3 equations 4 unknowns

3 次查看（过去 30 天）
Jens Petit-jean
Jens Petit-jean 2020-12-13
评论： Jens Petit-jean 2020-12-13
hello,
How do you make a matrix M 3x3 so the system is =k.MX (with X a 3x1 matrix [x,y,z] I think.)
x=k.(1.y+6.z)
y=k.(4.x+4z)
z=k.(0.x+1.y)
  2 个评论
Cris LaPierre
Cris LaPierre 2020-12-13
编辑：Cris LaPierre 2020-12-13
Does a period (1.y) mean multiplication (1*y)?
Also, I see 4 unknowns (k, x, y, z).
Jens Petit-jean
Jens Petit-jean 2020-12-13
yes the point means * sorry
and yes made a mistake I mean 4

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2020-12-13
Ran in:
%x=k.(1.y+6.z)
%y=k.(4.x+4z)
%z=k.(0.x+1.y)
syms x y z k
X = [x; y; z];
eqn = X == k * [0 1 6; 4 0 4; 0 1 0] * X
eqn = 
sol = solve(eqn, [x, y, z])
sol = struct with fields:
x: [1×1 sym] y: [1×1 sym] z: [1×1 sym]
sol.x
ans = 
0
sol.y
ans = 
0
sol.z
ans = 
0

更多回答（1 个）

Bruno Luong
Bruno Luong 2020-12-13
编辑：Bruno Luong 2020-12-13
>> M=[0 1 6; 4 0 4; 0 1 0];
>> [X,K]=eig(M);
>> k=1./diag(K);
% select 3rd eigen vector for example
>> X(:,3)
ans =
0.5508
0.8070
0.2131
>> k(3)*M*X(:,3)
ans =
0.5508
0.8070
0.2131

类别

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

标签

Community Treasure Hunt

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

Start Hunting!

Translated by