Symbolically solving vectors simultaneously
显示 更早的评论
Hello, I have been trying to solve a vector using the symbolic toolbox and am running into an error that says "Error using maplemex
Error, (in MTM:-solve) 0 variables do not match undefined outputs.", I am currently trying to solve for a variable in a matrix that is equal to zero, below is an example.
syms q0
moment=[5*q0+25 6*q0+45 5*q0+45]
[q0]=solve(moment==0)
This specific example is solving moment equilibrium for a monocoque structure.
Is there a way to solve the seperate q0 values so its a vector like [q0_1 q0_2 q0_3] using the symbolic toolbox?
Thanks!!!
采纳的回答
One solve statement (such as in the original post) also fails in R2022a. One option to get all of the solutions is arrayfun that should be available (another is an explicit loop) —
syms q0
moment = [5*q0+25 6*q0+45 5*q0+45];
q0 = arrayfun(@(x)solve(x), moment)
.
5 个评论
Ramses Young
2022-4-30
Unfortunately, I cannot test my code in R2018a.
Option 2 —
syms q0
moment = [5*q0+25 6*q0+45 5*q0+45];
for k = 1:numel(moment)
q0(k) = solve(moment(k));
end
q0
.
Walter Roberson
2022-4-30
arrayfun() might not be able to work with Maple sym, so using a loop might be the best.
Ramses Young
2022-5-1
Star Strider
2022-5-1
As always, my pleasure! (And thanks to Walter for his observations.)
更多回答（1 个）
q0 = sym('q0_',[1 3])
moment=[5*q0(1)+25 6*q0(2)+45 5*q0(3)+45]
solve(moment==0,q0)
2 个评论
Walter Roberson
2022-4-30
I do not recall whether the interface to maple supports using sym that way to create a vector. Maybe?
Ramses Young
2022-4-30
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