How to avoid syms in Simulink

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Pu
Pu on 1 Dec 2014
Answered: Sean de Wolski on 1 Dec 2014
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);

Answers (1)

Sean de Wolski
Sean de Wolski on 1 Dec 2014
Since you're not generating code from it, you could use the "Interpretted MATLAB Function Block" which should allow for the use of syms.

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