GUI plot for projectile motion not reproducing trajectory

Question

Ryan Schofield 2019-2-2

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442773-gui-plot-for-projectile-motion-not-reproducing-trajectory

评论： Ryan Schofield 2019-2-3

When I try to plot my projectile motion function, the GUI plot does not display the entire trajectory as it does when I run the function in regular MATLAB. Instead it displays the projectile (dot) moving along while the y-axis constantly shifts to capture the height of the projectile. I would the entire trajectory to be displayed and also not have the y-axis shift so frantically. Below is the code in the GUI and after that, the code from the MATLAB function.

angle = app.angle.Value;
            x0    = app.x0.Value;
            y0    = app.y0.Value;
            v0    = app.v0.Value;
            
            g = 9.81;
            hangtime = 2*v0*sind(angle)/g;
            t = 0:hangtime/100:hangtime;
            vix = v0*cosd(angle);
            viy = v0*sind(angle);
            x = x0+vix*t;
            y = y0+viy*t-(g*t.^2)/2;
            maxheight = y0 + (viy)^2./(2*g)
            xheight = x0 + vix*(t/2);
            
            for k=2:length(t)
               x(k) = x0 +(vix*t(k));
               y(k) = y0 +(viy*t(k))-0.5*g*t(k)^2;
               h = plot(app.UIAxes,x(k),y(k),'.');
               hold(app.UIAxes);
               set(h,'MarkerSize',10);
               set(h,'Color',[0.1,0.3,1]);
               pause (0.02);
           end
           end
           

Now this is the original function code:

function projmotion(x0,y0,v0,theta)
% projmotion calculates projectile motion
%
% projmotion(x0,y0,v0,theta)
%
% x0 = initial x(horizontal) position
% y0 = initial y(vertical) position
% v0 = initial velocity
% theta = angle of launch
% 
% Ver 1.0 by RSS
g = 9.81;
angle = theta*(pi./180);
hangtime = 2*v0*sin(angle)/g;
t = hangtime;
vix = v0*cos(angle);
viy = v0*sin(angle);
x = x0+vix*t;
y = y0+viy*t-(g*t.^2)/2;
maxheight = y0 + (viy)^2./(2*g)
xheight = x0 + vix*(t/2);
if theta >90
    error('Please select angle value of 90 degrees or less')
end;
figure('Color', [1 1 1]);
for k=0:t/100:t
    x = x0 +(vix*k);
    y = y0 +(viy*k)-0.5*g*(k^2);
end
  
for k=0:t/100:t
    x = x0 +(vix*k);
    y = y0 +(viy*k)-0.5*g*(k^2);
    h = plot(x,y,'.');
    xlabel('Horizontal Distance (meters)');
    ylabel('Height (meters)');
    title('Trajectory Time');
    set(h,'MarkerSize',10);
    set(h,'Color',[1,0.3,0.5]);
    hold on;
    pause(0.02);
    
end
s1 = sprintf('Total time of travel is %f seconds.\n', t)
s2 = sprintf('Range is %f meters.\n', x-x0)
s3 = sprintf('Max height is %f meters.\n', maxheight)
s4 = sprintf('X position at max height is %f meters.\n', xheight)
message = sprintf('%s%s%s%s%s%s%s%s',s1, s3, s2, s4);
uiwait(helpdlg(message, 'Simulation Results'));