In [1]:

    

%matplotlib inline

import numpy as np
from numpy import pi, sin, cos, sqrt

import matplotlib.pyplot as plt
from matplotlib import animation, rc
from IPython.display import HTML


    

In [2]:

    

print(animation.writers.list())


    

    




['html']

In [3]:

    

#input parameters
r = 1.0  # crank radius
l = 4.0  # connecting rod length
rot_num = 4 # number of crank rotations
increment = 0.1 # angle incremement


    

In [4]:

    

#create the angle array, where the last angle is the number of rotations*2*pi
angle_minus_last = np.arange(0,rot_num*2*pi,increment)
angles = np.append(angle_minus_last, rot_num*2*pi)


    

In [5]:

    

X1=np.zeros(len(angles)) # array of crank x-positions: Point 1
Y1=np.zeros(len(angles)) # array of crank y-positions: Point 1
X2=np.zeros(len(angles)) # array of rod x-positions: Point 2
Y2=np.zeros(len(angles)) # array of rod y-positions: Point 2


    

In [6]:

    

#find the crank and connecting rod positions for each angle
for index,theta in enumerate(angles, start=0):

        x1 = r*cos(theta) # x-cooridnate of the crank: Point 1
        y1 = r*sin(theta) # y-cooridnate of the crank: Point 1
        x2 = 0 # x-coordinate of the rod: Point 2
        # y-coordinate of the rod: Point 2
        y2 = ((r*cos(theta-pi/2)) + (sqrt((l**2)-(r**2)*((sin(theta-pi/2))**2))))
        
        X1[index]=x1 #grab the crank x-position
        Y1[index]=y1 #grab the crank y-position
        X2[index]=x2 #grab the rod x-position
        Y2[index]=y2 #grab the rod y-position


    

In [7]:

    

# set up the figure and subplot
fig = plt.figure()
ax = fig.add_subplot(111, aspect='equal', autoscale_on=False, xlim=(-4,4), ylim=(-2,6))
ax.grid()
line, = ax.plot([], [], 'o-', lw=5, color='g')


    

In [8]:

    

# initialization function
def init():
        line.set_data([], [])
        return (line,)


    

In [9]:

    

# animation function
def animate(i):
        thisx = [0, X1[i], X2[i]]
        thisy = [0, Y1[i], Y2[i]]

        line.set_data(thisx, thisy)
        return line,


    

In [10]:

    

ani = animation.FuncAnimation(fig, animate, init_func=init, frames=len(X1), interval=20, blit=True, repeat=False)


    

In [11]:

    

HTML(ani.to_html5_video())


    

    




---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-11-f47e5100e4fd> in <module>()
----> 1 HTML(ani.to_html5_video())

~\Anaconda3\envs\staticsite\lib\site-packages\matplotlib\animation.py in to_html5_video(self, embed_limit)
   1407                 # We create a writer manually so that we can get the
   1408                 # appropriate size for the tag
-> 1409                 Writer = writers[rcParams['animation.writer']]
   1410                 writer = Writer(codec='h264',
   1411                                 bitrate=rcParams['animation.bitrate'],

~\Anaconda3\envs\staticsite\lib\site-packages\matplotlib\animation.py in __getitem__(self, name)
    168         if not self.avail:
    169             raise RuntimeError("No MovieWriters available!")
--> 170         return self.avail[name]
    171 
    172 writers = MovieWriterRegistry()

KeyError: 'ffmpeg'

In [12]:

    

# equivalent to rcParams['animation.html'] = 'html5'
rc('animation', html='html5')


    

In [13]:

    

ani


    

    




---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
~\Anaconda3\envs\staticsite\lib\site-packages\IPython\core\formatters.py in __call__(self, obj)
    343             method = get_real_method(obj, self.print_method)
    344             if method is not None:
--> 345                 return method()
    346             return None
    347         else:

~\Anaconda3\envs\staticsite\lib\site-packages\matplotlib\animation.py in _repr_html_(self)
   1482         fmt = rcParams['animation.html']
   1483         if fmt == 'html5':
-> 1484             return self.to_html5_video()
   1485         elif fmt == 'jshtml':
   1486             return self.to_jshtml()

~\Anaconda3\envs\staticsite\lib\site-packages\matplotlib\animation.py in to_html5_video(self, embed_limit)
   1407                 # We create a writer manually so that we can get the
   1408                 # appropriate size for the tag
-> 1409                 Writer = writers[rcParams['animation.writer']]
   1410                 writer = Writer(codec='h264',
   1411                                 bitrate=rcParams['animation.bitrate'],

~\Anaconda3\envs\staticsite\lib\site-packages\matplotlib\animation.py in __getitem__(self, name)
    168         if not self.avail:
    169             raise RuntimeError("No MovieWriters available!")
--> 170         return self.avail[name]
    171 
    172 writers = MovieWriterRegistry()

KeyError: 'ffmpeg'





    
Out[13]:





<matplotlib.animation.FuncAnimation at 0x2217c61d0f0>

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