Legend function shows wrong colors.

Hi, i want to plot my curves with respect to time. However legend function assigns wrong color values to wrong colors. That is, it does not name them with the order gave to it.

Thanks for the help!

clc
clear all
close all

k_a=1/8;
k_b=0.2;
k_c=4;
k_g=0.1;
k_w=0.2;

h=0.2;

ti=0;
tf=100;
T=ti:h:tf;

S=zeros(length(T));
E=zeros(length(T));
I=zeros(length(T));
M=zeros(length(T));
R=zeros(length(T));

%%Some code.

plot(T,S)
hold on
plot(T,E)
hold on
plot(T,I)
hold on
plot(T,M)
hold on
plot(T,R)
hold on
legend('Suceptibles','Exposed','Infected','Medicaly Semptomatic','Recovered')

[Adam]

It would help if you posted the result of doing all that so we can see what the legend looks like. It seems fine to me when I run it.

[Oguz Munib Esen]

Thanks! Walter pointed out my mistake.

Answer 1

[Walter Roberson]

zeros(length(T)) is the same as zeros(length(T), length(T)) which is a 2D array.

k_a=1/8;
k_b=0.2;
k_c=4;
k_g=0.1;
k_w=0.2;
h=0.2;
ti=0;
tf=100;
T=ti:h:tf;
S=zeros(size(T));
E=zeros(size(T));
I=zeros(size(T));
M=zeros(size(T));
R=zeros(size(T));
S(1)=10000;
E(1)=10;
I(1)=0;
M(1)=0;
R(1)=0;
for i=1:length(T)-1
    
    S(i+1)=S(i)-h*((k_c*k_b*I(i)*S(i))/(S(i)+E(i)+I(i)+M(i)+R(i)));
    E(i+1)=E(i)+h*((k_c*k_b*I(i)*S(i))/(S(i)+E(i)+I(i)+M(i)+R(i))-(k_a*E(i)));
    I(i+1)=I(i)+h*((k_a*E(i))-(k_g*I(i)));
    M(i+1)=M(i)+h*((k_g*I(i))-(k_w*M(i)));
    R(i+1)=R(i)+h*((k_w*M(i)));
    
end
plot(T,S, 'b.-')
hold on
plot(T,E, 'k*-')
hold on
plot(T,I, 'r+-')
hold on
plot(T,M, 'c^-')
hold on
plot(T,R, 'gv-')
hold on
legend('Suceptibles','Exposed','Infected','Medicaly Semptomatic','Recovered')

[Oguz Munib Esen]

Thank you, So my mistake was defining NxN matrices instead of 1xN vectors.