Plot call does not do its work properly.
조회 수: 1 (최근 30일)
이전 댓글 표시
I've been working in a project and every time I run this code in my computer it doesn't show the three graph it is suposed to graph. I have a function define and saved:
function [dydt] = spring_mass_system(t,y)
%Definition of 2nd order ODE for the spring-mass system
m = 20;
c(1)=5;
c(2)=40;
c(3)=200;
k = 20;
for i=1:3
dydt = zeros(2,1); %define colum array for output
dydt(1) = y(2);
dydt(2) = - (c(i)/m) * y(2) - (k/m) * y(1);
end
end
and I call my function by this script where I (supposedly) graph the three results in the the same picture. I run it in another computer and it does it how I want it. Any suggestion how to make this work properly, please? You can see I've added suggestion found online but, I it doesn't do anything to me.
tspan = [0,15];
ic = [0 1];
[t,y] = ode45(@spring_mass,tspan,ic);
figure;
plot(t,y(:,2));
grid;
xlabel('Time (s)');
ylabel('Dispalcement (m)');
hold on
thank you so much for your help.
댓글 수: 0
채택된 답변
Star Strider
2019년 12월 6일
The plot call you posted has it only plotting the second output of ‘spring_mass_system’.
It doesn’t show three lines because ‘spring_mass_system’ only returns two. That is how you wrote your ‘spring_mass_system’ ODE function.
댓글 수: 4
Star Strider
2019년 12월 6일
If you want to plot position, velocity, and acceleration as functions of time, you need to write your ‘spring_mass_system’ differential equations to provide them. That will give you the (Nx3) ‘y’ matrix you want.
Since this appears to be a homework assignment, I leave that to you.
추가 답변 (0개)
참고 항목
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!