Plotting with an injected numerical solution as an argument

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AtoZ 2018-12-4

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https://ww2.mathworks.cn/matlabcentral/answers/433721-plotting-with-an-injected-numerical-solution-as-an-argument

评论： AtoZ 2018-12-4

I have a numerical solution "a" of an equation which is obtained for a "specific value of T and k". I want to insert this solution inside a function which is then to be plotted.

In the plot function I also have same variables, and plot is for a "range of T values" (on x-axis) and fixed k. Now the numerical solution is only for a fixed T value, so it is not well synchronized with the plot function. Is there a way to tie these two (numerical solution+plot function), so I can define T and other same variables once and for all?

The code for numerical solution is

syms a
v2=-2.375; g=1; b=0.00001; e2=0.5; k=pi/2; T=1.1; w=-2*cos(k);
eqn = sin(3*k+a)/sin(2*k+a)==v2-w+(g.*T.^2)./(1+b.*T.^2)+(e2.*T.^2.*sin(k)^2)./(sin(2*k+a)^2+b*T.^2*sin(k)^2);
sol = solve(eqn,a,[0 pi]);
solutions=vpa(subs(sol),3)  

The above numerical solution(s) is to be injected inside the argument of `cosine` function below and then plotted. The code for plotting function is

v0=-2.5; epsilon=0.05; v1 = v0*(1+epsilon); v2 = v0*(1-epsilon); g = 1;
T=[0:0.01:3];
k=pi/2
l=-k
w=-2*cos(k)
w1=-2*cos(l)
 nu = @(T) v2-w+g.*T.^2;
 delta = @(T) v1-w+g.*T.^2.*(1-2.*nu(T)*cos(k+solutions)+nu(T).^2); 
  nu1 = @(T) v1-w1+g.*T.^2;
  delta1 = @(T) v2-w1+g.*T.^2.*(1-2.*nu(T)*cos(k+solutions)+nu(T).^2);
 fplot(@(T) abs((exp(i*k)-exp(-i*k))/(1+(nu(T)-exp(i*k)).*(exp(i*k)-delta(T))))^2,[0,5],'--r')
 hold on
 fplot(@(T) abs((exp(i*l)-exp(-i*l))/(1+(nu1(T)-exp(i*l)).*(exp(i*l)-delta1(T))))^2,[0,5],'b')
 hold off
 legend('k=\pi/2','k=-\pi/2')