Matlab图例修改

Question

Matlab修改图例

for i=0:0.1:0.9
    for j=0.2
D=7;gamma=0.2;C=8
dfun=@(t,x)[ x(1)*(1-x(1))*(4.2*x(2)+2.35-D); x(2)*(1-x(2))*(-2.7*x(1)-(0.5-gamma)*C+2.1)]
[T,Y] = ode45( dfun,[0 10],[i j]);
grid on
plot(T,Y(:,1),'r-'); 
hold on
    end
end
for i=0:0.1:0.9
    for j=0.9
D=7;gamma=0.2;C=8
dfun=@(t,x)[ x(1)*(1-x(1))*(4.2*x(2)+2.35-D); x(2)*(1-x(2))*(-2.7*x(1)-(0.5-gamma)*C+2.1)]
[T,Y] = ode45( dfun,[0 10],[i j]);
grid on
plot(T,Y(:,1),'b--');
hold on
    end
end
xlabel('t')
ylabel('x')

上面是代码，下面是原图

想弄成如下图例的形式，请问怎么修改图例代码？

Answer 1

加入图例和文本

% Parameters
D = 7; 
gamma = 0.2; 
C = 8;
% Create figure
figure;
hold on;
% Loop for plotting y with j = 0.2 (red solid line)
for i = 0:0.1:0.9
    j = 0.2;  % Set j to 0.2
    dfun = @(t,x)[ x(1)*(1-x(1))*(4.2*x(2)+2.35-D); x(2)*(1-x(2))*(-2.7*x(1)-(0.5-gamma)*C+2.1)];
    [T,Y] = ode45(dfun,[0 10],[i j]);
    plot(T,Y(:,1),'r-');  % Red solid line
    j1 = 0.9;  % Set j to 0.9
    dfun1 = @(t,x)[ x(1)*(1-x(1))*(4.2*x(2)+2.35-D); x(2)*(1-x(2))*(-2.7*x(1)-(0.5-gamma)*C+2.1)];
    [T1,Y1] = ode45(dfun1,[0 10],[i j1]);
    plot(T1,Y1(:,1),'b--');  % Blue dashed line
end
hold off;
% Labels for axes
xlabel('t');
ylabel('x');
% Add legend with specific descriptions for y values
legend('y = 0.2', 'y = 0.9', 'Location', 'best');
% Add additional text annotations for alpha and xi
text(3, 0.8, '\alpha = 0.3,\xi = 0.85','FontSize',12,'Color','k');