Solve a nonlinear system.

I would like to solve this system. It gives no solution when it is suposed to.

This is the code:

syms s t  
Q_estim1=[-1 1;2 -2];

h1=diag([1 2]); prob_perd=0.01; b=2;

aux=expm(Q_estim1*100);
pi_inf1=aux(1,:);

alfa1=log(pi_inf1*expm((Q_estim1+h1*s)*t)*ones(2,1))*1/(s*t);

eq1=diff(alfa1,s);
eq2=diff(alfa1,t);

solve('eq1-prob_perd/(s^2*t)','eq2-prob_perd/(s*t^2)-b/t^2')

I don't need analytic solution. Any help will be gratly apreciated.

[bym]

what is the variable prob_perd ? is it symbolic?

[José Bavio]

prob_perd is constant.

[bym]

ah...right

you are mixing floating point and symbolic operations which can lead to trouble. Best to use symbolic to a point then use subs() to plug in numerical values

Answer 1

[Walter Roberson]

When you pass a literal string to solve() then values set at the MATLAB level will not be substituted in. Remove the quotes.

solve(eq1-prob_perd/(s^2*t),eq2-prob_perd/(s*t^2)-b/t^2)