How can I show a graph from the function?
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Nc=100;
c = linspace(10,60,Nc)
function [t,th,pass] = lab1(c0,k0)
J=20;
opt=[];
F0=0;
omega=0;
dt=0.01; % sampling time interval
npt=2000; % number of sampling points
tspan=(1:npt)*dt; % time instants where x(t) is simulated
idx=0;
pass=[];
th_lim1=65/180*pi; % [rad]
th_lim2=3/180*pi; % [rad]
b_max=3.5; % [rad/s]
k=k0;
for i=1:length(c0)
for j=1:length(k0)
ctmp=0;
ktmp=0;
c=c0(i);
k=k0(j);
th0=[0;b_max];
[t,th]=ode45(@sdof,tspan,th0,opt,J,c,k,F0,omega);
end
end
end
function G=sdof(t,x,J,c,k,F0, omega)
the code above are function .
G=[x(2);(-c*x(2)-k*x(1)+F0*cos(omega*t)//J];
end
This code below is the plotting for the function .
plot(t,th(:,1)*180/pi)
title('Displacement vs Time of a Swinging Door')
xlabel('Time(Seconds)')
ylabel('Displacement(Degrees)')
plot([0,20],[1,2]*(65));
Attempt to execute SCRIPT lab1 as a function:
C:\Users\joe_p\Desktop\mec721\lab1.m
Error in lab1 (line 1)
[t,th,pass]=lab1(10,30)
That is error .
Please someone explain why i keep getting this error and explain how i can get the graph to work.
回答（2 个）
VBBV
2022-1-31
G=[x(2);(-c*x(2)-k*x(1)+F0*cos(omega*t)/J]; % seems you have used // erroneously
end
it is a division operator unlike a comment in C++ language
4 个评论
Call the function from command window instead of running from script
>>lab1(10:60,30:60)
Perry fung
2022-1-31
Perry fung
2022-1-31
Nc=10;
c0 = linspace(10,60,Nc);
k0 = linspace(0,20,Nc/2);
[t,th,pass] = lab1(c0,k0)
plot(t,th(:,1)*180/pi)
title('Displacement vs Time of a Swinging Door')
xlabel('Time(Seconds)')
ylabel('Displacement(Degrees)')
function [t,th,pass] = lab1(c0,k0)
J=20;
opt=[10; 20];
F0=0;
omega=0;
dt=0.01; % sampling time interval
npt=2000; % number of sampling points
tspan=(1:npt)*dt; % time instants where x(t) is simulated
idx=0;
pass=[];
th_lim1=65/180*pi; % [rad]
th_lim2=3/180*pi; % [rad]
b_max=3.5; % [rad/s]
k=k0;
for i=1:length(c0)
for j=1:length(k0)
ctmp=0;
ktmp=0;
c=c0(i);
k=k0(j);
th0=[0;b_max];
[t,th]=ode45(@(th0,opt) sdof(th0,opt,J,c,k,F0,omega),tspan,[0 1]);
end
end
function G=sdof(t,x,J,c,k,F0, omega)
G=[x(2);-c*x(2)-k*x(1)+F0*cos(omega*t)/J];
end
end
Image Analyst
2022-1-31
Attach your whole m-file.
You can't have a script followed by functions unless the functions end with "end", which yours don't. Your for loops end with end but the functions don't. Here is your script:
Nc=100;
c = linspace(10,60,Nc)
Notice that the script never even calls any of the functions defined below it in the file.
The m-file should look like
Nc=100;
c0 = linspace(10,60,Nc)
k0 = 1; % Whatever...
% Now call the main function:
[t,th,pass] = lab1(c0,k0)
% Now define all your functions AFTER your script
% and finish each one with an "end" statement.
%=====================================================================================
function [t,th,pass] = lab1(c0,k0)
% Its code...
end % Need final closing end statement
%=====================================================================================
function G=sdof(t,x,J,c,k,F0, omega)
% Its code...
end % Need final closing end statement
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2022-1-31
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