problem
显示 更早的评论
what is wrong in this code i dont get the correct answer
xleft=0;
xright=(9*pi)/4;
N=20;
x=linspace(xleft,xright,N);
x=x';
dx=(xright-xleft)/(N-1);
yleft=1;
yright=1;
a=1;
b=-2;
c=-2;
% M is the matrix when multiplied by y gives y'' y' and y
M2=(diag(-2*ones(N,1),0)+diag(ones(N-1,1),-1)+diag(ones(N-1,1),1))/dx^2;
M1=(diag(ones(N-1,1),1)-diag(ones(N-1,1),-1))/(2*dx);
M0=eye(N);
M=a*M2+b*M1+c*M0;
%treating boundaries separate
M(1,:)=[1,zeros(1,N-1)];
M(end,:)=[zeros(1,N-1),1];
k=(sin(x))/((cos(x))+2);
k(1) = yleft;
k(end) = yright;
y=M\k
采纳的回答
Matt J
2019-4-3
1 个投票
is my code correct i dont get the correct answer
Then by definition, it is not correct...
更多回答（1 个）
Muhammad Ibrahim
2019-4-4
编辑：Muhammad Ibrahim
2019-4-4
1 个投票
k=(sin(x))/((cos(x))+2);
should be
k=(sin(x))./((cos(x))+2);
That small dot after sin(x) can make a big difference.
Also. read the question carefully, you might be keying the maximum value when it maybe asking minimum value.If you still have problems just ask again in this forum maybe I can help out.
类别
在 帮助中心 和 File Exchange 中查找有关 Surrogate Optimization 的更多信息
Translated by 
