how to get multiple lines on a plot with ode45 and for loop?

Question

nick Gangi 2016-8-3

0
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https://ww2.mathworks.cn/matlabcentral/answers/298351-how-to-get-multiple-lines-on-a-plot-with-ode45-and-for-loop

回答： Walter Roberson 2016-8-4

I'm modeling a mass spring damper system and I'm trying to get multiple lines on the plot for each different damping coefficient value and I can only get one line for the first value. my code is a bit mess but here it is.

clear 
clc
g=9.81; %m/s^2
m=1179/4; % mass of a honda civic kg
L=1; %Distance traveled meters
t=0:.001:3;
y_0=0;
dydt_0=0;
k=(m*g)/.1; %spring constant N/m
v_0=20; %velocity m/s
%x=v_0*t;
f=250; %load in kg
%z=.5;
z=[0 .1 .2 .25 .35 .5 .65 .75 .9 1]; %damping factor ranges 
wn=(k/m)^.5; %natural frequency
c=2*m*wn.*z; %damping coeff
wd=wn*(1-z.^2).^.5; %damped natural freq
hold on
for i=1:10
[t,y]=ode45(@EOMM,t,[y_0 dydt_0]);
plot(t,y(:,1))
grid on
xlabel('Time(s)')
ylabel('Deflection(m)')
end
    % function
function [ dydt ] = EOMM(t,y)
%UNTITLED8 Summary of this function goes here
%   Detailed explanation goes h
g=9.81; %m/s^2
m=1179/4; % mass of a honda civic kg
L=1; %Distance traveled meters
t=0:.001:3;
y_0=0;
dydt_0=0;
k=(m*g)/.1; %spring constant N/m
v_0=20; %velocity m/s
f=250; %load in kg
%z=.5;
z=[0 .1 .2 .25 .35 .5 .65 .75 .9 1]; %damping factor ranges 
wn=(k/m)^.5; %natural frequency
c=2*m*wn.*z; %damping coeff
    for i=1:10       
    dydt_1=y(2);
    dydt_2(i)=(1/m)*(f-c(i)*y(2)-k*y(1));
    dydt=[dydt_1;dydt_2(i)];
    end
end