Matplotlib animation.FuncAnimation() 动画错过第一帧？
Matplotlib animation.FuncAnimation() animation miss first frame?
我是 Python 和 Matplotlib 的新手。我有这段代码可以在 3d Matplotlib 子图中绘制轨迹：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
### devo duplicare primo elemento della lista altrimenti skippa a visualizzare i primi due sul video
# trajectory = [(2.5, 3.5, 27.5),(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
except:
print('coord empty')
return
if pippo:
pippo.remove()
print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False) # e' necessario
plt.show()
plt.close('all')
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
print('#####################')
i = islice(trajectory, 0 , len(trajectory), 1)
ani2 = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False)
# writervideo = animation.FFMpegWriter(fps=1, codec="h264")
# ani2.save('video_steeper.mp4', writer=writervideo)
ani2.save("movie.gif", writer=animation.PillowWriter(fps=1))
我正在努力理解为什么要制作正确的动画并保存动画我需要复制 trajectory 列表的第一个元素 ((2.5, 3.5, 27.5))。
如果我不这样做，动画和我的 gif 只显示 9 个点而不是 10 个点，请查看结果输出：
来自 10 个元素列表的电影 trajectory :
来自 11 个元素列表的电影 trajectory（第一个重复）：
我已经尝试了很多来弄清楚发生了什么但无法理解，奇怪的是我在 animate 函数中的 print 语句准确地打印了 11 和 10 点两个不同的列表，但它们都错过了动画和文件中的帧。有什么线索吗？
在我看来，您的问题来自您正在创建的可迭代 i 和函数 next 的使用。我不确定为什么会发生这种情况，但是如果您不创建可迭代对象 i 而只是直接索引您的轨迹，那么您的动画会按预期工作。
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
x = trajectory[j][0]
y = trajectory[j][1]
z = trajectory[j][2]
if pippo is not None:
pippo.remove()
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False) # e' necessario
plt.show()
输出给出：
很好地摆弄了一下 FuncAnimation 添加一个 init_func :
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
def init_animate():
ax.plot_trisurf(x, y, data, color="green", alpha=0.5)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
except:
print('coord empty')
return
if pippo:
pippo.remove()
print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory),init_func=init_animate, repeat=False)
plt.show()
plt.close('all')
print('#####################')
能够在 gif 上获得所有 10 分：
也能够删除 frames arg 但只是为了可视化而不是保存我的动画，请参阅：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
### devo duplicare primo elemento della lista altrimenti skippa a visualizzare i primi due sul video
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
# trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
def init_animate():
ax.plot_trisurf(x, y, data, color="blue", alpha=0.5)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
print(coord)
except:
print('coord empty')
global ani
global ani2
ani = None
ani2 = None
return
if pippo:
pippo.remove()
# print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
# ani = animation.FuncAnimation(fig, animate ,frames=len(trajectory),init_func=init_animate, interval=1000, repeat=False)
ani = animation.FuncAnimation(fig, animate, init_func=init_animate, interval=1000, repeat=False)
plt.show()
print('test to see if everything is fine')
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
print('#####################')
i = islice(trajectory, 0 , len(trajectory), 1)
ani2 = animation.FuncAnimation(fig, animate, init_func=init_animate, interval=1000, repeat=False).save("movie_init_no-frames.gif", writer=animation.PillowWriter(fps=1))
不知道发生了什么，但算法保持 运行，输出：
len trajectory : 10
(2.5, 3.5, 27.5)
(2.0, 3.0, 21.0)
(1.5, 2.5, 15.5)
(1.0, 2.0, 11.0)
(0.5, 1.5, 7.5)
(0.0, 1.0, 5.0)
(0.0, 0.5, 3.25)
(0.0, 0.0, 2.0)
(0.0, -0.5, 1.25)
(0.0, -1.0, 1.0)
coord empty
test to see if everything is fine
#####################
(2.5, 3.5, 27.5)
(2.0, 3.0, 21.0)
(1.5, 2.5, 15.5)
(1.0, 2.0, 11.0)
(0.5, 1.5, 7.5)
(0.0, 1.0, 5.0)
(0.0, 0.5, 3.25)
(0.0, 0.0, 2.0)
(0.0, -0.5, 1.25)
(0.0, -1.0, 1.0)
coord empty
coord empty
coord empty
^Z
[9]+ Stopped
我想这与 FuncAnimation的内部有关。
尽管如此，我还是应该花时间尝试理解 j 文档
根据 help(matplotlib.animation)
......
