Hi everyone,
For an assignment I have to solve a system of ODE’s given the matrix DE using the Adams-Bashforth method and compare my numerical approximation to the exact one. To find the exact solution, I want to use dsolve, but every I run my code I get the error message ‘Unexpected MATLAB expression’ and then ‘Parse Error at Y_2(t): Usage might be invalid MATLAB syntax’. I am using MATLABR2017.

Does anyone know what the issue is?

function Y_exact = exact_soln(time)
%Actual solution to the system:
A = [-20, 10, 0, 0;…
10, -20, 10, 0;…
0, 10, -20, 10;…
0, 0, 10, -20];
y_0 = ones(4,1);

syms = Y_1(x) Y_2(x) Y_3(x) Y_4(x)
Y = [Y_1; Y_2; Y_3; Y_4];
odes = diff(Y) == A*Y;

[Y_1Sol(x), Y_2Sol(x), Y_3Sol(x), Y_4Sol(x)] = dsolve(odes,y_0);

Y_exact = [double(Y_1Sol(time));…
double(Y_2Sol(time));…
double(Y_3Sol(time));…
double(Y_4Sol(time))];
endHi everyone,
For an assignment I have to solve a system of ODE’s given the matrix DE using the Adams-Bashforth method and compare my numerical approximation to the exact one. To find the exact solution, I want to use dsolve, but every I run my code I get the error message ‘Unexpected MATLAB expression’ and then ‘Parse Error at Y_2(t): Usage might be invalid MATLAB syntax’. I am using MATLABR2017.

Does anyone know what the issue is?

function Y_exact = exact_soln(time)
%Actual solution to the system:
A = [-20, 10, 0, 0;…
10, -20, 10, 0;…
0, 10, -20, 10;…
0, 0, 10, -20];
y_0 = ones(4,1);

syms = Y_1(x) Y_2(x) Y_3(x) Y_4(x)
Y = [Y_1; Y_2; Y_3; Y_4];
odes = diff(Y) == A*Y;

[Y_1Sol(x), Y_2Sol(x), Y_3Sol(x), Y_4Sol(x)] = dsolve(odes,y_0);

Y_exact = [double(Y_1Sol(time));…
double(Y_2Sol(time));…
double(Y_3Sol(time));…
double(Y_4Sol(time))];
end Hi everyone,
For an assignment I have to solve a system of ODE’s given the matrix DE using the Adams-Bashforth method and compare my numerical approximation to the exact one. To find the exact solution, I want to use dsolve, but every I run my code I get the error message ‘Unexpected MATLAB expression’ and then ‘Parse Error at Y_2(t): Usage might be invalid MATLAB syntax’. I am using MATLABR2017.

Does anyone know what the issue is?

function Y_exact = exact_soln(time)
%Actual solution to the system:
A = [-20, 10, 0, 0;…
10, -20, 10, 0;…
0, 10, -20, 10;…
0, 0, 10, -20];
y_0 = ones(4,1);

syms = Y_1(x) Y_2(x) Y_3(x) Y_4(x)
Y = [Y_1; Y_2; Y_3; Y_4];
odes = diff(Y) == A*Y;

[Y_1Sol(x), Y_2Sol(x), Y_3Sol(x), Y_4Sol(x)] = dsolve(odes,y_0);

Y_exact = [double(Y_1Sol(time));…
double(Y_2Sol(time));…
double(Y_3Sol(time));…
double(Y_4Sol(time))];
end dsolve, syms, parse error, invalid matlab syntax, unexpected matlab syntax, diff, odes MATLAB Answers — New Questions

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