Plotting help. No line or points appearing on plot

So, im trying to write a script to plot x=x1 + tV1cos(theta). The figure will generate but no points. What can I do to fix this? Any help would be extremely appreciated. Thank you in advance

%% Get user input

launch_angle= input('Enter launch angle in degrees : ');

xo = input('Enter initial x position in meters: ');

xt = input('Enter target x position in meters: ');

yt = input('Enter target y position in meters: ');

tt = input('Enter target hitting time in seconds: ');

te = input('Enter end time in seconds: ');

g=9.8;

% Calculate Vo

vo = (xt-xo)/(tt*(cos(launch_angle * (pi/180))))

%% Display the result

disp(['Initial Velocity in metres per second is: ', num2str(vo)]);

%% Calculate yo

yo = yt - (tt*vo*(sin(launch_angle * (pi/180))))+(0.5*g*tt^2)

%% Display the result

disp(['Initial y positon in metres is: ', num2str(yo)]);

%% Equations to plot End pt

xe = xo + (te*vo*cos(launch_angle * (pi/180)))

ye = yo + (te*vo*(sin(launch_angle * (pi/180))))-(0.5*g*te^2)

%% Plot end point

figure

plot(xe',ye','-r');

[Mathieu NOE]

Hi

I suspect you wanted to plot the full trajectory, but you're simply plotting one (the end) point

If you don't see it maybe it's because you have not choosen the right options : try : plot(xe',ye','*r');

nvertheless, you have to write the equation of the trajectory first before you can plot it

Answer 1

[VBBV]

You need to make time as vector. Then you can plot the trajectory, if i understand it right.

See the code below, it plots xe vs ye according to your prog

launch_angle= input('Enter launch angle in degrees : ');
xo = input('Enter initial x position in meters: ');
xt = input('Enter target x position in meters: ');
yt = input('Enter target y position in meters: ');
tt = input('Enter target hitting time in seconds: '); % total time to hit target in s
te = input('Enter end time in seconds: '); % end time at which target is destroyed
g=9.8;
te = tt:-0.1:te;   % calculate the time vector
% Calculate Vo
vo = (xt-xo)/(tt*(cos(launch_angle * (pi/180))))
 
%% Display the result
disp(['Initial Velocity in metres per second is: ', num2str(vo)]);

%% Calculate yo
yo = yt - (tt*vo*(sin(launch_angle * (pi/180))))+(0.5*g*tt^2)
%% Display the result
disp(['Initial y positon in metres is: ', num2str(yo)]);
 
%% Equations to plot End pt
 
xe = xo + (te*vo*cos(launch_angle * (pi/180)))
ye = yo + (te*vo*(sin(launch_angle * (pi/180))))-(0.5*g*te.^2)
 
%% Plot end point
 
figure
plot(xe',ye','-r');