How to avoid syms in Simulink

Question

Pu 2014-12-1

2
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https://ww2.mathworks.cn/matlabcentral/answers/165000-how-to-avoid-syms-in-simulink

回答： Sean de Wolski 2014-12-1

I need to solve the following 27 equations using fsolve in Simulink for each time step. So I cannot wait until it is exported to Matlab Workspace. But Matlab Function Blocks in Simulink cannot handle the syms. Is there any way to avoid it. Below is the function in my Matlab Function Block in Simulink. Thank you so much!

A = sym('A', [3 9]);
Coor=sym('B',[27,1]);
%Lower Octahedral
Coor(1)=transpose(A(:,4)-A(:,3))*(A(:,4)-A(:,3))-l^2;
Coor(2)=transpose(A(:,4)-A(:,1))*(A(:,4)-A(:,1))-l^2;
Coor(3)=transpose(A(:,4)-A(:,5))*(A(:,4)-A(:,5))-qt(1)^2;
Coor(4)=transpose(A(:,5)-A(:,1))*(A(:,5)-A(:,1))-l^2;
Coor(5)=transpose(A(:,5)-A(:,2))*(A(:,5)-A(:,2))-l^2;
Coor(6)=transpose(A(:,5)-A(:,6))*(A(:,5)-A(:,6))-qt(2)^2;
Coor(7)=transpose(A(:,6)-A(:,3))*(A(:,6)-A(:,3))-l^2;
Coor(8)=transpose(A(:,6)-A(:,2))*(A(:,6)-A(:,2))-l^2;
Coor(9)=transpose(A(:,6)-A(:,4))*(A(:,6)-A(:,4))-qt(3)^2;
%Upper Octahedral
Coor(10)=transpose(A(:,7)-A(:,4))*(A(:,7)-A(:,4))-l^2;
Coor(11)=transpose(A(:,7)-A(:,5))*(A(:,7)-A(:,5))-l^2;
Coor(12)=transpose(A(:,7)-A(:,8))*(A(:,7)-A(:,8))-qt(4)^2;
Coor(13)=transpose(A(:,8)-A(:,5))*(A(:,8)-A(:,5))-l^2;
Coor(14)=transpose(A(:,8)-A(:,6))*(A(:,8)-A(:,6))-l^2;
Coor(15)=transpose(A(:,8)-A(:,9))*(A(:,8)-A(:,9))-qt(5)^2;
Coor(16)=transpose(A(:,9)-A(:,6))*(A(:,9)-A(:,6))-l^2;
Coor(17)=transpose(A(:,9)-A(:,4))*(A(:,9)-A(:,4))-l^2;
Coor(18)=transpose(A(:,9)-A(:,7))*(A(:,9)-A(:,7))-qt(6)^2;
%r1 r2 & r3 are known
Coor(19)=A(1,1)-sqrt(3)*l/4;
Coor(20)=A(2,1);
Coor(21)=A(3,1);
Coor(22)=A(1,2)+A(1,1);
Coor(23)=A(2,2)-l/2;
Coor(24)=A(3,2);
Coor(25)=A(1,3)-A(1,2);
Coor(26)=A(2,3)+l/2;
Coor(27)=A(3,2);
%Use fsolve to solve the system based on current value of q
[result, fval, exit, output]=fsolve(Coor,guess);