def test_pp():
coef = np.array([[1, 1], [0, 0]]) # linear from 0 to 2 @UnusedVariable
# quadratic from 0 to 1 and 1 to 2.
coef = np.array([[1, 1], [1, 1], [0, 2]])
dc = pl.polyder(coef, 1)
c2 = pl.polyint(dc, 1) # @UnusedVariable
breaks = [0, 1, 2]
pp = PPform(coef, breaks)
pp(0.5)
pp(1)
pp(1.5)
dpp = pp.derivative()
import matplotlib.pyplot as plt
x = np.linspace(-1, 3)
plt.plot(x, pp(x), x, dpp(x), '.')
plt.show()
def test_pp():
coef = np.array([[1, 1], [0, 0]]) # linear from 0 to 2 @UnusedVariable
# quadratic from 0 to 1 and 1 to 2.
coef = np.array([[1, 1], [1, 1], [0, 2]])
dc = pl.polyder(coef, 1)
c2 = pl.polyint(dc, 1) # @UnusedVariable
breaks = [0, 1, 2]
pp = PPform(coef, breaks)
pp(0.5)
pp(1)
pp(1.5)
dpp = pp.derivative()
import matplotlib.pyplot as plt
x = np.linspace(-1, 3)
plt.plot(x, pp(x), x, dpp(x), '.')
plt.show()
def integrate(self):
"""
Return the indefinite integral of the piecewise polynomial
"""
cof = pl.polyint(self.coeffs)
pieces = len(self.breaks) - 1
if 1 < pieces:
# evaluate each integrated polynomial at the right endpoint of its
# interval
xs = diff(self.breaks[:-1, ...], axis=0)
index = np.arange(pieces - 1)
vv = xs * cof[0, index]
k = self.order
for i in range(1, k):
vv = xs * (vv + cof[i, index])
cof[-1] = np.hstack((0, vv)).cumsum()
return PPform(cof, self.breaks, fill=self.fill)
def integrate(self):
"""
Return the indefinite integral of the piecewise polynomial
"""
cof = pl.polyint(self.coeffs)
pieces = len(self.breaks) - 1
if 1 < pieces:
# evaluate each integrated polynomial at the right endpoint of its
# interval
xs = diff(self.breaks[:-1, ...], axis=0)
index = np.arange(pieces - 1)
vv = xs * cof[0, index]
k = self.order
for i in range(1, k):
vv = xs * (vv + cof[i, index])
cof[-1] = np.hstack((0, vv)).cumsum()
return PPform(cof, self.breaks, fill=self.fill)
