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@DefinitelyMaybe
Last active November 29, 2016 10:19
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matplotlib can be installed via pip
import matplotlib.pyplot as plt
import math
def SmoothUpdate(objPos, objVel, finPos, deltaTime, dampingRatio, angularFrequency):
"""
This function is a derivative of work done by:
Copyright (c) 2008-2012 Ryan Juckett
http://www.ryanjuckett.com/
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
"""
if dampingRatio < 0 or angularFrequency < 0:
print("The damp ratio and angular frequency must be greater than 0.")
return
#initial position and velocity relative to the finish position
x0 = objPos - finPos
v0 = objVel
if dampingRatio > 1:
#over-damped equation
za = -angularFrequency * dampingRatio
zb = angularFrequency * math.sqrt(dampingRatio*dampingRatio - 1)
z1 = za - zb
z2 = za + zb
exp1 = math.exp( z1 * deltaTime )
exp2 = math.exp( z2 * deltaTime )
#update motion
c1 = (v0 - x0 * z2) / (-2 * zb) # z1 - z2 = -2*zb
c2 = x0 - c1
return finPos + c1*exp1 + c2*exp2 #objPos =
#objVel = c1*z1*exp1 + c2*z2*exp2
elif dampingRatio == 1:
#critically damped equation
exp1 = math.exp( -angularFrequency * deltaTime )
#update motion
c1 = v0 + angularFrequency * x0
c2 = x0
c3 = (c1*deltaTime + c2) * exp1
return finPos + c3 #objPos =
#objVel = (c1*exp1) - (c3*angularFrequency)
else:
#under-damped equation
w = angularFrequency * dampingRatio #omegaZeta
a = angularFrequency * math.sqrt(1 - dampingRatio*dampingRatio)
exp1 = math.exp( -w * deltaTime )
cos1 = math.cos( a * deltaTime )
sin1 = math.sin( a * deltaTime )
#update motion
c1 = x0
c2 = (v0 + w*x0) / a
return finPos + exp1*(c1*cos1 + c2*sin1) #objPos =
#objVel = -exp1*( (c1*w - c2*a)*cos1 + (c1*a + c2*w)*sin1)
plt.grid(True)
#x axis
xrange1 = [(2*math.pi*i)/32 for i in range(64)]
#y axis
yrange1 = [math.cos(i) for i in xrange1]
#yrange2 = [0 for i in xrange1]
#yrange2 = [math.cos(i)/math.pow(math.e, i) for i in xrange1]
#yrange3 = [-i/(2*math.pi) + 1 for i in xrange1]
#yrange4 = [math.cos(i)/math.pow(math.e, i) for i in xrange1]
yrange2 = [SmoothUpdate(1, 0, 0, i, 2, 1) for i in xrange1]
yrange3 = [SmoothUpdate(1, 0, 0, i, 1, 1) for i in xrange1]
yrange4 = [SmoothUpdate(1, 0, 0, i, .75, 1) for i in xrange1]
yrange5 = [SmoothUpdate(1, 0, 0, i, .5, 1) for i in xrange1]
plt.plot(xrange1, yrange1, "-", xrange1, yrange2, "-", xrange1, yrange3, "-", xrange1, yrange4, "-", xrange1, yrange5, "-")
plt.show()
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