In [4]:
fig = plt.figure(figsize = (3*pi, 3.9))
ax = fig.add_subplot(xlim = (-pi, pi),
ylim = (-1.3, 1.3))
ax.set_title("Ratio of Center of Mass in High Jump", fontsize = 24)
#Remove axes and ticks.
ax = clearAx(ax)
font1 = {'size' : 16}
font2 = {'size' : 20}
#Fifteen artists:
#circle, center, r1, r2, r3, blockout,
#phi left, phi right, phi value, a/b ratio
#a, b, a line, b line, center of mass line
circ = mpC((0,0),
radius = 1,
edgecolor = body,
facecolor = "#FFFFFF",
lw = 2,
zorder = 1)
center = mpC((0, 0),
radius = 0.05,
edgecolor = dot,
facecolor = dot,
lw = 2,
zorder = 3)
r1 = mpL(xy = [(0, 0), (0, -1)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
r2 = mpL(xy = [(0, 0), (0, -1)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
r3 = mpL(xy = [(0, -1), (0, 0)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
rect = mpR((-pi, -2.1),
height = 1,
width = 2*pi,
edgecolor = "#FFFFFF",
facecolor = "#FFFFFF",
lw = 1,
zorder = 2)
phi_l = ax.text(0, 0, '', c = dot, ha = 'right', va = 'bottom', **font1)
phi_r = ax.text(0, 0, '', c = dot, ha = 'left', va = 'bottom', **font1)
phi = ax.text(pi-0.65, -0.82, '', c = 'k', ha = 'left', **font2)
ratio = ax.text(pi-0.65, -1.17, '', c = "k", ha = 'left', **font2)
#Ratio Details.
a_l = mpL(xy = [(-pi+0.1, -1), (0, -1)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
com_l = mpL(xy = [(-pi+0.1, 0), (0, 0)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
b_l = mpL(xy = [(-pi+0.1, 1), (0, 1)],
edgecolor = dot,
facecolor = dot,
ls = ':',
lw = 1,
zorder = 3)
a_text = ax.text(-pi+0.1, -0.5, '', c = dot, ha = 'center', va = 'center', **font1)
b_text = ax.text(-pi+0.1, 0.5, '', c = dot, ha = 'center', va = 'center', **font1)
def init():
"""Initialize fifteen artists."""
ax.add_patch(circ)
ax.add_patch(center)
ax.add_patch(r1)
ax.add_patch(r2)
ax.add_patch(r3)
ax.add_patch(rect)
phi_l.set_text('ϕ')
phi_r.set_text('ϕ')
phi.set_text('')
ratio.set_text('')
ax.add_patch(a_l)
ax.add_patch(com_l)
ax.add_patch(b_l)
a_text.set_text('a')
b_text.set_text('b')
return circ, center, r1, r2, r3, rect, phi_l, phi_r, phi, ratio, a_l, com_l, b_l, a_text, b_text
def animate(i):
if i < 360 :
t = 180 - i/2
tr = pi*t/180
r = 180 / t
c = (0, 1-r)
x = r*sin(tr)
y = r*cos(tr)+1-r
phi_text = str(t)
#Emphasize the final result.
else :
t = 0
tr = 0
r = 10000
c = (0, -9999)
x = pi
y = 1
phi_text = '0'
#Arc is always 2𝜋, top of circle is always (0,1).
circ.set_radius(r)
circ.set_center(c)
#Center.
#Average out full semicircle above and circle sections below.
if i < 180 :
com = pi*(r-1)/2 - r*sin(tr)*cos(tr)/2 - r + 1
ans = (com-y) / (1-com)
#Circle section above only.
elif i < 360 :
com = pi / (2*sin(tr)) + r*cos(tr)/2 - r + 1
ans = (com-y) / (1-com)
#Emphasize the final result.
else :
com = 1
ans = 2
ratio_text = str(round(ans, 4))
center.set_center((0, com))
#Radii
r1.set_xy([c, (x, y)])
r2.set_xy([c, (-x, y)])
r3.set_xy([(0, 1), c])
#Blockout.
rect.set_height(y+2.09)
#Where is ϕ?
if i < 202 :
phi_l.set_x(0.2)
phi_l.set_y(c[1]+0.1)
phi_r.set_x(-0.2)
phi_r.set_y(c[1]+0.1)
else :
phi_l.set_y(-1.2)
phi_r.set_y(-1.2)
if i < 360 :
trace = (pi-0.4)*(i-202)/(158*2)+0.2
phi_l.set_x(trace)
phi_r.set_x(-trace)
else :
phi_l.set_x(pi/2)
phi_r.set_x(-pi/2)
#Info.
phi.set_text("ϕ : " + phi_text + "°")
ratio.set_text("a/b : " + ratio_text)
#Ratio info.
a_l.set_xy([(-pi+0.1, y), (x, y)])
com_l.set_xy([(-pi+0.1, com), (0, com)])
a_text.set_y((y+com)/2)
b_text.set_y((1+com)/2)
return circ, center, r1, r2, rect, phi_l, phi_r, phi, ratio, a_l, com_l, b_l, a_text, b_text
#Run animation.
anim = FA(fig, animate, init_func = init, frames = 400, interval = 25, blit = True)
#Save animation.
anim.save('2024.08.16 EC.mp4');