class FuncAnimation(TimedAnimation)
| FuncAnimation(fig, func, frames=None, init_func=None, fargs=None, save_count=None, *, cache_frame_data=True, **kwargs)
|
| Makes an animation by repeatedly calling a function *func*.
|
| Parameters
| ----------
| fig : `~matplotlib.figure.Figure`
| The figure object used to get needed events, such as draw or resize.
|
| func : callable
| The function to call at each frame. The first argument will
| be the next value in *frames*. Any additional positional
| arguments can be supplied via the *fargs* parameter.
|
| The required signature is::
|
| def func(frame, *fargs) -> iterable_of_artists
|
| If ``blit == True``, *func* must return an iterable of all artists
| that were modified or created. This information is used by the blitting
| algorithm to determine which parts of the figure have to be updated.
| The return value is unused if ``blit == False`` and may be omitted in
| that case.
......
我是 Python 和 Matplotlib 的新手。我有这段代码可以在 3d Matplotlib 子图中绘制轨迹：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
### devo duplicare primo elemento della lista altrimenti skippa a visualizzare i primi due sul video
# trajectory = [(2.5, 3.5, 27.5),(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
except:
print('coord empty')
return
if pippo:
pippo.remove()
print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False) # e' necessario
plt.show()
plt.close('all')
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
print('#####################')
i = islice(trajectory, 0 , len(trajectory), 1)
ani2 = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False)
# writervideo = animation.FFMpegWriter(fps=1, codec="h264")
# ani2.save('video_steeper.mp4', writer=writervideo)
ani2.save("movie.gif", writer=animation.PillowWriter(fps=1))
我正在努力理解为什么要制作正确的动画并保存动画我需要复制 trajectory 列表的第一个元素 ((2.5, 3.5, 27.5))。
如果我不这样做，动画和我的 gif 只显示 9 个点而不是 10 个点，请查看结果输出：
来自 10 个元素列表的电影 trajectory :
来自 11 个元素列表的电影 trajectory（第一个重复）：
我已经尝试了很多来弄清楚发生了什么但无法理解，奇怪的是我在 animate 函数中的 print 语句准确地打印了 11 和 10 点两个不同的列表，但它们都错过了动画和文件中的帧。有什么线索吗？
在我看来，您的问题来自您正在创建的可迭代 i 和函数 next 的使用。我不确定为什么会发生这种情况，但是如果您不创建可迭代对象 i 而只是直接索引您的轨迹，那么您的动画会按预期工作。
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
x = trajectory[j][0]
y = trajectory[j][1]
z = trajectory[j][2]
if pippo is not None:
pippo.remove()
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory), repeat=False) # e' necessario
plt.show()
输出给出：
很好地摆弄了一下 FuncAnimation 添加一个 init_func :
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
def init_animate():
ax.plot_trisurf(x, y, data, color="green", alpha=0.5)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
except:
print('coord empty')
return
if pippo:
pippo.remove()
print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
ani = animation.FuncAnimation(fig, animate, interval=1000, frames=len(trajectory),init_func=init_animate, repeat=False)
plt.show()
plt.close('all')
print('#####################')
能够在 gif 上获得所有 10 分：
也能够删除 frames arg 但只是为了可视化而不是保存我的动画，请参阅：
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from itertools import islice
import sympy as sym
from sympy.parsing.sympy_parser import parse_expr
from sympy import Eq, solve
class FunZ:
def __init__(self, f):
self.x, self.y = sym.symbols('x y')
self.f = parse_expr(f)
# print('f : ', self.f)
def evalu(self, xx, yy):
return float(self.f.subs({self.x: xx, self.y: yy}).evalf())
def derX(self, xx, yy):
self.dx = sym.diff(self.f, self.x)
# print('dx : ', self.dx)
return float(self.dx.subs({self.x: xx, self.y: yy}).evalf())
def derY(self, xx, yy):
self.dy = sym.diff(self.f, self.y)
# print('dy :', self.dy)
return float(self.dy.subs({self.x: xx, self.y: yy}).evalf())
def derXY(self, xx, yy):
return [float(self.derX(xx, yy)), float(self.derY(xx, yy))]
def minim(self):
self.dx = sym.diff(self.f, self.x)
self.dy = sym.diff(self.f, self.y)
