MATLAB: Dsolve issue with solving nasty system of ODEs

dsolveodeode systemode'ssystem of differential equations

Dear all,
I've been having this issue for a while where, I can't find a solution for the following system of ODEs:
   % Inputs for the stiffness matrix
 X1= -138.7840e-024;
 X2= 123.0769e+003;
 X3= -61.5385e+003; 
 % The stiffness matrix:
 A=[X1   0   0   0;
    0   X2  X3  X3;
    0   X3  X2  X3;
    0   X3  X3  X2];
 % Defining the ODEs
 syms x(t) y(t) z(t) w(t)
 Y=[x; y; z; w];   
 Q=[x; x*y; x*z; x*w];   %Multiplied by the stiffness matrix
 i = Y(0) == [16.0746; 12.9888; -5; 0]; % Initial conditions 
 odes=diff(Y) == A*Q;
 [xSol(t), ySol(t), zSol(t), wSol(t)]= dsolve(odes, i);
 %Display solution at 10^10
 display(double(xSol(10^10)));
 display(double(ySol(10^10)));
 display(double(zSol(10^10)));
 display(double(wSol(10^10)));
This is the output message I keep getting:
     Warning: Explicit solution could not be found. 
> In dsolve (line 201)
  In question_for_forum (line 16) 
Error using sym/subsindex (line 732)
Invalid indexing or function definition. When defining a function, ensure that the
arguments are symbolic variables and the body of the function is a SYM expression.
When indexing, the input must be numeric, logical, or ':'.
Error in question_for_forum (line 16)
 [xSol(t), ySol(t), zSol(t), wSol(t)]= dsolve(odes, i);
Any help will be much appreciated,
Thank you
P.S. I tried to follow these guides, but something I must be doing wrong: http://uk.mathworks.com/help/symbolic/solve-a-single-differential-equation.html
https://uk.mathworks.com/help/symbolic/solve-a-system-of-differential-equations.html

Best Answer

Your system is too complicated to be solved symbolically.
Use a numerical solver instead, e.g. ODE15S.
Best wishes
Torsten.
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