Bouncing Ball Animation Getframe

Question

Gabrielle Bartolome 2020-10-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/632604-bouncing-ball-animation-getframe

评论： Alan Stevens 2020-11-1

I don't understand what I am doing wrong. I have to create an animation of a ball bouncing. But I have to repeat a for loop for each bounce. It also plays the animation twice. Is there a simpler way of doing this? Also, is there a way to speed up the code so that the animation does not play so slowly? I was thinking that I could write a function that would call it to repeat the animation but I am not sure.

%%Animation 
clc, clf, clear
g = 9.81; 
theta0 = 45*pi/180; 
v0=5; 
t(1) = 0; x = 0; y = 0; 
plot(x,y, 'o', 'MarkerFaceColor','b', 'MarkerSize', 8)
axis([0 8 0 .8]); 
dt = 1/128;
M(1) = getframe
for j = 2:100
    t(j) = t(j - 1) + dt; 
    x = v0*cos(theta0)*t(j); 
    y = v0*sin(theta0) * t(j) - 0.5*g*t(j)^2; 
    plot(x,y, 'o', 'MarkerFaceColor', 'b','markerSize', 8);
    axis([0 8 0 .8]);
    M(j)= getframe; 
     
end
M(2) = getframe
t(100) = 0;
v0 = v0*.8;
for j = 101:198
    t(j) = t(j - 1) + dt; 
    x = v0*cos(theta0)*t(j)+2.5; 
    y = v0*sin(theta0) * t(j) - 0.5*g*t(j)^2; 
    plot(x,y, 'o', 'MarkerFaceColor', 'b','markerSize', 8);
    axis([0 8 0 .8]);
    M(j)= getframe; 
    
end 
M(3) = getframe
v0 = v0*.8;
t(198) = 0; 
for j = 199:300
    t(j) = t(j - 1) + dt; 
    x = v0*cos(theta0)*t(j)+4; 
    y = v0*sin(theta0) * t(j) - 0.5*g*t(j)^2; 
    plot(x,y, 'o', 'MarkerFaceColor', 'b','markerSize', 8);
    axis([0 8 0 .8]);
    M(j)= getframe; 
    
end 
M(4) = getframe
v0 = v0*.8;
t(300) = 0; 
for j = 199:300
    t(j) = t(j - 1) + dt; 
    x = v0*cos(theta0)*t(j)+4; 
    y = v0*sin(theta0) * t(j) - 0.5*g*t(j)^2; 
    plot(x,y, 'o', 'MarkerFaceColor', 'b','markerSize', 8);
    axis([0 8 0 .8]);
    M(j)= getframe; 
    
end 
movie(M, 1, 1000)

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Answer 1

Alan Stevens 2020-11-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/632604-bouncing-ball-animation-getframe#answer_530519

编辑：Alan Stevens 2020-11-1

在 MATLAB Online 中打开

Like this?

g = 9.81; 
theta0 = 45*pi/180; 
v0=5; 
dt = 1/128;
ntimes = 400;
tend = ntimes*dt;
t = linspace(0,tend,ntimes);
vx = v0*cos(theta0);
vy = v0*sin(theta0);
x = 0; y = 0; 
xmax = vx*tend;
plot(x,y, 'o', 'MarkerFaceColor','b', 'MarkerSize', 8)
axis([0 xmax 0 .8]); 
M(1) = getframe;
treset = 0;
for i = 1:ntimes
    
    x = vx*t(i);
    tm = t(i) - treset;
    y = vy * tm - 0.5*g*tm^2; 
    plot(x,y, 'o', 'MarkerFaceColor', 'b','markerSize', 8);
    axis([0 xmax 0 .8]);
    M(i)= getframe; 
    if y<0
        y = 0;
        vy = 0.8*vy;
        treset = t(i);
    end
      
end
close
pause(1)
movie(M, 1, 50)