print('dx : ', self.dx)
print('dy : ', self.dy)
eq1 = Eq(self.dx ,0)
eq2 = Eq(self.dy ,0)
solu = solve((eq1,eq2), (self.x, self.y), dict= False)
print(solu, type(solu))
return solu
XX = np.linspace(-4, 4, 100)
YY = np.linspace(-4, 4, 100)
funz = FunZ('x**2 + y**2 + 2*y + 2')
ij = [(x, y, funz.evalu(x, y)) for x in XX for y in YY]
arr = np.array(ij, dtype=float)
# print(arr, arr.size, arr.shape, arr.dtype)
der_x = [(a, b, funz.derX(a, b)) for a in XX for b in YY]
derX = np.array(der_x)
# print(derX, derX.size, derX.shape, derX.dtype)
der_y = [(a, b, funz.derY(a, b)) for a in XX for b in YY]
derY = np.array(der_y)
# print(derY, derY.size, derY.shape, derY.dtype)
x = arr[:, 0]
y = arr[:, 1]
data = arr[:, 2]
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
### devo duplicare primo elemento della lista altrimenti skippa a visualizzare i primi due sul video
trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
# trajectory = [(2.5, 3.5, 27.5), (2.0, 3.0, 21.0), (1.5, 2.5, 15.5), (1.0, 2.0, 11.0), (0.5, 1.5, 7.5), (0.0, 1.0, 5.0), (0.0, 0.5, 3.25), (0.0, 0.0, 2.0), (0.0, -0.5, 1.25), (0.0, -1.0, 1.0)]
print('len trajectory : ', len(trajectory))
i = islice(trajectory, 0 , len(trajectory), 1)
def init_animate():
ax.plot_trisurf(x, y, data, color="blue", alpha=0.5)
pippo = None
def animate(j): #funziona senza stop iteration with animation.save
global pippo
try:
coord = next(i)
print(coord)
except:
print('coord empty')
global ani
global ani2
ani = None
ani2 = None
return
if pippo:
pippo.remove()
# print(coord)
x = coord[0]
y = coord[1]
z = coord[2]
pippo = ax.scatter(x,y,z)
return pippo
# ani = animation.FuncAnimation(fig, animate ,frames=len(trajectory),init_func=init_animate, interval=1000, repeat=False)
ani = animation.FuncAnimation(fig, animate, init_func=init_animate, interval=1000, repeat=False)
plt.show()
print('test to see if everything is fine')
fig = plt.figure()
ax = fig.add_subplot(projection='3d')
ax.set_xlim([-4,4])
ax.set_ylim([-4,4])
ax.set_zlim([-3,50])
ax.plot_trisurf(x, y, data, color="red", alpha=0.5)
print('#####################')
i = islice(trajectory, 0 , len(trajectory), 1)
ani2 = animation.FuncAnimation(fig, animate, init_func=init_animate, interval=1000, repeat=False).save("movie_init_no-frames.gif", writer=animation.PillowWriter(fps=1))
不知道发生了什么，但算法保持 运行，输出：
len trajectory : 10
(2.5, 3.5, 27.5)
(2.0, 3.0, 21.0)
(1.5, 2.5, 15.5)
(1.0, 2.0, 11.0)
(0.5, 1.5, 7.5)
(0.0, 1.0, 5.0)
(0.0, 0.5, 3.25)
(0.0, 0.0, 2.0)
(0.0, -0.5, 1.25)
(0.0, -1.0, 1.0)
coord empty
test to see if everything is fine
#####################
(2.5, 3.5, 27.5)
(2.0, 3.0, 21.0)
(1.5, 2.5, 15.5)
(1.0, 2.0, 11.0)
(0.5, 1.5, 7.5)
(0.0, 1.0, 5.0)
(0.0, 0.5, 3.25)
(0.0, 0.0, 2.0)
(0.0, -0.5, 1.25)
(0.0, -1.0, 1.0)
coord empty
coord empty
coord empty
^Z
[9]+ Stopped
我想这与 FuncAnimation的内部有关。
尽管如此，我还是应该花时间尝试理解 j 文档
根据 help(matplotlib.animation)
......
class FuncAnimation(TimedAnimation)
| FuncAnimation(fig, func, frames=None, init_func=None, fargs=None, save_count=None, *, cache_frame_data=True, **kwargs)
|
| Makes an animation by repeatedly calling a function *func*.
|
| Parameters
| ----------
| fig : `~matplotlib.figure.Figure`
| The figure object used to get needed events, such as draw or resize.
|
| func : callable
| The function to call at each frame. The first argument will
| be the next value in *frames*. Any additional positional
| arguments can be supplied via the *fargs* parameter.
|
| The required signature is::
|
| def func(frame, *fargs) -> iterable_of_artists
|
| If ``blit == True``, *func* must return an iterable of all artists
| that were modified or created. This information is used by the blitting
| algorithm to determine which parts of the figure have to be updated.
| The return value is unused if ``blit == False`` and may be omitted in
| that case.
......