How can I plug vector values into a matrix?

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ms38 2020-11-6

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回答： Sreeranj Jayadevan 2020-11-17

I have a matrix that depends on different x, y and z values. I want to put in different vector values in the matrix and make a series of calculations. How can I do this?

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Rik 2020-11-6

Do you mean you want to interpolate a 3D array? Can you provide a bit more explaination?

What have you tried?

ms38 2020-11-6

Hi Rik, thank you for your reply. I realise now my question may have been unclear. Basically I am investigating a system of 3D ODES. I have a Jacobian matrix and I want to input different vectors in the matrix, so I can calculate the eigenvalues of these matrices and then then eventually plot the trace of the matrix. I have created a for loop for a series of 1 x 3 vectors (up to a 1000 vectors) and now I want to put those vector values in the Jacobian matrix. How can I do this? (Apologies if my question is still a little unclear or silly, I'm new to MATLAB so I'm still learning what is possible and what isn't).

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Answer 1

Sreeranj Jayadevan 2020-11-17

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在 MATLAB Online 中打开

If 'Vec' is your 1000 by 3 vector and it is of the form

[x1 y1 z1;
 x2 y2 z2;
 x3 y3 z3;
 ........
 ........
 ........]

and since you are finding the Jacobian matrix, you can replace the variable x with Vec(i,1), y with Vec(i,2) and z with Vec(i,3) within the Jacobian matrix and then loop through the variable 'i'. (i=1,2,3.....1000)

You can also go through the "jacobian" function and check if it helps with the problem at hand: https://in.mathworks.com/help/symbolic/jacobian.html