Plot multiple lines + fmincon

Hi, I need to plot multiple lines in one graph, with different values of the the parameters.

The first line with value a=-0.02 and b=0.05;

The second line with value a=-0.05 and b=0.05;

Based on these values, I derived optimal solution and plot the optimal solutions.

see below the detailed codes of a single line in the graph with one set of a and b.

x0=[0,0,0,0];

m=2;a=-0.02;b=0.05;d=0.9;c=0.05;

f = @(x,r)(-x(1)*x(2)*(m-x(2)-c)-(1-x(1))*x(2)*(m-x(2)+(a+b)/2-c)-d*x(3)*x(4)*(m+x(1)*x(2)+(1-x(1))*x(2)*r-x(4)-c)-d*(1-x(3))*x(4)*(m+x(1)*x(2)+(1-x(1))*x(2)*r-x(4)+(a+b)/2-c))

r=0:0.05:1

for ii = 1:length(r)

x(:,ii),fval]=fmincon(@(x)f(x,r(ii)),x0,[],[],[],[],[0;0;0;0],[1;2;1;2])

end

plot(r,x(1,:))

title('Figure Title');

xlabel('x');

ylabel('y');